CN102444396B

CN102444396B - A kind of natural gas production method

Info

Publication number: CN102444396B
Application number: CN201210001267.3A
Authority: CN
Inventors: 李向东
Original assignee: Individual
Current assignee: Beijing Hezhong Beneficial Technology LLC
Priority date: 2012-01-04
Filing date: 2012-01-04
Publication date: 2016-08-03
Anticipated expiration: 2032-01-04
Also published as: CN102444396A

Abstract

The invention discloses a kind of natural gas production method, comprise the steps: 1) insulated tubing is put in Wellbore of Gas Wells sleeve pipe or in oil pipe；2) natural gas is allowed to rise to well head by insulated tubing.The present invention can make full use of natural energy in natural gas produces and produce natural gas, the wellhead temperature of the natural gas well can be greatly improved, can effectively solve the problem that hydrate affects the problem that natural gas produces, be capable of natural gas do not heat, not supercharging production technology, heating furnace heating, the defeated link of compressor boost collection can be cancelled, it is possible to production cost and energy consumption that natural gas produce are greatly reduced；Have and implement the excellent features such as easy, safe and reliable.

Description

A kind of natural gas production method

Technical field

The present invention relates to natural gas production field, especially relate to a kind of natural gas production method.

Background technology

At present, domestic commonly used oil pipe method, tiretube process, coiled tubing method produce natural gas, can be divided into the most again surface throttling oil pipe method, downhole choke oil pipe method, surface throttling tiretube process, downhole choke tiretube process, surface throttling coiled tubing method, downhole choke coiled tubing method.

One, surface throttling oil pipe method: the method is first to allow the natural gas in underground gas storage layer (abbreviation gas-bearing formation) rise to well head by the oil pipe in Wellbore of Gas Wells, then natural gas is allowed to enter gathering line from well head, first pass through the heating furnace being arranged at well site or gas gathering station heated by natural gas is heated up, and carry out reducing pressure by regulating flow after heated by natural gas heats up, allow the natural gas after reducing pressure by regulating flow enter the defeated operation of subsequent set the most again.There is following defect in the method:

1), the well head stage is risen to from shaft bottom at natural gas, owing to the oil pipe in natural gas well pit shaft is common metal blank tubing, natural gas constantly dispels the heat to stratum during shaft bottom rises to well head, therefore when natural gas lift to well head, before entering heating furnace heating, reducing pressure by regulating flow, its temperature may generate critical temperature already below gas hydrates, thus forms Hydrate Plugging pit shaft, well head, causes gas well normally to produce.And when pit shaft, well head are blocked by gas hydrates, the most generally take the method adding methanol to release blocking.

From open source information: domestic gas well commonly uses oil pipe and produces natural gas, and oil pipe used is metal blank tubing.

" the big NIUDI low pressure densification Gas Reservoir transformation theory and practice " of the 1st edition the 1st printing in Sinopec publishing house January in 2009 page 12 inverse the 1st row once stated that " reservoir temperature is 78.8～90.96 DEG C, belongs to moderate formation temperature.”

From knowledge known in this field: Soviet Union's Sulige gas field gas well average well depth 3500 meters, reservoir temperature about 110 DEG C, general smooth gas field gas well average well depth 6000 meters, reservoir temperature about 180 DEG C.

From knowledge known in this field: oil pipe at present used in gas well, sleeve pipe, as the plain tubing used by oil well, sleeve pipe, are metal blank tubing.

From knowledge known in this field: in pit shaft, natural gas can pass sequentially through annular space-casing wall-cementing concrete hoop the earth heat radiation of tubing wall-casing tube composition, and the radiating rate of natural gas, heat dissipation capacity and its temperature positive correlation.

" oilfield chemistry " page 277 the 2nd～3 row of publishing house of China University Of Petroleum Beijing the 1st edition the 1st printing July in 2000 were once stated: " under certain condition, natural gas can generate hydrate with water, makes natural gas line produce blocking." should once state by " oilfield chemistry " page 269 10-11 row: " under formation conditions, natural gas contacts with water, therefore total containing a number of steam in natural gas.”

Open source information shows: the natural gas having and aqueous water association, when natural gas flows out from gas-bearing formation, can be formed with the aqueous water of its association and flow together with fluid-mixing.

Being 47 DEG C from the critical generation temperature of " oilfield chemistry " the 277th page table 9-3: methane hydrate, the critical generation temperature of ethane hydrates is 14.5 DEG C.

Described in " big NIUDI low pressure densification Gas Reservoir transformation theory and practice " page 11 inverse the 10th row: " in DaNiuDi gas field gas component, methane content is the highest, and the above constituent content of ethane is relatively low.”

From knowledge known in this field: owing to natural gas density, static pressure are the lowest, natural gas well well head pressure is the highest, as gas field of pacifying the border region, Yulin Gas Field, DaNiuDi gas field, the pressure of Soviet Union's Sulige gas field natural gas well head may be up to more than 20MPa, the pressure of general smooth gas field natural gas well mouth is more than 40MPa.

As a example by gas field of pacifying the border region.

Open source information shows: gas field of pacifying the border region is positioned at Ordos, inner Mongolia desert area and Jingbian County, Shaanxi Province is domestic, and winter minimum temperature reaches-31 DEG C.

The operational data in gas field of pacifying the border region shows: natural gas well average well depth about 3500 meters, shaft bottom gas-bearing formation temperature about 110 DEG C, general daily output tolerance 1～50,000 mark side/day, part gas well daily output tolerance is more than 50,000 mark sides/day, part gas well daily output tolerance is less than 10,000 mark sides/day, gas well all uses plain tubing, sleeve structure, oil pipe used, sleeve pipe to be metal blank tubing.Gas well mouth oil pipe outlet pressure, typically at more than 15MPa, reaches as high as more than 22MPa, and surveying gas well mouth natural gas temperature winter is 8～15 DEG C, and surveying gas well mouth natural gas temperature summer is 10～25 DEG C.

The mode of production in this gas field can be summarized as: after natural gas rises to well head by oil pipe, enters buried gathering line, is delivered to gas gathering station by buried gathering line, first passes through heating furnace heat temperature raising, then reducing pressure by regulating flow in gas gathering station.

Being calculated from knowledge known in this field: pressure is the highest, it is the highest that gas hydrates generate critical temperature, and vice versa.When gas field gas pressure of pacifying the border region is 20MPa, it is 22.1 DEG C that corresponding gas hydrates generate critical temperature；When pressure is 6.4MPa, it is 14.2 DEG C that corresponding gas hydrates generate critical temperature.

Therefore, when this gas field produces in the winter time, the natural gas well has possessed hydrate formation conditions for natural gases at upper wellbore, well head, if not solved, will block upper wellbore, well head, and causing closing a well in.

This gas field uses to pit shaft (oil pipe or sleeve pipe) or/and the method adding methanol in the surface gathering and transferring pipeline of well site prevents hydrate or ice blocking pit shaft, well head, gathering line and pipe fitting.During winter production, this gas field individual well adds 100～1200L/ days of methanol to pit shaft (oil pipe or sleeve pipe) and well site surface gathering and transferring pipeline average every day.

2) in natural gas well site surface gathering and transferring stage before well head out enters buried gathering line, if not in well site to heated by natural gas, reducing pressure by regulating flow, because of natural gas the most outwards heat radiation after well head enters well site gathering line, pipe fitting on the ground, natural gas temperature constantly reduces, its on the ground the temperature in gathering line, pipe fitting may generate critical temperature already below gas hydrates, thus form Hydrate Plugging gathering line, pipe fitting on the ground, cause gas well normally to produce.And when ground gathering line, pipe fitting are blocked by gas hydrates, the most generally take the method adding methanol to release blocking.

From knowledge known in this field: be limited to well site production technology and production management's requirement, the gas well pipe fitting in well site such as valve, effusion meter etc. are necessarily placed at ground, forbid burying in underground.

From knowledge known in this field: existing heat preserving method can not produce heat, it is impossible to is used as heating means, it is impossible to 100% stops heat radiation, however it remains diabatic process.

From knowledge known in this field: gas field, current domestic south gas well mouth, surface line do not require insulation, and northern cold cold air field gas well mouth, surface line major part are not incubated, only only a few well head, surface line insulation.Gas field as each in Ordos Basin is not incubated except Soviet Union 10, other well heads of reviving in addition to 11 blocks, surface line.Therefore, the natural gas temperature being positioned at well head gathering line below is inevitably less than wellhead temperature, therefore when temperature is less than-25 DEG C, even if well head is formed without Hydrate Plugging, is likely to form Hydrate Plugging in surface line on well site, pipe fitting.

From knowledge known in this field: the current domestic commonly used method adding methanol releases well site surface line, pipe fitting Hydrate Plugging.

3) leave well site surface line at natural gas, enter the collection defeated stage before buried gathering line extremely enters gas gathering station heating furnace, if not to heated by natural gas intensification, reducing pressure by regulating flow, because natural gas can be by underground gathering line, pipe fitting to the earth constantly heat radiation after entering buried gathering line, natural gas temperature constantly reduces, in may making gathering line, natural gas temperature generates critical temperature less than hydrate, thus form Hydrate Plugging gathering line, cause gas well normally to produce.And when gathering line is blocked by gas hydrates, the most generally take the method adding methanol to release blocking.

From knowledge known in this field: not to heated by natural gas intensification, the gas field of reducing pressure by regulating flow before gas gathering station, it is not incubated by gas gathering pipeline, the pipe fitting of well head to gas gathering station, the general buried degree of depth is 1.5～2 meters (freezing below layer), gathering line such as gas field of pacifying the border region is not incubated, and design buried depth is 1.6 meters.

Open source information shows: 1.5～2 meters of area of China's overwhelming majority (freezing below layer) stratum year-round average temperature is less than 10 DEG C.The similar formation temperature of each gas field is no exception, and the stratum year-round average temperature of gas field 1.5 as each in Ordos Basin～2 meters (freezing below layer) is less than 10 DEG C, winter, minimum ground temperature was less than 5 DEG C.

As a example by gas field of pacifying the border region.

Calculated from knowledge known in this field: if this gas field gas gathering pipeline fed distance is 4500 meters, flow is 80,000 mark sides/day, wellhead temperature is 25 DEG C, well mouth oil pipe outlet pressure 20MPa, then this gathering line natural gas temperature after 4500 meters of fed distance will drop to less than 10 DEG C, pressure then can not be less than 15MPa, and therefore the natural gas temperature in this gathering line has been far below hydrate and has generated critical temperature.

The operational data in gas field of pacifying the border region shows: this gas field uses high pressure to add methanol gathering and transportation technology, quantity of methyl alcohol is added the highest during winter production, natural gas did not heated before entering gas gathering station, did not throttled to well mouth oil pipe (or sleeve pipe) or/and add 200～1200L/ days of methanol in the surface gathering and transferring pipeline of well site average every day.In gas well mouth, well site gathering line, buried gathering line, gas gathering station on the ground, gathering line is not incubated on the ground, well head is 500～ten thousand metres to the defeated distance of collection (also known as collecting defeated radius) of gas gathering station, the gathering line design buried degree of depth 1.6 meters (freezing 1.5 meters of layer), surveying 1.6 meter layer year-round average temperature is 9 DEG C.This gas field gas well well mouth oil pipe outlet pressure typically at more than 15MPa, up to more than 22MPa.This gas field actual measurement gas well mouth natural gas temperature in winter is 8～15 DEG C, and it is 15～22MPa that actual measurement gathering line in winter enters the gas pressure of gas gathering station, and it is-4～9 DEG C that actual measurement gathering line in winter enters the natural gas temperature of gas gathering station.

Calculated from knowledge known in this field: the defeated natural gas of this gas field gathering line collection in winter is before entrance gas gathering station, temperature generates critical temperature less than hydrate the most, some gathering line inlet temperatures are already below the freezing point of water, if not adding methanol by pit shaft or well site gathering line, all there is Hydrate Plugging issue pipeline from the gathering line of well head to gas gathering station in all gas wells, some gathering lines also can exist icing frozen block problem.

4) if first well head heated by natural gas out is heated up in well site, reducing pressure by regulating flow, it is delivered to gas gathering station the most again by gathering line, not only need to arrange special heating furnace or other firing equipments in well site, need to consume substantial amounts of natural gas or other energy, and generally require and the ground before entering gas gathering station, underground gathering system are incubated, thus cause natural gas production cost, fixed investment, management workload to be significantly increased.

From knowledge known in this field: from Soviet Union, Sulige gas field gas well gas pressure out is up to 20MPa, the gas pressure in the ultra-deep gas fields such as general smooth gas field is even more than 40MPa, if not by the natural gas reducing pressure by regulating flow of gas well output, not only result in the production facility in gas field own such as gathering line, valve, equipment equal pressure the highest grade, fixed investment is significantly increased, and the outer defeated storing and transporting system pressure rating of natural gas, construction investment can be caused to be significantly increased.Open source information shows: gas east, domestic river send natural gas pipeline projects distribution pressure to be 10MPa, and capital, Shan one line Gas Pipeline Project distribution pressure is 6.4MPa.Therefore, natural gas reducing pressure by regulating flow in the production process leave gas field is inevitable.Such as pacifying the border region gas field, Soviet Union Sulige gas field, DaNiuDi gas field, Yulin Gas Field etc., general requirement outer again after natural gas reducing pressure by regulating flow 3～5MPa will transport to natural gas purification processing factory.

From knowledge known in this field: when natural gas being heated before gas gathering station, reducing pressure by regulating flow time, general use in well site, natural gas is heated, the mode of reducing pressure by regulating flow.

From knowledge known in this field: when natural moral stream blood pressure lowering, the temperature of natural gas is necessarily greatly reduced, and even can be reduced to less than 0 DEG C.Therefore, before reducing pressure by regulating flow, the most first raise natural gas temperature by the method for heating.Open source information shows, domestic gas field commonly uses gas heating furnace heated natural gas.

As a example by Soviet Union's Sulige gas field Su10 Block.

Open source information shows: Su10 Block is positioned at Ordos, inner Mongolia desert area, and winter minimum temperature reaches-31 DEG C.

The operational data of Su10 Block shows: this block natural gas well average well depth about 3500 meters, shaft bottom gas-bearing formation temperature about 110 DEG C, general daily output tolerance 1～50,000 mark side/day, part gas well daily output tolerance is more than 50,000 mark sides/day, part gas well daily output tolerance exceedes less than 10,000 mark sides/day, gas well all uses plain tubing, sleeve structure, oil pipe used, sleeve pipe to be metal blank tubing.Gas well mouth oil pipe outlet pressure is 18～20MPa, and actual measurement well head in winter is 9～17 DEG C without natural gas temperature during heat tracing, and actual measurement well head in summer is 10～30 DEG C without natural gas temperature during heat tracing.Well head is 500～ten thousand metres to the defeated distance of collection (also known as collecting defeated radius) of gas gathering station, and the gathering line design buried degree of depth 1.6 meters (freezing 1.5 meters of layer), surveying 1.6 meter layer year-round average temperature is 9 DEG C, and winter minimum temperature is less than 5 DEG C.

The production technology that this block uses is: natural gas rises to the well head being incubated by hotwater tracing by oil pipe, subsequently into being heated to about 70 DEG C in being arranged at the heating furnace in well site, subsequently into well site surface gathering and transferring valve group reducing pressure by regulating flow to about 4MPa, then by being delivered to gas gathering station with the buried gathering line of yellow jacket polyurethane foam insulation layer insulation.

From knowledge known in this field calculate: pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 20 DEG C to 4MPa time, its temperature will drop to-37.5 DEG C；Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 30 DEG C to 4MPa time, its temperature will drop to-27.8 DEG C；Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 40 DEG C to 4MPa time, its temperature will drop to-16 DEG C；Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 50 DEG C to 4MPa time, its temperature will drop to-2.9 DEG C；Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 60 DEG C to 4MPa time, its temperature will drop to 10.2 DEG C；Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 70 DEG C to 4MPa time, its temperature will drop to 23.1 DEG C.

Calculated from knowledge known in this field: pressure be the Soviet Union Sulige gas field gas hydrates generation critical temperature of 20MPa be 22.1 DEG C；Pressure is that to generate critical temperature be 10.7 DEG C for the Soviet Union Sulige gas field gas hydrates of 4MPa；Thus while pressure be 20MPa, temperature be 30 DEG C Soviet Union's Sulige gas field natural gas will not pit shaft, well head formed hydrate, but when by its pressure by 20MPa reducing pressure by regulating flow to 4MPa, its temperature can be down to-27.8 DEG C.

Therefore, this block is when well site reducing pressure by regulating flow, if natural gas does not first pass through before throttling and is heated to more than 60 DEG C, but from well head out rear directly reducing pressure by regulating flow, in gathering line, pipe fitting, not only necessarily form gas hydrates blocking, and because of this temperature well below the freezing point of water, inevitably result in the vapourous water in natural gas, aqueous water (being also called free water) icing frozen block pipeline.

Calculated from knowledge known in this field: this block is when well site reducing pressure by regulating flow, if the buried gathering line of well site to gas gathering station is not incubated, even if heated by natural gas being warming up to 70 DEG C before Jie Liu, natural gas temperature after its throttling also only 23.1 DEG C, necessarily to the earth heat radiation after entering buried gathering line, may be down to compound generating critical temperature in natural gas temperature after 4500 meters of collection are defeated is less than 10.7 DEG C, even if still high than this gathering line minimum buried ground temperature in winter, Hydrate Plugging gathering line still can be formed.

From Soviet Union's Sulige gas field means of production, this block gas well produced free water salinity is 1～5 × 10⁴Mg/L, corresponding minimum freezing point about-3 DEG C.

5), when natural gas is at gas well well site reducing pressure by regulating flow, owing to natural gas well mouth pressure is the highest, and wellhead temperature is relatively low, if natural gas from well head out after not heat temperature raising may be down to less than-20 DEG C with regard to direct reducing pressure by regulating flow, natural gas temperature.Although being prevented from natural gas with methanol or other antifreezing agents to generate hydrate below-20 DEG C, it also is able to the water freezing prevented in natural gas, it is thus possible to ensure that gas gathering pipeline is unimpeded, but gas gathering pipeline, pipe fitting prolonged cold below-20 DEG C can be caused to run, this is not permitted in natural gas production process, rules and regulations, easily causes major industrial accident.Therefore, natural gas is before reducing pressure by regulating flow, it is necessary to be first heated to uniform temperature.Heating then needs to consume substantial amounts of natural gas.

From knowledge known in this field: during natural gas reducing pressure by regulating flow, temperature necessarily reduces.

From knowledge known in this field: the freezing point of methanol is-97 DEG C, it is possible to the effectively natural gas adsorption hydrate of suppression-20 DEG C, it is possible to effectively prevent the water freezing of-20 DEG C.Same other alcohols such as ethanol, ethylene glycol also are able to effectively suppress the natural gas adsorption hydrate of-20 DEG C, it is possible to effectively prevent the water freezing of-20 DEG C.

From SH3059-2001 " general rule selected by petrochemical pipe design equipment ", natural gas line rank is SHB, is not belonging to the SHD cryogenic piping rank using temperature less than-29 DEG C, and the use temperature of 20# carbon constructional quality steel is-20～425 DEG C.

From knowledge: steel exist brittle transition temperature.

From Soviet Union Sulige gas field, the pacify the border region design in the gas fields such as gas field, construction information: the material that natural gas line uses is generally 20# steel.

From knowledge known in this field: natural gas line, the minimum use temperature of valve are-20 DEG C, pipeline, valve is not allowed to run at a temperature of less than-20 DEG C for a long time.The normal operating temperature of natural gas line should be more than-20 DEG C, otherwise it is possible to there will be serious industrial accident, jeopardize natural gas production safety, the most seriously violate natural gas and produce rules and regulations.

As a example by Soviet Union's Sulige gas field Su10 Block.

From Soviet Union's Sulige gas field Su10 Block operational data: this block uses well site to add thermal throttle production technology, and gas well mouth oil pipe outlet pressure is 18～20MPa, actual measurement well head in winter is 9～30 DEG C without natural gas temperature during heat tracing.

From knowledge known in this field calculate: by pressure be 20MPa, temperature be the Su10 Block natural gas reducing pressure by regulating flow of 30 DEG C to 4MPa time, its temperature will drop to-27.8 DEG C, the minimum use temperature-20 DEG C allowed well below natural gas line, is that natural gas produces not permitted in rules and regulations.

6) if natural gas is not at well head or well site reducing pressure by regulating flow, but first pass through high pressure collection and transport to gas gathering station reducing pressure by regulating flow again.After lowering the temperature due to the natural gas gathering line long distance delivery through well site to gas gathering station, temperature is likely close to the minimum ground temperature of buried pipeline, it is possible to already below gas hydrate synthesis critical temperature, therefore there may be Hydrate Plugging issue pipeline in gathering line.Although adding MeOH methanol or other antifreezing agents by pit shaft or well site surface gathering and transferring pipeline, can effectively prevent natural gas from forming Hydrate Plugging pipeline in buried gathering line, pipe fitting, it also is able to effectively prevent natural gas to be not added with when thermal throttle blood pressure lowering is cooled to below 0 DEG C being formed hydrate in gas gathering station, but owing to natural gas enters into the pressure after gas gathering station the highest from well site, it is not added with thermal throttle blood pressure lowering in gas gathering station and still can produce the biggest temperature drop, even natural gas temperature can be reduced to less than-20 DEG C, will cause natural gas line running temperature for a long time less than-20 DEG C, it it is natural gas production process, not permitted in rules and regulations, easily cause major industrial accident.Therefore, natural gas is when gas gathering station reducing pressure by regulating flow, it is necessary to first heat temperature raising.Heating then needs to consume substantial amounts of natural gas.

As a example by gas field of pacifying the border region.

The gas field means of production for many years of pacifying the border region show: this gas field uses high pressure to add methanol gathering and transportation technology, this technique can be summarized as: during natural gas rises to well head by oil pipe, in gas well, methanol is added by pit shaft oil pipe or sleeve pipe, or when natural gas is risen to well head by oil pipe, entered well site surface gathering and transferring pipeline, pipe fitting, add methanol by well head pipe fitting or well site surface gathering and transferring pipeline；The natural gas carrying methanol does not heats before entering gas gathering station, does not throttles, and is delivered to gas gathering station by buried gathering line from well site；First pass through gas gathering station surface gathering and transferring pipeline, pipe fitting enters heating in the heating furnace being arranged on gas gathering station, and passes through reducing heating coil reducing pressure by regulating flow in heating furnace while heating；Then from heating furnace out, utilize restricting element (such as special choke valve) reducing pressure by regulating flow to 3～5MPa；Then enter back into follow-up point of water of gas gathering station, dehydration, outer defeated etc. collect defeated operation.

This gas field gas well mouth, well site on the ground between gathering line, well site to gas gathering station in buried gathering line, gas gathering station on the ground gathering line pipe fitting etc. be not incubated, well head is 500～ten thousand metres to the defeated distance of collection (also known as collecting defeated radius) of gas gathering station, the gathering line design buried degree of depth 1.6 meters (freezing 1.5 meters of layer), surveying 1.6 meter layer year-round average temperature is 9 DEG C.

Quantity of methyl alcohol is added the highest during this gas field winter production, individual well average every day to well mouth oil pipe (or sleeve pipe) or/and add 200～1200L/ days of methanol in the surface gathering and transferring pipeline of well site, gas well mouth oil pipe outlet pressure typically at more than 15MPa, up to more than 22MPa.This gas field actual measurement gas well mouth natural gas temperature in winter is 8～15 DEG C, and it is 15～22MPa that actual measurement gathering line in winter enters the gas pressure of gas gathering station, and it is-4～9 DEG C that actual measurement gathering line in winter enters the natural gas temperature of gas gathering station.

Calculated from knowledge known in this field: although the inlet temperature of this gas field natural gas generates critical temperature less than hydrate the most, some inlet temperatures are already below the freezing point of water, but due in the gathering line of gas well to gas gathering station with the presence of methanol, therefore will not generate hydrate or ice in the gathering line, pipe fitting of gas well to gas gathering station.But, if it is 10 DEG C that this gas field natural gas enters the temperature of gas gathering station, pressure is 20MPa, if not heating with regard to reducing pressure by regulating flow to 4MPa in gas gathering station, the temperature of natural gas will drop to-47.5 DEG C, the minimum use temperature allowed well below natural gas line, pipe fitting, is not permitted in natural gas production process, system.Therefore, even if the most unblocked from gathering line, the pipe fitting of gas well to gas gathering station, natural gas also must first be heated to uniform temperature in gas gathering station during reducing pressure by regulating flow.Heating then needs to consume substantial amounts of natural gas.

7), although surface throttling oil pipe method can be with existing well head ground insulating method use in conjunction, but owing to existing well head ground insulating method can not increase, improve the natural gas temperature having risen to well head, therefore by existing well head ground insulating method to well head, well site surface gathering and transferring pipeline, buried gathering line, gas gathering station pipeline etc. is incubated, although natural gas can be slowed down at well head, the heat dissipation capacity of gathering line and temperature drop, but can not effectively solve well head, gas hydrates in gathering line or ice blockage problem, more can not solve the gathering line pipe fitting prolonged cold operation problem that natural gas is not added with certainly existing during thermal throttle blood pressure lowering, the heating energy consumption issues before natural gas reducing pressure by regulating flow can not be solved.Therefore when surface throttling oil pipe method utilizes existing well head ground insulating method, it is impossible to solve the defect of the method self.But also the fixed investment of gas gathering and transportation can be significantly increased.

From thermodynamics knowledge: the temperature drop that reducing pressure by regulating flow produces is unrelated with heat loss during throttling, therefore insulation can not solve the temperature drop problem that reducing pressure by regulating flow produces.

From knowledge known in this field: during buried pipeline insulation, general Huang jacket foam thermal insulation of using, costly.

8) although, surface throttling oil pipe method can be with existing wellhead ground tracing thermal-insulating method or heat-exchange method use in conjunction, but owing to most domestic gas well does not has power supply, such as each gas field of Ordos Basin, it is respectively positioned in desert, semidesert environment, does not has industrial power to use.Therefore, although utilizing existing wellhead ground tracing thermal-insulating method or heat-exchange method can increase, improve the natural gas temperature having risen to well head, but because this tracing thermal-insulating method or heat-exchange method just must be had ready conditions in the well site having heating furnace and industrial power enforcement, cannot implement in the well site not having heating furnace and industrial power, and regardless of whether use industrial power to implement, all there is the defect similar with heating furnace heating in this tracing thermal-insulating method or heat-exchange method.Therefore when surface throttling oil pipe method utilizes existing wellhead ground tracing thermal-insulating method, it is impossible to solve the defect of the method self.But also the fixed investment of gas gathering and transportation can be significantly increased.

9) although surface throttling oil pipe method can be with methanol use in conjunction, can effectively prevent or release gas hydrates or ice blocking pit shaft, well head, gathering line pipe fitting problem, but owing to methanol can not heat rising natural gas temperature, the gathering line pipe fitting prolonged cold operation problem that natural gas is not added with certainly existing during thermal throttle blood pressure lowering can not be solved, the heating energy consumption issues before natural gas reducing pressure by regulating flow can not be solved, and methanol has severe toxicity, there is serious environment pollution problem, therefore surface throttling oil pipe method and methanol use in conjunction can not solve the defect of the method self.

From open source information and knowledge known in this field: in alcohols material in addition to methanol, all there is the defects such as price is high, freezing point high (the minimum freezing point of ethylene glycol-68 DEG C), recycling difficulty are big in other alcohols (such as ethylene glycol).Domestic natural gas actual production at present still commonly uses methanol, not other alcohols of large-scale use (such as ethylene glycol).

Open source information shows: in alcohols material, and the price of methanol is minimum.Methanol belongs to poison hazardous chemical inflammable and explosive, huge, and intake arises that toxic reaction more than 4 grams, wrongly takes just can cause more than 10 grams and loses the sight of both eyes, and fatal dose is about 70 milliliters, and methanol steam energy grievous injury eyes are neural.The ability of methanol suppression gas hydrates is far above other alcohols, general by the methanol in rectificating method recovery sewage, reclaims the sewage after methanol typically containing methanol about 0.3%.During domestic natural gas produces at present, it is common to use methanol is as hydrate inhibitor and antifreezing agent.

Open source information shows: with rectificating method or other existing methods reclaim from sewage ethylene glycol, ethanol difficulty relatively big, the response rate is low, and cost recovery is high.

From knowledge known in this field: when using methanol in natural gas produces, a small part methanol will mix with natural gas, during natural gas motorcar, part is burned, part eventually enters into pollution environment in atmospheric environment or ground environment；The methanol also having most enters from natural gas in isolated sewage, forms poison sewage；Although these poison sewages can process by existing method, reclaiming overwhelming majority methanol therein, but still remainder methanol cannot utilize existing method 100% to reclaim completely, or cost recovery is the highest and abandon reclaiming；Although reclaiming the poison sewage after methanol still contain small part methanol, but because it has not had value, natural gas being produced and also there is no value, being ultimately discharged in ground environment or inject underground, severe contamination ground environment or underground environment；Reclaiming methanol and need higher cost recovery, consume mass energy, the poison sewage after reclaiming methanol injects underground and is also required to consume a large amount of electric energy.

10) although existing hydrate inhibitor for natural gas can replace methanol and surface throttling oil pipe method use in conjunction, thus the harm of the method application methanol is eliminated.But owing to existing goods hydrate inhibitor exists or natural gas extraction cost can be significantly increased, or it is toxic, or cannot reclaim, or there is other side effect, or low temperature environment can not effectively solve gas hydrates problem and ice formation issues in the winter time, or gas hydrates problem and ice formation issues can not be effectively solved when natural gas self-temperature is relatively low, or can not effectively solve the different defects such as gas hydrates problem when the pressure of natural gas own is higher, it is impossible to meet natural gas and produce being actually needed of being normally carried out.And hydrate inhibitor for natural gas is the same with methanol, rising natural gas temperature can not be heated, the gathering line pipe fitting prolonged cold operation problem that natural gas is not added with certainly existing during thermal throttle blood pressure lowering can not be solved, it is impossible to solve the heating energy consumption issues before natural gas reducing pressure by regulating flow.Therefore, surface throttling oil pipe method and hydrate inhibitor for natural gas use in conjunction, the defect of the method self can not be solved.

11), patent CN02820253.8 " method reclaiming hydrocarbon from hydrate " discloses one " aqueous solution ", it is possible to replaces methanol to prevent hydrocarbon hydrate from being formed and the water freezing in natural gas, and there is not the defect of methanol.But the document disclosed " aqueous solution " is the same with methanol, the temperature raising natural gas can not be heated, the gathering line pipe fitting prolonged cold operation problem that natural gas is not added with certainly existing during thermal throttle blood pressure lowering can not be solved, it is impossible to solve the heating energy consumption issues before natural gas reducing pressure by regulating flow.Therefore, surface throttling oil pipe method and this " aqueous solution " use in conjunction, the defect of the method self can not be solved.

12), with surface throttling oil pipe method produce natural gas time, need heated natural gas.And heat and need to consume mass energy and natural gas, natural gas energy consumption, cost, fixed investment can be caused to be significantly increased, natural gas production process can be caused to complicate, production management workload is significantly increased.

Calculated from knowledge known in this field: when producing natural gas by surface throttling oil pipe method, the amount of natural gas that heating furnace is consumed is more than the 3% of gas well gas production.Year gas production about 45,000,000,000 mark side, Ordos Basin each gas field, if all producing the amount of natural gas that consumed every year of natural gas, only heating furnace just more than 1,300,000,000 mark sides/year by surface throttling oil pipe method.

From knowledge known in this field: the method for current domestic commonly used ground heating furnace heating promotes natural gas temperature.Domestic there is presently no the example of heat temperature raising natural gas in Wellbore of Gas Wells.

As a example by Soviet Union's Sulige gas field Su10 Block.

The production run data of this block shows: the production technology of Su10 Block is first to be heated up by heated by natural gas with heating furnace in well site, the most just reducing pressure by regulating flow, and utilizes the pipelined of buried yellow jacket polyurethane foam insulation layer insulation to gas gathering station.But, this technique occurs in that many major defects in the application: one is that patrol difficulty is big because this block is located in desert, it is difficult to finds in time, solve heating furnace and stop working problem, and then causes gas well to be difficult to normally producing；Two be the burning line of heating furnace despite tracing thermal-insulating, but still can be condensed out a large amount of aqueous water ice blockage burning line at temperature less than-20 DEG C, and then cause gas-fired heater to stop working；Three are that while gas well mouth tracing thermal-insulating, but below ground pit shaft part is not incubated, and the most generally there is Hydrate Plugging problem when temperature is less than-20 DEG C, cause gas well normally to produce, and can therefore further result in the heating furnace interruption of service；Four is that heating furnace is adjacent with gas well, when when gas well, the emptying of burning line accident or revealing for some reason, it may appear that the severe compromise that gas, fire coexist；Five is that gas well is water produced containing the sour gas such as carbon dioxide, hydrogen sulfide and calcium ions and magnesium ions, to the high pressure coil pipe seriously corroded in heating furnace, can cause high pressure coil pipe serious scale, easily cause serious accident；Six is that heating furnace air consumption is huge；Seven is that gathering line, insulation of equipment expense and heating furnace fixed investment expense are huge, causes natural gas production cost to be significantly increased；Eight is to cause management workload to increase severely because well site adds heating furnace operation.

Two, downhole choke oil pipe method: also known as downhole choke method in oil pipe.The method is that certain depth arranges special throttling arrangement (such as subsurface choke) in pit shaft oil pipe, arranges compressor in gas gathering station, have only with winter production mode, the then employing summer having, two kinds of modes of production in winter；Wherein, production in summer mode is the production method used when annual 5～JIUYUE temperature, ground temperature are higher, which is first to allow the natural gas in underground gas storage layer (abbreviation gas-bearing formation) by this special throttling arrangement (such as subsurface choke) reducing pressure by regulating flow, continue to rise to well head by oil pipe the most again, allow natural gas be delivered to gas gathering station by buried gathering line between well head, well site surface gathering and transferring pipeline, well site to gas gathering station the most again, then allow the compressor entrance defeated operation of subsequent set that the natural gas entering gas gathering station is arranged in crossing (i.e. without) gas gathering station；Winter production mode is annual 1～April, 10～December temperature, the production method used when ground temperature is relatively low, which is first to allow the natural gas in underground gas storage layer (abbreviation gas-bearing formation) by this special throttling arrangement (such as subsurface choke) reducing pressure by regulating flow, continue to rise to well head by oil pipe the most again, natural gas is allowed to pass through well head the most again, well site surface gathering and transferring pipeline, between well site to gas gathering station, buried gathering line is delivered to gas gathering station, then gas pressure is increased in the compressor that the natural gas allowing entrance gas gathering station is arranged in entering gas gathering station, the natural gas after increasing pressure is allowed to enter the defeated operation of subsequent set the most again.There is following defect in the method:

From Soviet Union's Sulige gas field actual production data: this gas field mainly uses downhole choke oil pipe method to produce natural gas, the block wherein having such as Soviet Union 11 blocks are outer employing whole year winter production mode during maintenance.

1) although no longer using heating furnace heated natural gas, no longer allow natural gas in surface throttling blood pressure lowering, but but add fixed investment and the downhole choke plant investment of gas gathering station inner compressor, the especially fixed investment of gas gathering station inner compressor is the hugest, thus cause natural gas production fixed investment, production cost to be significantly increased, cause natural gas production process to complicate.And it is added significantly to natural gas production management workload.

From knowledge known in this field: as a example by Sulige gas field of reviving, the fixed investment of compressor is the several times of heating furnace, the expense building 1 compressor station reaches tens million of unit, need the systems such as the combustion gas of auxiliary construction complexity, generating, water circulation and special Factory Building, management workload is big, and operating maintenance expense is high.And the expenditure of construction of 1 heating furnace only has hundreds of thousands unit, it is not necessary to any aid system, outdoor installation, management is simple.

2) when, using winter production mode, in order to allow rise to well head, enter surface gathering and transferring pipeline natural gas temperature be not less than hydrate critical generation temperature, must first in pit shaft oil pipe by high-pressure natural gas reducing pressure by regulating flow to the lowest pressure, at ground compressor, the pressure of natural gas is improved to desirable pressure defeated outside gas gathering station the most again, thus cause natural gas production cost, energy consumption to be significantly increased；And air consumption is huge.

From knowledge known in this field: in order to ensure the discharge pressure of Gao Long-distance Transmission Pipeline, reducing energy consumption, the natural gas pressure when gas collection produces should not the lowest, also should not be the highest.Such as gas field of pacifying the border region, Soviet Union's Sulige gas field, it is desirable to outside gas gathering station, defeated Stress control is 3～5MPa.

From knowledge: first gas pressure is slatterned by reducing pressure by regulating flow in down-hole oil tube, then with compressor in gas gathering station supercharging, it is clear that be a kind of irrational production method.

As a example by 11 blocks of reviving.

Open source information shows: 11 blocks of reviving are positioned at Ordos, inner Mongolia desert area, and winter minimum temperature reaches-31 DEG C.

The operational data of 11 blocks of reviving shows: this block natural gas well average well depth about 3500 meters, shaft bottom gas-bearing formation temperature about 110 DEG C, general daily output tolerance 1～50,000 mark side/day, part gas well daily output tolerance exceedes less than 10,000 mark sides/day more than 50,000 mark sides/day, part gas well daily output tolerance.Gas well all uses plain tubing, sleeve structure, oil pipe used, sleeve pipe to be metal blank tubing.Gas well mouth, well site surface gathering and transferring pipeline, pipe fitting use felt insulation, and the buried gathering line between well site to gas gathering station is not incubated.The defeated distance of collection (also known as collecting defeated radius) of well site to gas gathering station is 500～ten thousand metres, and the gathering line design buried degree of depth 1.6 meters (freezing 1.5 meters of layer), surveying 1.6 meter layer year-round average temperature is 9 DEG C, and winter minimum temperature is less than 5 DEG C.Actual measurement gas well mouth oil pipe outlet pressure in winter is 0.5～0.7MPa, casing pressure 15～20MPa, and actual measurement well head natural gas temperature in winter is-3～9 DEG C.

The winter production technique that this block uses is: special throttling arrangement (such as the subsurface choke) reducing pressure by regulating flow arranged in first passing through down-hole oil tube from the natural gas of gas-bearing formation is to 0.5～0.7MPa, continue to rise to well head by oil pipe the most again, it is delivered to gas gathering station the most again by buried gathering line between well head, well site surface gathering and transferring pipeline, well site to gas gathering station, to 3～5MPa, the defeated operation of subsequent set is then entered back into subsequently into increase pressure in the compressor that gas gathering station is arranged；Compressor horsepower is generally 500 kilowatts, drives with combustion gas.

From knowledge known in this field calculate: pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 110 DEG C to 0.7MPa time, its temperature will drop to 50 DEG C.

Calculated from knowledge known in this field: pressure is that Soviet Union's Sulige gas field gas hydrates generation critical temperature of 0.7MPa is-5.45 DEG C.

Therefore, after although this block natural gas is by special throttling arrangement (such as the subsurface choke) reducing pressure by regulating flow of setting in down-hole oil tube, until entering in the compressor that gas gathering station is arranged, temperature is above gas hydrates and generates critical temperature, will not form gas hydrates blocking.

But, owing to this block natural gas well mouth pressure only has 0.5～0.7MPa, and outside gas gathering station, defeated pressure typically requires 3～5MPa, needs for this to increase gas pressure with compressor, needs to consume substantial amounts of natural gas.

From knowledge known in this field and Soviet Union's 11 block operational datas: this block does not has industrial power available, 1 power is that the compressor of 500 kilowatts consumes amount of natural gas every day more than 4000 mark sides/day, and the whole total air consumption of block compressor is more than the 3% of this block total gas production.

3) when, using winter production mode, if the gas production of the natural gas well is the lowest, the temperature that natural gas rises to well head after downhole choke is the lowest, still can form Hydrate Plugging pit shaft, well head, gathering line and pipe fitting, thus have a strong impact on natural gas and produce.

As a example by Soviet Union Sulige gas field Soviet Union 6-1 station.

The Soviet Union 6-1 station means of production for many years show: Soviet Union 6-1 station and Soviet Union's 11 blocks belong to Sulige gas field structure of reviving, gas well overview is similar to, administering 23 mouthfuls of natural gas wells, gas well mouth, gathering line are not incubated, and the buried degree of depth of gathering line is at frost line (freezing layer) below；Use the Downhole Choking Technology identical with 11 blocks of reviving；Natural gas well mouth oil pipe outlet pressure is 1～2MPa, and casing pressure is 15～20MPa, wellhead temperature-2～5 DEG C, and gas output per well is 0.3～10,000 mark sides/day.Winter in 2009, there is 18 mouthfuls of wells of Gas well blocking, cumulative effect tolerance 83.58 ten thousand side in Soviet Union 6-1 station.

Being calculated from knowledge known in this field: pressure is the Su Lige natural gas of 1～2MPa, it is-1.2～5.1 DEG C that its hydrate generates critical temperature.Therefore when wellhead temperature is-2 DEG C, inevitable at well head generation hydrate.

As a example by Sulige gas field Fructus Persicae 7-4 gas gathering station of Soviet Union, 20-4 gas gathering station of Soviet Union.

The Fructus Persicae 7-4 gas gathering station means of production for many years show: 9 mouthfuls of natural gas wells on the 6# gas gathering line of Fructus Persicae 7-4 gas gathering station administration belong to, with 11 blocks of reviving, Sulige gas field structure of reviving, gas well overview is similar to, gas well mouth, well site surface gathering and transferring pipeline, pipe fitting use felt insulation, buried gathering line is not incubated, and the buried degree of depth of gathering line is at frost line (freezing layer) below.Use the Downhole Choking Technology identical with 11 blocks of reviving.Natural gas well mouth oil pipe outlet pressure is 1～2MPa, and casing pressure is 15～20MPa, wellhead temperature-2～5.5 DEG C, and gas output per well is 0.3～10,000 mark sides/day.Only 2010 Decembers one month are i.e. accumulative occurs surface line or pit shaft to block 20 times, causes these 9 mouthfuls of wells within 30th, all to close a well in December in 2010, cannot opening well and making production to April in 2011 30 parts.And after surface line or pit shaft block, release blocking with methanol and can not maintain normal production；During Severe blockage, also cannot release blocking with methanol.

20-4 gas gathering station of the Soviet Union means of production for many years show: 4 mouthfuls of natural gas wells on the 1# gas gathering line of 20-4 gas gathering station of Soviet Union administration belong to, with 11 blocks of reviving, Sulige gas field structure of reviving, gas well overview is similar to, gas well mouth, well site surface gathering and transferring pipeline, pipe fitting use felt insulation, buried gathering line is not incubated, and the buried degree of depth of gathering line is at frost line (freezing layer) below.Use the Downhole Choking Technology identical with 11 blocks of reviving.Natural gas well mouth oil pipe outlet pressure is 1～2MPa, and casing pressure is 15～20MPa, wellhead temperature-3～6 DEG C, and gas output per well is 0.3～10,000 mark sides/day.Only 2009 Decembers one month are i.e. accumulative there is surface line or pit shaft frozen block 6 times, causes these 4 mouthfuls of wells until on January 1st, 2010 the most all closes a well in, until on April 30th, 2010 still cannot opening well and making production.And after surface line or pit shaft block, release blocking with methanol and can not maintain normal production；During Severe blockage, also cannot release blocking with methanol.

Being calculated from knowledge known in this field: pressure is the Su Lige natural gas of 1～2MPa, it is-1.2～5.1 DEG C that its hydrate generates critical temperature.Therefore when wellhead temperature is-3 DEG C, inevitable at well head generation hydrate.

4) when, using production in summer mode, although compressor does not runs, but still need higher maintenance cost and administration fee use, thus cause natural gas production cost to increase.

5) when, using production in summer mode, natural gas is after throttling arrangement (such as subsurface choke) reducing pressure by regulating flow special in pit shaft oil pipe, although temperature is the most relatively low, but still could possibly be higher than upper wellbore formation temperature, therefore natural gas continues through during oil pipe flows to well head after reducing pressure by regulating flow, remaining to constantly dispel the heat to stratum, temperature still can constantly decline.When natural gas lift to well head, its temperature may generate critical temperature already below hydrate, thus forms Hydrate Plugging upper wellbore, causes gas well normally to produce.

From knowledge: most domestic area belongs to the normal system of ground temperature, and each gas field is no exception.In such system, often increasing by 100 meters to the degree of depth of underground, ground temperature about increases by 3 degree.The formation temperature on 100 meters of ground of distance is about 7 degree, the formation temperature on 200 meters of ground of distance is about 10 degree, the formation temperature on 300 meters of ground of distance is about 13, the formation temperature on 400 meters of ground of distance is about 16, the formation temperature on 500 meters of ground of distance is about 19 degree, the formation temperature about 34 degree on 1000 meters of ground of distance, the formation temperature about 64 degree on 2000 meters of ground of distance, by that analogy.

From knowledge known in this field: the temperature drop that reducing pressure by regulating flow produces is to carry out in down-hole or carry out on ground unrelated with throttling.

Calculated from knowledge known in this field: as a example by Sulige gas field of reviving, average 3500 meters of this gas field well depth, the temperature of shaft bottom natural gas about 110 DEG C, pressure is up to 20MPa, if using production in summer mode the most not use compressor boost, because the outer defeated pressure requirements of gas gathering station is 3～5MPa, the gas pressure after downhole choke necessarily be greater than 3～5MPa.When natural gas by be arranged on bottommost in oil well oil conduit (according to be arranged at 3500 meters calculate) special throttling arrangement (such as subsurface choke) by 20MPa reducing pressure by regulating flow to 4MPa after, natural gas temperature will drop to 73 DEG C.Therefore, natural gas is above hydrate in the temperature before and after pit shaft oil pipe reducing pressure by regulating flow and generates critical temperature, will not produce the special throttling arrangement of Hydrate Plugging (such as subsurface choke) and oil pipe.

From knowledge known in this field: in Wellbore of Gas Wells, when natural gas temperature is higher than the earth temperature, natural gas can pass through the annular space-casing wall-cementing concrete hoop the earth heat radiation of tubing wall-casing tube composition.The oil pipe, the sleeve pipe that use in domestic current gas well are metal blank tubing.

Being calculated from knowledge known in this field: as a example by Sulige gas field of reviving, if the natural gas temperature after reducing pressure by regulating flow is 73 DEG C, already above the earth temperature on less than 2000 meters of ground, therefore the natural gas oil pipe from less than 2000 meters of ground just has begun to dispel the heat to stratum.Thus calculate further and understand, if gas well gas production is less than 10,000 mark sides/day, after reducing pressure by regulating flow, temperature is that the natural gas of 73 DEG C is when continuing to rise to well head by oil pipe, its temperature will be less than 10 DEG C, generate critical temperature 10.7 DEG C already below hydrate during its 4MPa, inevitable on oil pipe top, well head form Hydrate Plugging.

As a example by 11 block Soviet Union 11-48-59 wells of reviving.

When this well uses downhole choke oil pipe method production in summer, pit shaft oil pipe top frequent jams, i.e. in oil pipe, add methanol de-plugging from well head after blocking, it is sometimes desirable to repeatedly could release blocking 2～4 times every time.To this end, this well is taked to be spaced the method periodically adding 50 liters of methanol in pit shaft oil pipe 1 day, to ensure that gas well normally produces.Survey this well casing pressure (suitable with pressure before reducing pressure by regulating flow at the bottom of the natural gas well) 18.8MPa, oil pressure (well mouth oil pipe outlet pressure) 4MPa, instantaneous gas production 500m on August 20th, 2010³/ h (is equivalent to produce tolerance 11000m daily³/ h), wellhead temperature 9.8 DEG C.

Being calculated from knowledge known in this field: Soviet Union's Sulige gas field gas hydrates critical generation temperature about 10.7 DEG C of pressure 4MPa, therefore wellhead temperature is that the natural gas of 9.8 DEG C necessarily forms Hydrate Plugging.

Therefore, if this well will be unable to normally produce as hydrate braking measure without methanol.

6), equally, when using production in summer mode, owing to natural gas is unrelated with reducing pressure by regulating flow at heat radiation, the temperature drop of buried gathering line, after the natural gas of reducing pressure by regulating flow enters buried gathering line in down-hole oil tube the most, equally exist temperature and reduce problem.After its temperature is down to gas hydrates generation critical temperature, Hydrate Plugging gathering line, pipe fitting can be generated equally.

7) although after well head, gathering line pipe fitting being incubated with existing heat preserving method, it is possible to effectively prevent natural gas from significantly lowering the temperature at well head, gathering line, but gathering line fixed investment to be significantly increased.And owing to existing heat preserving method can not provide heat to natural gas, the most existing heat preserving method can not solve the natural gas wellhead temperature problem already below hydrate-formation temperature.

8), due to be arranged on the special throttling arrangement (such as subsurface choke) within pit shaft oil pipe cannot be carried out regulation, after therefore this device once installed by gas well, be difficult to adjust gas well yield again, thus to gas well management bring great difficulty.

From knowledge known in this field: during gas well liquid loading, the gas reservoir factor such as gas-bearing formation pressure, permeability can constantly change, the gas well that especially gas production is high, gas reservoir factor change is the most violent, therefore should adjust natural gas well gas production according to dynamic analysis of gas well in time, this is that gas well management is extremely important and be regular work.When using surface throttling method, by changing the throttling oil nozzle of different pore size or adjusting special throttle valve opening, just can adjust gas well gas production, only a few minutes used time easily by adjusting gas well oil pipe outlet pressure.But when using down-hole oil tube internal restriction method, gas well gas production can only be adjusted by changing the special throttling arrangement (such as subsurface choke) of the internal different pore size of oil pipe, and change special throttling arrangement (such as subsurface choke) every time and all must be replaced with special downhole operation equipment, required expense is the hugest, and time-consuming longer.Therefore, being provided with the gas well of the special throttling arrangement in down-hole in oil pipe, general being difficult to adjusts gas well yield, thus brings great difficulty to production management.

9) it is arranged on inside pit shaft oil pipe due to special throttling arrangement (such as subsurface choke), make existing downhole tool, equipment, instrument cannot pass through again at the bottom of oil pipe lower going-into-well, thus cause great difficulty to the maintenance of various gas wells, detection and underground work, measure etc., cannot implement the most at all.

From knowledge known in this field: the underground work measure such as gas well needs often to carry out to log well, sand surfing, also need to when aerogenesis is abnormal carry out various stimulation work measure.But if down-hole oil tube is provided with downhole choke device, it is difficult to carry out again such underground work, thus has a strong impact on gas well liquid loading.

10), when the pipe aperture in gas well is less, it is difficult to arrange special throttling arrangement (such as subsurface choke), when therefore gas well uses pipe with small pipe diameter oil pipe to produce, is difficult to application the method.

From knowledge known in this field: in order to reduce the operating cost arranging, changing special throttling arrangement (such as subsurface choke) in oil pipe, such device is generally configured to throw in salvaging type (or oil pipe is built-in), directly throw in oil inlet pipe from well head, it is fixed in oil pipe by existing method again and specifies position, and salvage changing or recycling existing method when being no longer necessary to.If tubing diameter is less than 30mm, this special throttling arrangement (such as subsurface choke) is difficult to be manufactured into input salvaging type, the most domestic does not the most produce that to can be used in diameter available less than the special throttling arrangement (such as subsurface choke) of 30mm oil pipe.Domestic there is presently no gas well application the special throttling arrangement of non-releasing type (such as subsurface choke) open source information and precedent.

From knowledge known in this field: producing natural gas with the less oil pipe of internal diameter is a kind of ripe production method, aquifer yield is high, take liquid take the gas well of outlet capacity difference through frequently with.

11), when producing by the method, if possessing generation hydrate condition in Wellbore of Gas Wells, well head, gathering line, pipe fitting, the method suppression hydrate being added thereto to methanol is generally taked to generate or release blocking.Therefore there is the methanol applied defect similar with " ground oil conduit flow limit method " in the method.

12), owing to the throttle orifice of special throttling arrangement (such as subsurface choke) only has 1～3mm, Wellbore of Gas Wells draining difficulty can be caused, easily cause Wellbore of Gas Wells hydrops, make gas well normally to produce.

From knowledge known in this field: as a example by DaNiuDi gas field, Soviet Union's Sulige gas field, special throttling arrangement (such as the subsurface choke) throttle diameter in this gas field is generally 1～3mm, major part Gas well dewatering amount is more than 0.5 ton per day, and some blocks such as Hangjin Banner block water yield of well is more than 10 ton per days；These water are typically in a liquid state water (free water) bottom gas well, need to rely on carrying of natural gas just can rise to well head；When natural gas is by throttle orifice, pressure declines, and temperature is greatly reduced, and part vapourous water can be converted into aqueous water, takes outlet capacity and also can decline, and necessarily causes Wellbore of Gas Wells water accumulating volume to be significantly increased；Static pressure produced by pit shaft hydrops can seriously hinder natural gas to rise to well head, and when the static pressure that hydrops produces is more than or equal to the pressure after natural gas throttling, natural gas cannot rise to well head again, thus cause gas well to produce.

13), owing to the throttle orifice of special throttling arrangement (such as subsurface choke) only has 1～3mm, when gas well goes out sand and when forming corrosion solid content (such as Iron sulfuret .), understand Severe blockage throttle orifice, cause gas well to produce.

From knowledge known in this field: as a example by Sulige gas field of reviving, this gas field gas-bearing formation could produce after being required to fracturing sand feeding, and added quartz sand particle size major part is 0.5～3mm；When gas well liquid loading, these quartz sand grains are usually entrained in pit shaft (this area is commonly called as out sand) by air-flow from gas-bearing formation, after these sand grains enter throttle orifice, and meeting Severe blockage throttle orifice, gas well is caused normally to produce, it has to salvage throttling arrangement to ground cleaning process.

From knowledge known in this field: the gas field having such as Sebei Gas Field, gas-bearing formation loosens, and goes out husky serious；The most general smooth gas field, some gas fields, gas field of pacifying the border region are containing a large amount of hydrogen sulfide, carbon dioxide, the corrosion products such as Iron sulfuret. just can be formed entering special throttling arrangement (such as subsurface choke), and such corrosion product belongs to unformed solid content, the grains of sand can be adhered to, therefore, it is possible to Severe blockage throttle orifice, gas well is caused normally to produce.

Three, surface throttling tiretube process: the method is to allow natural gas rise to well head by gas well sleeve pipe or oil sets annular space, subsequently into surface gathering system reducing pressure by regulating flow.There is following defect in the method:

1), this is a kind of improper production method, it is a kind of accident treatment flow process when oil pipe or sleeve pipe break down or when oil pipe can not use in a short time or interim production method, gas well is long-term, there is all drawbacks with the method production on a large scale, is not permitted in natural gas production process, rules and regulations.

Understood by knowledge known in this field: gas well down-hole pit shaft is made up of oil pipe and sleeve pipe, sleeve pipe is in outside, cementing concrete (being commonly called as cement sheath) outside by tube wall combines with stratum, oil pipe is arranged on cannula center, internal surface of sleeve pipe and oil-pipe external wall composition annular space (abbreviation oil sets annular space).When oil pipe can not use, the natural gas in shaft bottom can be allowed to rise to well head by oil sets annular space, subsequently into surface line.When sleeve pipe occurs in that damage (such as deformation), it is impossible in again oil pipe being arranged at sleeve pipe and when forming oil sets annular space with sleeve pipe, oil pipe can also be entered down in gas well sleeve pipe, directly allow natural gas rise to well head in sleeve pipe.Due to sleeve pipe major function be protection gas well overall structure and oil pipe composition oil sets annular space for underground work rather than for being directly produced natural gas, the most direct sleeve pipe or directly belong to improper production method with oil sets annular space production natural gas.

2) the method needs also exist in surface throttling blood pressure lowering, and before reducing pressure by regulating flow, the most necessary first heated natural gas, therefore exists the defect similar with " surface throttling oil pipe method ".

Four, downhole choke tiretube process: the method is that certain depth arranges special throttling arrangement (such as subsurface choke) in gas well sleeve pipe or oil sets annular space, after allowing natural gas by this special throttling arrangement (such as subsurface choke) blood pressure lowering, continue to rise to well head by sleeve pipe or oil sets annular space again, subsequently into surface gathering and transferring pipeline reducing pressure by regulating flow.There is following defect in the method:

1), the method belongs to a kind of method in theory with feasibility, the most domestic precedent also not having actual application the method.

2), owing to arranging the difficulty of special throttling arrangement (such as subsurface choke) in sleeve pipe or in oil sets annular space far above setting in oil pipe, and special throttling arrangement (such as the subsurface choke) manufacture difficulty in the sleeve pipe or in oil sets annular space is far above special throttling arrangement (such as subsurface choke) used by oil pipe, the most domestic the most do not produce that to can be used in the special throttling arrangement (such as subsurface choke) of sleeve pipe or oil sets annular space available.

3), the method is equally in downhole choke blood pressure lowering, the defect that therefore existence is similar with downhole choke oil pipe method.

Five, surface throttling coiled tubing method: the method is first to replace the oil pipe in Wellbore of Gas Wells sleeve pipe with coiled tubing, then allow the natural gas in underground gas storage layer (abbreviation gas-bearing formation) rise to well head by the coiled tubing in Wellbore of Gas Wells sleeve pipe, then enter back in the gathering line similar with " surface throttling oil pipe method ".The defect of the method is: there is the defect similar with " ground oil conduit method ".

Six, downhole choke coiled tubing method: the method is first to replace the oil pipe in gas well sleeve pipe with coiled tubing, and certain depth arranges special throttling arrangement (such as subsurface choke) in coiled tubing, compressor is set in gas gathering station, then allow the natural gas in underground gas storage layer (abbreviation gas-bearing formation) by this special throttling arrangement (such as subsurface choke) reducing pressure by regulating flow, continue to rise to well head by coiled tubing the most again, then enter back in the gathering line similar with " downhole choke oil pipe method ", produce according to the mode of production similar with " downhole choke oil pipe method ".There is following defect in the method:

1), there is the defect similar with " downhole choke oil pipe method ".

2), owing to arranging the difficulty of special throttling arrangement (such as subsurface choke) in coiled tubing far above setting in oil pipe, and special throttling arrangement (such as the subsurface choke) manufacture difficulty in the coiled tubing is far above special throttling arrangement (such as subsurface choke) used by oil pipe, the most domestic the most do not produce that to can be used in the special throttling arrangement (such as subsurface choke) of coiled tubing available.

" natural gas exploiting method of a kind of cleaning " of Application No. 200910143671.2 discloses a kind of natural gas exploiting method, it is possible to produce for natural gas.But the method for this disclosure of the invention is without reference to gathering line pipe fitting minimum use temperature problem, the gathering line pipe fitting prolonged cold operation problem that natural gas is not added with certainly existing during thermal throttle blood pressure lowering can not be solved, the heating energy consumption issues before natural gas reducing pressure by regulating flow can not be solved, the most do not indicate how to solve such problem, the concrete technical scheme solving such problem is not provided.

In a word, above-mentioned natural gas production method, all there is different defects.

Summary of the invention

In the present invention, " natural gas " refers to: flow into the natural gas of gas well, or the fuel gas from stratum extraction from gas-bearing reservoir, including the natural-gas being decomposed to form by underground gas hydrates (such as combustible ice)；The appellation of natural gas is numerous, as from the natural gas of gas field output reservoir gas, from the natural gas of oil field output casing-head gas (also referred to as associated gas), from the natural gas of coal seam output coal bed gas, coal-formed gas, be shale gas from shale extraction；Being characterized mainly in that of " natural gas " in the present invention: be the natural hydro carbons contained in subsurface formations and the mixture of non-hydrocarbon gases.In the present invention, " natural gas " can contain a small amount of water, steam, liquid hydrocarbon.In the present invention, " natural gas " may also mean that the natural non-hydrocarbon gases from stratum extraction, such as the carbon dioxide of carbon dioxide gas well output.

" gas-bearing reservoir " in the present invention refers to: natural contain the stratum having natural gas, and this area is called for short gas-bearing formation or stratum sometimes.

" natural gas production " in the present invention, " production natural gas ": be primarily referred to as natural gas from gas well shaft bottom to the production process leaving gas gathering station, it is also possible to refer to natural gas from gas well shaft bottom to the production process leaving natural gas purification processing factory；Both may refer to gas production produce, it is also possible to refer to gathering production.

" gas production production " in the present invention: be called for short gas production.Refer to the natural gas production technology from gas well shaft bottom to well head or production process.

" gathering production " in the present invention: be called for short and collect defeated or gas gathering and transportation.It is primarily referred to as natural gas and leaves production technology or the production process of gas gathering station from gas well mouth to natural gas；May also mean that natural gas leaves production technology or the production process of natural gas purification processing factory from gas well mouth to natural gas.

" gas gathering station " basic feature in the present invention is: measure the natural gas from gas well, the website of the basic production such as gas-liquid separation management, such as station, north 13, No. 15 stations, north of Changqing oilfields gas production one factory, Soviet Union Sulige gas field Soviet Union 10, No. 1 gas gathering station of 11 blocks of reviving, No. 2 gas gathering stations；Gas gathering station specifically produce function (or process links) because concrete technology design and different, some gas gathering stations such as north 13 station, station, north 15 have heating, reducing pressure by regulating flow, gas-liquid separation, dewfall point (or dehydration) link (or operation), but do not have compressor boost link；Some gas gathering stations such as No. 1 gas gathering station of 11 blocks of Soviet Union, No. 2 gas gathering stations do not heat, reducing pressure by regulating flow, dewfall point (or dehydration) link, but have compressor boost link.

" accumulating " in the present invention refers to: natural gas from leaving oil gas field or natural gas purification processing factory to user use before process.

" gathering line " in the present invention: refer to gas gathering line or the gas gathering line containing a small amount of profit, be primarily referred to as the natural gas line from gas well mouth to gas gathering station, sometimes referred to as pipeline between station；Can be single well pipeline, it is also possible to be 2 mouthfuls of above shared pipelines of well (such as more than 2 mouthfuls of wells series connection and/or natural gas lines in parallel)；Underground can be embedded in, it is also possible to outdoor be laid on ground.

" pipeline between standing " in the present invention refers to: the natural gas line of gas gathering station to natural gas purification processing inter-plant.

" natural gas purification processing factory " in the present invention: be called for short purification plant or treatment plant, be natural gas leave gas field, enter long distance gas pipeline engineering (pipeline) front natural gas is purified, the large-scale station of the integrated treatment such as dewfall point (also known as dehydration).Such as Sulige gas field the first treatment plant, the second treatment plant etc. of reviving.

" oil pipe " in the present invention: i.e. plain tubing, is also called blank tubing or metal blank tubing, is metal material pipe；Refer to that specification limit is engineering diameter × wall thickness=8～1240mm × 1～the oil pipe of 200mm, it is generally divided into non-upset tubing (NU), external upset tubing (EU), IJTBG (IJ), including Large Diameter Pipeline oil pipe, middle caliber oil pipe, several big class of pipe with small pipe diameter oil pipe.In the present invention, the basic feature of " oil pipe " is that metal tube outer wall is not specifically used to the heat-insulation layer of insulation, heat insulation layer, thermal insulation layer, the most not there is the insulation of incubation and thermal insulation function, thermal insulation, heat insulation structural (i.e. metal tube outer wall does not have the structure being effectively increased thermal resistance in subsurface environment), steel pipe as described in " SYT6194-2003-industrial gas oil Oil/gas Well sleeve pipe or oil pipe steel pipe "." oil pipe " in the present invention also includes that inwall has the oil pipe of undercoating (internal coating tubing as oil well paraffin prevention).In the present invention, another key character of " oil pipe " is that one end has pipe screw thread, the other end has pipe hoop structure." oil pipe " in the present invention can also be the metal pipe that two ends have other existing type screw connection structures (as screw nut attachment structure, pipe screw thread are directly connected to structure).

" metal pipe " in the present invention: be that vial outer wall does not has special heat-insulation layer, heat insulation layer, thermal insulation layer or do not has insulation, thermal insulation, the metal tube of heat insulating function structure.

From knowledge known in this field and open source information: oil pipe used by current domestic gas well belongs to metal pipe, although some oil pipes are through basic preservative treatment, but the most not through special insulation, process adiabatic, heat insulation, all there is no special heat-insulation layer, heat insulation layer, thermal insulation layer, the most not there is insulation, thermal insulation, heat insulating function structure.Oil pipe material can be carbon steel, it is also possible to be steel alloy, rustless steel or other metal materials.Oil pipe used by current domestic gas well does not has non-metallic material.

" gas well " in the present invention: be the abbreviation of the natural gas well.

" pit shaft " in the present invention: refer to gas well below ground part, similar with structure of oil well, generally comprise sleeve pipe, oil pipe two large divisions；Wherein, sleeve portion generally comprises surface pipe (being called for short table set), protective casing (being called for short skill set), gas-bearing formation sleeve pipe (abbreviation sleeve pipe), and " pit shaft " sleeve portion having does not has protective casing；Wherein, oil pipe is arranged in sleeve pipe, and oil-pipe external wall and internal surface of sleeve pipe can form annular space (abbreviation oil sets annular space), this annular space can with packer packing every；Oil pipe in " pit shaft " that have connects flow string, completion tubular column, downhole tool, packer, horn mouth etc., and the oil pipe in " pit shaft " that have only connects horn mouth；Oil pipe connecting length (degree of depth) in " pit shaft " is relevant with the buried depth of gas-bearing formation, oil pipe connecting length (degree of depth) in " pit shaft " that have exceedes 5000m, and the oil pipe connecting length (degree of depth) in " pit shaft " that have only has hundreds of rice.

" sleeve pipe " in the present invention: also known as gas-bearing formation sleeve pipe, it is possible to put into oil pipe.The cement sheath that sleeve outer wall is typically formed by cement connects together with stratum, and some sleeve outer walls directly can contact (being less than the gas well sleeve pipe on ground as cement returns height) with stratum.Telescopic joint length (degree of depth) in " pit shaft " is relevant with the buried depth of gas-bearing formation, telescopic joint length (degree of depth) in " pit shaft " that have exceedes 5000m, and the telescopic joint length (degree of depth) in " pit shaft " that have only has hundreds of rice.

" well site " in the present invention: refer to the place, special ground being positioned at around gas well, it is typically provided with well head, surface line, pipe fitting, buried pipeline, some well sites are additionally provided with special valve group (such as choke valve group), heating furnace etc., some well sites only have 1 implication well, and there are 2 mouthfuls or more than 2 mouthfuls gas wells in some well sites.

" well head " in the present invention: also known as christmas tree or production tree, refer to the part that gas well bassets, be typically provided with the pipe fittings such as special valve and oil pipe, cannula exit.

" oil pipe outlet pressure " in the present invention: be called for short oil pressure, refer to the pressure that on christmas tree, tubing gauge shows, expression be natural gas from gas well oil pipe out time pressure.

" casing pressure " in the present invention: be called for short casing pressure, refer to the pressure that on christmas tree, casing pressure table shows, because natural gas density, static pressure are the lowest, when gas well sleeve pipe is without hydrops, casing pressure is more or less the same with the gas pressure in gas well shaft bottom.

" wellhead temperature " in the present invention: refer to the natural gas temperature in christmas tree oil pipe exit, expression is natural gas temperature when rising to well head from gas well shaft bottom.

" heat-insulation layer " in the present invention: also known as heat insulation layer or thermal insulation layer；" insulation " in the present invention is also referred to as adiabatic or heat insulation.

" free water " in the present invention: also known as aqueous water, refer to the water in liquid condition, it is also possible to refer to the water in liquid condition and the mixture of the hydrocarbon (as gas well produces condensate) in liquid condition.

" restricting element " in the present invention: refer to effectively to reduce the specific purpose tool of gas pressure, equipment, pipe fitting, machine components etc. any one, may refer to private section fluid element (such as oil nozzle, special choke valve), it is also possible to refer to effectively reduce the restricting element (such as needle valve, reducer pipe, orifice plate) of gas pressure.

" insulated tubing " in the present invention includes that pipe outer wall (or outside) has any one or two or more compound tube combined of the oil pipe of heat-insulation layer, coiled tubing, hollow rod, specialty metal pipe, special nonmetal pipe, or refers to have any one or two or more compound tube combined of insulation, thermal insulation, the oil pipe of heat insulation structural (or function), coiled tubing, specialty metal pipe, special nonmetal pipe.Further, " insulated tubing " in the present invention can also be special nonmetal pipe.Heretofore described " insulated tubing " can be commodity, it is also possible to makes by existing method；Heretofore described " insulated tubing " inwall can have undercoating (such as nature of glass undercoating, pottery undercoating, organic undercoating etc.), it is also possible to does not has undercoating.

There is inner via hole at " hollow rod " center of referring in the present invention, it is possible to by the sucker rod of fluid, can be any one or two or more combined hollow sucker rod combined of single hole hollow rod, the concentric sucker rod of diplopore, diplopore Factor of Eccentric Rod；Can be the hollow rod of metal material, it is also possible to be the hollow rod of the non-metallic material such as fiberglass, carbon fiber." hollow rod " of the present invention can be commodity, it is also possible to makes by existing method.

" specialty metal pipe " in the present invention: be the vial two ends metal tubes with any non-threaded mechanical connecting structure, as pipe two ends have in flange connection, clamp connection structure, connecting structure for quick coupling any one or the metal tube of two kinds of mechanical connecting structure, its basic feature is to be securely attached to together by two metal tubes." specialty metal pipe " of the present invention can be commodity, it is also possible to makes by existing method.

" special nonmetal pipe " in the present invention is the non-metallic pipe that vial two ends have existing machinery attachment structure, and length can be suitable with oil pipe or coiled tubing, it is also possible to up to hundreds of rice；Described existing machinery attachment structure can be any one or two kinds of the existing mechanical connecting structure of current non-metallic pipe, as screw nut attachment structure, pipe screw thread pipe collar attachment structure, pipe screw thread are directly connected to structure, flange connection, clamp connection structure, connecting structure for quick coupling etc., its basic feature is can be securely attached to together by two non-metallic pipes or by a metal tube, a non-metallic pipe." special nonmetal pipe " of the present invention can be commodity, it is also possible to makes by existing method.

" antifreezing agent " in the present invention: refer to press down ice agent liquid (or pressing down ice agent) or the prevention and control agent aqueous solution (or prevention and control agent) described in " a kind of aid for preventing and controlling natural gas hydrate " file that Chinese Patent Application No. is 2010102562861 described in " natural gas exploiting method of a kind of cleaning " file that Chinese Patent Application No. is 2009101436712, it is also possible to refer to alcohols material (such as methanol, ethanol, ethylene glycol) or existing goods antifreezing agent.

" commodity " in the present invention: refer to the existing product commercially can buied.

The technical problem to be solved in the present invention is to provide a kind of natural gas production method.This production method can make full use of natural energy in natural gas produces and produce natural gas, the wellhead temperature of the natural gas well can be greatly improved, can effectively solve the problem that hydrate affects the problem that natural gas produces, be capable of natural gas do not heat, not supercharging production technology, heating furnace heating, the defeated link of compressor boost collection can be cancelled, can significantly simplify natural gas production process, it is possible to be greatly reduced natural gas produce fixed investment, production cost, energy consumption, from air consumption, management workload etc.；There is enforcement easily, safe and reliable, it is widely used, promotes the excellent features such as easy.

For solving above-mentioned technical problem, one natural gas production method of the present invention, comprise the steps:

1), insulated tubing is put in Wellbore of Gas Wells sleeve pipe or in oil pipe.

2), natural gas is allowed to rise to well head by insulated tubing.

Described insulated tubing should be able to allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate or/and natural gas can be allowed to rely on own temperature temperature after well head or well site reducing pressure by regulating flow to be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C, should be able to put in Wellbore of Gas Wells sleeve pipe or in oil pipe by existing method, gas well liquid loading requirement and regulation should be met；As those of ordinary skill in the art, the particular type of described insulated tubing is can determine by existing method, structure, physical dimension, material, service life, make technique, can determine the particular type of described insulated tubing outer wall (or outside) heat-insulation layer, structure, physical dimension, material, maximum gauge, minimum thickness, heat conductivity, make technique, can determine that described insulated tubing is incubated, adiabatic, the concrete form of heat insulation structural, type, physical dimension, material, heat conductivity, make technique, can determine that the particular number in Wellbore of Gas Wells sleeve pipe or in oil pipe put into by described insulated tubing, length (or degree of depth), position.

Described reducing pressure by regulating flow should be able to reduce natural gas and produce, collects delivery of energy consumption and cost, should be able to meet requirement and the regulation of gas gathering and transportation；As those of ordinary skill in the art, the concrete scheme of described reducing pressure by regulating flow, mode, Restriction Parameters, restricting element is can determine, it is possible to determine natural gas maximum temperature after described well head or well site reducing pressure by regulating flow, minimum temperature, optimum temperature, maximum pressure, minimum pressure, optimum pressure by existing method.

From knowledge known in this field and open source information: the gas pressure transporting to natural gas purification processing factory outside gas gathering station should not be the lowest, the lowest compressor boost is needed to consume energy, the highest easy formation Hydrate Plugging pipeline.

Open source information shows: specification limit is that the oil pipe of engineering diameter × wall thickness=8～1240mm × 1～200mm is used equally to gas well liquid loading；Oil pipe for gas well liquid loading divides long oil pipe and short oil pipe (also known as pipe nipple), and general long tubing length is up to 9～12 meters, and short oil pipe (also known as pipe nipple) length is smaller than 0.5 meter；The oil pipe putting into gas well sleeve pipe typically connects with pipe screw thread, pipe collar, it is also possible to be directly connected to the downhole tool etc. with screw thread-like structure；Tubing length (degree of depth) in gas well sleeve pipe is relevant with gas well well depth, gas-bearing formation buried depth etc., can be up to (as deep as) thousands of rice, it is also possible to up to (as deep as) hundreds of rice.

Open source information shows: heat-insulation layer, heat insulation layer, thermal insulation layer are respectively provided with similar heat insulation function, it is possible to is effectively increased thermal resistance, reduces heat output and heat loss；Its concrete structure, material are varied, the insulation construction (such as glass fibre reinforced plastic insulation layer) of existing single material, also have the insulation construction (such as coating+glass fibre reinforced plastic composite heat-insulating layer) that various material is composited；Both can make with the material that heat conductivity is the lowest, it is also possible to make (such as vacuum heat insulation tube) by the method forming extraordinary vacuum structure；Both may utilize single heat conduction principle and made (such as rubber heat-insulation layer), it is also possible to utilize radiation, heat conduction, each principle of heat transfer to make (such as coating+aluminium foil+rubber heat-insulation layer)；Low thermal conductivity material used can be organic material, it is also possible to be inorganic material, it is also possible to be organic and inorganic material mixing.

Open source information shows: at home in oil well production, for wax control, scribbles the anti-paraffin coating of organic matter or inanimate matter in oil pipe used by some oil wells.

Open source information shows: during steam oil production produces at home, it is common to use commodity instlated tubular replaces plain tubing steam injection, to reduce steam heat loss in pit shaft and heat output.

Open source information shows: any specification oil pipe that specification limit is engineering diameter × wall thickness=8～1240mm × 1～200mm can be made insulated tubing of the present invention by existing method, as at 2.5 inches of plain tubing (external diameter 89mm, internal diameter 76mm) outer wall parcel 10mm heavy sheet glass steel heat-insulation layer can be made into the insulated tubing that external diameter is 109mm, the insulated tubing that external diameter is 55mm is can be made at external diameter 45mm plain tubing outer wall parcel 5mm heavy sheet glass steel heat-insulation layer, at external diameter 73mm, internal diameter 62mm plain tubing outer wall parcel 0.5mm thickness heat insulating coatings and 10mm heavy sheet glass steel composite heat-insulating layer can be made into the insulated tubing that external diameter is 94mm, etc..Therefore, the external diameter insulated tubing that existing pipe aperture is less than in Wellbore of Gas Wells sleeve pipe can be made by existing method.

From open source information and knowledge known in this field: newly-built gas well completion (or building up) is front, gas well only has sleeve pipe, there is no oil pipe.The gas well built up includes existing producing well, stopping production gas well etc., all has in sleeve pipe and sleeve pipe and typically has oil pipe, only do not have oil pipe in only a few improper Wellbore of Gas Wells sleeve pipe in Wellbore of Gas Wells.In Wellbore of Gas Wells, oil pipe is positioned in sleeve pipe and forms annular space with sleeve pipe, can with one heart can also be eccentric, therefore the oil pipe caliber in Wellbore of Gas Wells is less than sleeve pipe caliber.Underground work is the mature technology that natural gas produces, domestic generally by the method for underground work, oil pipe put into gas well sleeve pipe or oil pipe is taken out from gas well sleeve pipe, the most generally by the method for underground work, hollow rod or coiled tubing put into gas well oil pipe or it is taken out from gas well oil pipe.Therefore, it also is able to put into the existing oil pipe of gas well less than the oil pipe of the existing oil pipe caliber of gas well or it taken out from the existing oil pipe of gas well by the method for underground work.

From open source information and knowledge known in this field: external diameter can be less than the insulated tubing of casing inner diameter used by gas well by the method for underground work and put into as plain tubing in gas well sleeve pipe or be taken out, replace the plain tubing that gas well is presently used；It also is able to, by the method for underground work, external diameter is less than the insulated tubing of pipe aperture used by gas well put into oil pipe used by gas well or be taken out.As Sulige gas field of reviving, sleeve pipe used by the gas well of gas field of pacifying the border region are generally 7 inches of sleeve pipe (external diameter 173mm, internal diameter is more than 150mm), oil pipe used is generally 2.5 inches of plain tubings (external diameter 89mm, internal diameter 76mm) or external diameter 73mm, internal diameter 62mm plain tubing；External diameter is that the insulated tubing of 110mm is less than 7 inches of more than casing inner diameter 40mm, can put in 7 inches of sleeve pipes；External diameter is that the insulated tubing of 55mm is less than 2.5 inches of plain tubing internal diameter 21mm, can put in 2.5 inches of plain tubings；Therefore, insulated tubing of the present invention can be put in gas well sleeve pipe or oil pipe by the method for underground work.

From knowledge known in this field: owing to by pit shaft inner sleeve space, internal diameter is limited and pit shaft bending, gradient affect, the maximum outside diameter of insulated tubing is preferably less than Wellbore of Gas Wells middle sleeve internal diameter more than 5 millimeters, and otherwise insulated tubing may be stuck in certain position of sleeve pipe during putting into sleeve pipe and cause down-hole accident；Limiting due to subsurface environment and temperature restricts, down-hole oil tube typically should not use polyurethane+polyethylene from high pressure process shell (such as the yellow jacket) compound insulation structure that buried pipeline is often applied；Falling into shaft bottom due to junk and can bring a lot of trouble, severe patient can cause down-hole accident, and therefore the heat-insulation layer of down-hole oil tube outer wall should not be bundled in the method for tube wall with the heat insulation prefabricated block that surface line is conventional and makes.Therefore, as those of ordinary skill in the art, can determine the particular type of described insulated tubing, structure, physical dimension, material, service life, make technique, can determine the particular type of described insulated tubing outer wall (or outside) heat-insulation layer, structure, physical dimension, material, maximum gauge, minimum thickness, heat conductivity, make technique, can determine that described insulated tubing is incubated, adiabatic, the concrete form of heat insulation structural, type, physical dimension, material, heat conductivity, make technique, can determine that the particular number in Wellbore of Gas Wells sleeve pipe or in oil pipe put into by described insulated tubing, length (or degree of depth), position.

From knowledge known in this field: can make at oil-pipe external wall by existing method and meet the heat-insulation layer of gas well liquid loading requirement and regulation, it is possible to make by existing method meet gas well liquid loading requirement and regulation there is insulation, thermal insulation, the oil pipe of heat insulation structural (or function).Liaohe Oil Field, in height solidifying oil oil well production, in order to reduce crude oil heat loss in oil pipe and temperature drop, keeps crude oil temperature in oil pipe, and the oil pipe that outer wall 5mm heavy sheet glass steel is incubated was applied in once large-scale experiment.Commodity instlated tubular commonly used in current domestic steam oil production typically has vacuum heat-preserving heat insulating construction.

From knowledge known in this field and open source information: the oil pipe used in domestic gas well is metal blank tubing, current domestic gas well did not use pipe outer wall (or outside) with the oil pipe of heat-insulation layer, in gas well, do not used the oil pipe with insulation construction (or function) yet.

From open source information and knowledge known in this field: steel exist brittle temperature, natural gas production process, rules and regulations and relevant GB, Industry code requirements natural gas line, pipe fitting, equipment prolonged cold running temperature are not less than-20 DEG C, do not allow its longtime running at a temperature of-20 DEG C.

Calculated from knowledge known in this field and thermodynamics knowledge: in Wellbore of Gas Wells, natural gas temperature is higher than formation temperature, natural gas can pass through the annular space → sleeve pipe → cementing concrete ring approach of oil pipe → casing tube composition and dispel the heat to stratum, increases the thermal resistance of any one link in this sinking path and all can reduce its heat transfer coefficient.Therefore, when oil pipe used in Wellbore of Gas Wells changes insulated tubing into, natural gas can be greatly reduced by the heat dissipation capacity of this approach, and natural gas rises to the temperature of well head and can be greatly improved.

From open source information and knowledge known in this field: coiled tubing has the function of oil pipe, it is possible to replace oil pipe to produce natural gas in the natural gas well.Compared with oil pipe, coiled tubing has length length, the feature such as flexible, and its external diameter, internal diameter can be as oil pipes, it is also possible to more than or less than oil pipe internal-and external diameter.The coiled tubing less than pipe aperture is generally put in the existing oil pipe of gas well by revive at present Sulige gas field, gas field of pacifying the border region, and is used for getting rid of the hydrops in Wellbore of Gas Wells.

From knowledge known in this field: heat-insulation layer can be made at coiled tubing outer wall by existing method, as made, at the coiled tubing outer wall that external diameter is 40mm, the rubber heat-insulation layer that thickness is 5mm by existing method.With the method for existing method such as underground work can be 50mm by external diameter, in outer wall have the coiled tubing of 5mm rubber heat-insulation layer to put into oil pipe that the existing internal diameter of gas well is 76mm.

Open source information shows: there is inner via hole at hollow rod center, it is possible to pass through fluid.The domestic hollow rod that commonly uses in oil well, but domestic do not apply at present hollow rod replace oil pipe and allow natural gas rise to the precedent of well head by hollow rod in Wellbore of Gas Wells.

From knowledge known in this field: hollow rod can be metal material, it is also possible to be the non-metallic material such as fiberglass, carbon fiber.Hollow rod replaces oil pipe put in gas well sleeve pipe, it is possible to function similarly to the effect of oil pipe, it is possible to meet natural gas well production requirement and regulation, hollow rod can be put in gas well sleeve pipe by the method for existing method such as underground work.

From knowledge known in this field: the external diameter of hollow rod is generally less than 40mm, it is generally less than 50mm, still less than Soviet Union's Sulige gas field, the gas field gas wells such as gas field of pacifying the border region now with more than pipe aperture 26mm with existing method external diameter after outer wall parcel 5mm heavy sheet glass steel heat-insulation layer；The hollow rod that outer wall can wrap up 5mm heavy sheet glass steel heat-insulation layer by the method for existing method such as underground work is put in the oil pipe that the existing internal diameter of gas well is 76mm.

From knowledge known in this field: in Wellbore of Gas Wells, oil pipe connects as communicating pipe with sleeve pipe by shaft bottom, it is generally less than 5MPa with the pressure reduction in sleeve pipe in oil pipe and this pressure reduction is mainly flow differential pressure, allow to reveal a small amount of natural gas from oil pipe to sleeve pipe, allow also to reveal a small amount of natural gas from sleeve pipe to oil pipe.Therefore, described specialty metal pipe replacement oil pipe is put in gas well sleeve pipe, it is possible to function similarly to the effect of oil pipe, it is possible to meet natural gas well production requirement and regulation.

Open source information shows: nonmetallic thermal resistance is much larger than metal, if the thermal resistance of aluminium-plastic pipe is much larger than equivalent diameter, the metal tube of wall thickness, oil pipe, if the heat-resistant rubber hose of a layer thickness 5mm on aluminium-plastic pipe outer wall overlaps again, its thermal resistance is understood the biggest by thermodynamic computing, can effectively reduce natural gas heat loss in Wellbore of Gas Wells, improve natural gas and rise to the temperature of gas well mouth, natural gas even can be allowed to rise to the temperature of well head more than 60 DEG C.Domestic non-metallic pipe is not applied at present to replace oil pipe and allow natural gas rise to the precedent of well head by non-metallic pipe in Wellbore of Gas Wells.

From knowledge known in this field: commodity aluminium-plastic pipe belongs to non-metallic pipe, can pressure 10MPa, there is good hardness and flexibility, it is possible to be firmly connected with other non-metallic pipes, metal tube, metal tube by commodity connector, there is the biggest thermal resistance, domestic be commonly used to heating and delivery；Use it for gas well replaces oil pipe, it is possible to effectively reduce natural gas heat loss in Wellbore of Gas Wells, improve natural gas and rise to the temperature of gas well mouth, natural gas even can be allowed to rise to the temperature of well head more than 45 DEG C.Therefore, described special nonmetal pipe replacement oil pipe is put in gas well sleeve pipe, it is possible to function similarly to the effect of oil pipe, it is possible to meet natural gas well production requirement and regulation.

If existing Wellbore of Gas Wells sleeve pipe placed oil pipe；In order to insulated tubing being put in the Wellbore of Gas Wells sleeve pipe of oil pipe, replace the existing oil pipe in Wellbore of Gas Wells with insulated tubing, first existing oil pipe in Wellbore of Gas Wells sleeve pipe can be taken out, the most again insulated tubing be put in Wellbore of Gas Wells sleeve pipe.

Open source information shows: underground work is the mature technology that natural gas produces, and can be taken out by the oil pipe in Wellbore of Gas Wells sleeve pipe by the method, and be put into by insulated tubing in Wellbore of Gas Wells sleeve pipe.

If already provided with special downhole choke device (such as subsurface choke) in existing Wellbore of Gas Wells sleeve pipe placed oil pipe and this oil pipe；In order to insulated tubing being put in oil pipe and this oil pipe Wellbore of Gas Wells sleeve pipe already provided with special downhole choke device (such as subsurface choke), the existing oil pipe in gas well and special downhole choke device is replaced: first can be taken out by the special downhole choke device arranged in oil pipe existing in Wellbore of Gas Wells sleeve pipe and this oil pipe, be put in Wellbore of Gas Wells sleeve pipe by insulated tubing with insulated tubing.

Open source information shows: underground work is the mature technology that natural gas produces, the special downhole choke device (such as subsurface choke) arranged in existing oil pipe in Wellbore of Gas Wells sleeve pipe and this oil pipe can be taken out by the method, and insulated tubing be put in Wellbore of Gas Wells sleeve pipe.

In order to be put into by insulated tubing in the existing oil pipe of Wellbore of Gas Wells, need the insulated tubing using external diameter less than the existing pipe aperture of Wellbore of Gas Wells；External diameter is put in Wellbore of Gas Wells oil pipe less than the insulated tubing of the existing pipe aperture of Wellbore of Gas Wells.

From knowledge known in this field: typically there is oil pipe in gas well sleeve pipe, in the existing oil pipe in gas well sleeve pipe, placing into the oil pipe less than this existing pipe aperture is that natural gas production process, rules and regulations are allowed；Underground work is the mature technology that natural gas produces, and external diameter can be put in Wellbore of Gas Wells oil pipe less than the insulated tubing of the existing pipe aperture of gas well by the method.

In order to be put into by insulated tubing in the Wellbore of Gas Wells oil pipe already provided with special downhole choke device (such as subsurface choke), need the insulated tubing using external diameter less than the existing pipe aperture of Wellbore of Gas Wells；First the special downhole choke device (such as subsurface choke) in Wellbore of Gas Wells oil pipe is taken out, the most again external diameter is put in Wellbore of Gas Wells oil pipe less than the insulated tubing of the existing pipe aperture of Wellbore of Gas Wells.

Open source information shows: underground work is the mature technology that natural gas produces, the special downhole choke device (such as subsurface choke) arranged in Wellbore of Gas Wells oil pipe can be taken out by the method, and external diameter can be put in Wellbore of Gas Wells oil pipe less than the insulated tubing of the existing pipe aperture of Wellbore of Gas Wells.

Further, for solving above-mentioned technical problem, one natural gas production method of the present invention, comprise the steps:

1), insulated tubing is put in Wellbore of Gas Wells sleeve pipe or in oil pipe；

2), natural gas is allowed to rise to well head by insulated tubing；

3), natural gas is allowed to rely on own temperature reducing pressure by regulating flow in well site, to reduce natural gas energy consumption；

4), the natural gas after reducing pressure by regulating flow is delivered to gas gathering station；

Described insulated tubing should be able to allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate or/and natural gas temperature after well site relies on own temperature reducing pressure by regulating flow can be allowed to be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C, should be able to put in Wellbore of Gas Wells sleeve pipe or in oil pipe by existing method, gas well liquid loading requirement and regulation should be met；As those of ordinary skill in the art, the particular type of described insulated tubing is can determine by existing method, structure, physical dimension, material, service life, make technique, can determine the particular type of described insulated tubing outer wall (or outside) heat-insulation layer, structure, physical dimension, material, maximum gauge, minimum thickness, heat conductivity, make technique, can determine that described insulated tubing is incubated, adiabatic, the concrete form of heat insulation structural, type, physical dimension, material, heat conductivity, make technique, can determine that the particular number in Wellbore of Gas Wells sleeve pipe or in oil pipe put into by described insulated tubing, length (or degree of depth), position.

Described reducing pressure by regulating flow should be able to reduce natural gas energy consumption and cost, should be able to meet the production requirement of natural gas well site and regulation, should be able to meet the gas gathering station production requirement of natural gas and regulation to entering this station；As those of ordinary skill in the art, the concrete scheme of described reducing pressure by regulating flow, mode, Restriction Parameters, restricting element is can determine, it is possible to determine natural gas maximum temperature after described reducing pressure by regulating flow, minimum temperature, optimum temperature, maximum pressure, minimum pressure, optimum pressure by existing method.

Described reducing pressure by regulating flow may refer to well site surface throttling blood pressure lowering, it is also possible to refers to well head reducing pressure by regulating flow；The surface throttling blood pressure lowering of described well site refers to utilize and is arranged on the private section fluid element (such as oil nozzle) on ground, well site or underground or/and the pipe fitting (such as valve, reducer pipe, orifice plate etc.) that can effectively reduce gas pressure reduces gas pressure；Described well head reducing pressure by regulating flow refers to utilize and is arranged on the private section fluid element (such as oil nozzle) of well mouth oil pipe outlet or/and the pipe fitting (such as valve, reducer pipe, orifice plate etc.) that can effectively reduce gas pressure reduces gas pressure；Described reducing pressure by regulating flow can be one-level (the most disposable) reducing pressure by regulating flow, it is also possible to be 2 grades or multi-level throttle blood pressure lowering.

From knowledge known in this field: reducing pressure by regulating flow is mature technology, the method commonly used during natural gas produces.Natural gas, when well site reducing pressure by regulating flow, generally completes with oil nozzle, needle valve, special choke valve, and have also completes with other pipe fitting such as reducer pipes, orifice plate, valve etc. that can effectively reduce gas pressure；Commonly use and be arranged at the special pipe fitting on ground, well site or underground, valve group reducing pressure by regulating flow, through frequently with the method at the upper reducing pressure by regulating flow of well head (christmas tree)；The method being also adopted by and/or ground (or underground) valve group secondary upper at well head (christmas tree) or repeatedly reducing pressure by regulating flow (also known as two grades or multi-level throttle blood pressure lowering) that is commonly used at well head (christmas tree) or the method for the disposable reducing pressure by regulating flow of surface valve group (also known as one-level reducing pressure by regulating flow), that have.

From knowledge known in this field: Soviet Union's Sulige gas field, gas field of pacifying the border region, Yulin Gas Field, the natural gas purification processing factory commonly used propane deep cooling dewatering of DaNiuDi gas field reduce gas dew point, the method is to be cooled by natural gas to-8 DEG C of removings moisture content (will gas dew point be down to-8 DEG C), typically require that the natural gas temperature that gas gathering station enters purifying plant is-8～18 DEG C, in the range of-8～18 DEG C, the natural gas temperature that gas gathering station enters purifying plant is the lowest, and energy, cost that purifying plant is consumed are the lowest；In natural gas winter production, the natural gas temperature entering gas gathering station is that production technology, rules and regulations are allowed less than 0 DEG C, and is a kind of common phenomenon.

From knowledge known in this field: in the existing reducing pressure by regulating flow in well site produces, all use heating → reducing pressure by regulating flow method, the most first use heating furnace heated natural gas before natural gas reducing pressure by regulating flow.If natural gas is the most first heat temperature raising before reducing pressure by regulating flow, the natural gas temperature after reducing pressure by regulating flow and natural gas line, pipe fitting, equipment running temperature can be made to be down to less than-20 DEG C.

Further, step 3) in, in order to generate hydrate, ice in preventing natural gas pipeline pipe fitting when well site reducing pressure by regulating flow and after reducing pressure by regulating flow: first add antifreezing agent in natural gas, allow natural gas rely on own temperature at well site reducing pressure by regulating flow the most again.Its reason is, in natural gas produces, the gas deliverability of different gas wells may be different, and some gas well gas production are high, and some gas well gas production are low.Temperature when natural gas rises to well head from shaft bottom is relevant with gas production (or flow that natural gas is in pit shaft), and under equal conditions, gas production is the least, and the temperature that natural gas arrives well head is the lowest；Therefore, the gas well that gas production is relatively low, the temperature that natural gas rises to well head is relatively low, for avoiding the temperature when well site reducing pressure by regulating flow and after reducing pressure by regulating flow to be likely lower than hydrate critical generation temperature, can add antifreezing agent and prevent hydrate from generating before reducing pressure by regulating flow.

Described reducing pressure by regulating flow can be one-level or more than 2 grades reducing pressure by regulating flows.

From knowledge known in this field: in natural gas produces, the commonly used method adding methanol in pit shaft oil pipe or sleeve pipe, prevent gas hydrates from generating.

Further, step 3) in, the antifreezing agent consumption required when well site reducing pressure by regulating flow in order to reduce natural gas: first allow natural gas rely on own temperature to carry out reducing pressure by regulating flow first in well site；Then allow the natural gas after reducing pressure by regulating flow first enter in gas-liquid separator and isolate liquid, and by existing method, isolated liquid is carried out subsequent treatment；Antifreezing agent is added the most again in isolated natural gas；The natural gas carrying antifreezing agent is allowed to rely on own temperature to carry out second time reducing pressure by regulating flow in well site the most again.

Described reducing pressure by regulating flow first, it is ensured that the temperature after natural gas relies on own temperature reducing pressure by regulating flow generates critical temperature and freezing point higher than hydrate and will not generate hydrate or ice in gas-liquid separator, should be able to meet the production requirement of natural gas well site and regulation；As those of ordinary skill in the art, the concrete scheme of described reducing pressure by regulating flow, mode, Restriction Parameters, restricting element is can determine, it is possible to determine natural gas maximum temperature after described reducing pressure by regulating flow first, minimum temperature, optimum temperature, maximum pressure, minimum pressure, optimum pressure by existing method.

Described second time reducing pressure by regulating flow should be able to meet the production requirement of natural gas well site and regulation, should be able to meet the gas gathering station production requirement of natural gas and regulation to entering this station；As those of ordinary skill in the art, the concrete scheme of described reducing pressure by regulating flow, mode, Restriction Parameters, restricting element is can determine, it is possible to determine natural gas maximum temperature after described second time reducing pressure by regulating flow, minimum temperature, optimum temperature, maximum pressure, minimum pressure, optimum pressure by existing method.

Described reducing pressure by regulating flow first, for the second time reducing pressure by regulating flow can be one-level or more than 2 grades reducing pressure by regulating flows.

Described gas-liquid separator can be 1 or more than 2, and more than 2 can be in parallel or series.

Described antifreezing agent should meet natural gas production requirement and regulation, cannot form hydrate, ice in should ensure that natural gas pipeline pipe fitting when reducing pressure by regulating flow first, reducing pressure by regulating flow for the second time and after reducing pressure by regulating flow；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

From knowledge known in this field: the manufacturing cost of gas-liquid separator is relevant with its pressure rating with difficulty, the highest manufacture difficulty of pressure, cost are the highest, because of natural gas via, to cross the pressure after reducing pressure by regulating flow the most decreased, and the gas-liquid separator manufacturing cost and the difficulty that carry out gas-liquid separation the most again also can reduce.

Further, step 3) in, in order to utilize big geothermal energy to reduce the antifreezing agent consumption that natural gas dependence own temperature is required when well site reducing pressure by regulating flow: first add antifreezing agent in natural gas, then natural gas is allowed to rely on own temperature and underground heat repeatedly reducing pressure by regulating flow in buried gathering line between well site to gas gathering station, in order to allow natural gas pass through buried gathering line and heat up from the earth heat absorption.

Described repeatedly reducing pressure by regulating flow may refer between well site to gas gathering station more than 2 grades reducing pressure by regulating flows of optional position on buried gathering line, may refer to the reducing pressure by regulating flow utilizing proprietary restricting element (such as oil nozzle) to carry out, it is also possible to refer to utilize reducer pipe, orifice plate, valve etc. can effectively reduce the reducing pressure by regulating flow that the pipe fitting of gas pressure is carried out.

Described antifreezing agent should meet natural gas production requirement and regulation, cannot form hydrate, ice in should ensure that natural gas pipeline pipe fitting when at well site reducing pressure by regulating flow and after reducing pressure by regulating flow；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

Described repeatedly reducing pressure by regulating flow should meet natural gas production requirement and regulation, antifreezing agent consumption should be able to be greatly reduced, big geothermal energy should be able to be utilized to allow the temperature of natural gas in-line be higher than 0 DEG C and less than the buried mean annual cost of gathering line between well site to gas gathering station or less than 10 DEG C.As those of ordinary skill in the art, with existing method can determine described in the repeatedly concrete scheme of reducing pressure by regulating flow, throttle style, restricting element, Restriction Parameters, maximum reducing pressure by regulating flow pressure and temperature, minimum reducing pressure by regulating flow pressure and temperature, optimal reducing pressure by regulating flow pressure and temperature.

Open source information and knowledge known in this field show: gas field of pacifying the border region, Soviet Union's Sulige gas field, DaNiuDi gas field well site to gas gathering station between be not incubated gathering line and be all embedded in and freeze below layer (less than 1.6 meters), buried average temperature of the whole year 9 DEG C, length is generally 500～ten thousand metres.

Open source information shows: ground temperature can freeze less than 0 DEG C, and after frost in the soil, heat conductivity drastically declines.

From knowledge known in this field: the buried gathering line buried depth between well site to gas gathering station is all freezing below layer, mean annual cost, at about 9 DEG C, can absorb heat from the earth when the natural gas temperature in pipeline is less than the buried temperature of pipeline and heat up；The thermal capacitance of the earth is unlimited；Natural gas is big ground soil thermal conductivity from the restricted pipeline of heat that the earth absorbs, and outside pipeline, during big ground frost in the soil, heat conductivity can drastically decline；Existing reducing pressure by regulating flow method can arbitrarily reduce natural pressure force value, can the natural gas temperature that carry antifreezing agent be controlled in 0～9 DEG C by the method for reducing pressure by regulating flow.

Further, step 3) in, in order to utilize big geothermal energy to reduce the antifreezing agent consumption that natural gas dependence own temperature is required when well site reducing pressure by regulating flow: first can also add antifreezing agent in natural gas；The natural gas carrying antifreezing agent is allowed to rely on own temperature at well site reducing pressure by regulating flow the most again；The natural gas after the reducing pressure by regulating flow of well site is allowed to rely on own temperature and underground heat repeatedly reducing pressure by regulating flow in buried gathering line between well site to gas gathering station the most again, in order to allow natural gas pass through buried gathering line and heat up from the earth heat absorption.

Described well site reducing pressure by regulating flow should meet natural gas production requirement and regulation, natural gas temperature after reducing pressure by regulating flow should be able to be allowed to generate critical temperature and higher than 0 DEG C higher than hydrate, and less than the buried mean annual cost of gathering line between local well site to gas gathering station or less than 10 DEG C.As those of ordinary skill in the art, can determine the concrete scheme of described well site reducing pressure by regulating flow, throttle style, restricting element, Restriction Parameters, maximum reducing pressure by regulating flow pressure and temperature, minimum reducing pressure by regulating flow pressure and temperature, optimal reducing pressure by regulating flow pressure and temperature by existing method.

Described repeatedly reducing pressure by regulating flow should meet natural gas production requirement and regulation, antifreezing agent consumption should be able to be greatly reduced, big geothermal energy should be able to be utilized to allow the temperature of natural gas in-line be higher than 0 DEG C and less than the buried mean annual cost of gathering line between well site to gas gathering station or less than 10 DEG C.As those of ordinary skill in the art, can determine in described pipeline the repeatedly concrete scheme of reducing pressure by regulating flow, throttle style, restricting element, Restriction Parameters, maximum reducing pressure by regulating flow pressure and temperature, minimum reducing pressure by regulating flow pressure and temperature, optimal reducing pressure by regulating flow pressure and temperature by existing method.

Described well site reducing pressure by regulating flow can be 1 grade or more than 2 grades reducing pressure by regulating flows.

Described antifreezing agent should meet natural gas production requirement and regulation, should ensure that natural gas cannot form hydrate, ice when well site reducing pressure by regulating flow and between well site to gas gathering station in buried gathering line；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

It is further possible to first allow natural gas rely on own temperature at well site reducing pressure by regulating flow；Then allow the natural gas after reducing pressure by regulating flow enter in the gas-liquid separator that well site is arranged and isolate liquid, and by existing method, liquid is carried out subsequent treatment；Antifreezing agent is added the most again in isolated natural gas；The natural gas carrying antifreezing agent is allowed to rely on own temperature and underground heat repeatedly reducing pressure by regulating flow in buried gathering line between well site to gas gathering station the most again, in order to allow natural gas pass through buried gathering line and heat up from the earth heat absorption and save antifreezing agent consumption.

Further, step 4) in, in order to the natural gas after preventing reducing pressure by regulating flow generates hydrate, ice between well site to gas gathering station in gathering line: first the natural gas after reducing pressure by regulating flow adds antifreezing agent, the most again the natural gas after reducing pressure by regulating flow is delivered to gas gathering station.

Described antifreezing agent should meet natural gas production requirement and regulation, should ensure that natural gas cannot form hydrate, ice between well site to gas gathering station in pipeline；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

From knowledge known in this field: between domestic gas well well site to gas gathering station gathering line have buried have ground lay, the buried gathering line of major part is not incubated (gas field of such as pacifying the border region, the gas wells such as 11 blocks of reviving), and its buried temperature is often below gas hydrates and generates critical temperature；Pacify the border region gas field, Soviet Union's Sulige gas field etc. is positioned in desert, and its buried pipeline is often exposed to earth's surface because of sand dune movement, and the natural gas temperature in pipeline sometimes can be allowed less than 0 DEG C；Natural gas temperature after the reducing pressure by regulating flow of well site generates critical temperature less than hydrate but is that natural gas produces and rules and regulations are allowed higher than-20 DEG C.

From knowledge known in this field: in natural gas produces, generally take the method adding antifreezing agent in natural gas to prevent between well site to gas gathering station and in pipeline, generate hydrate.

Further, step 4) in, in order to the natural gas after preventing reducing pressure by regulating flow generates hydrate between well site to gas gathering station in gathering line: with hot insulated line, the natural gas after reducing pressure by regulating flow can also be delivered to gas gathering station.

Further, it is also possible to first by existing method, the gathering line that is not incubated between well site to gas gathering station is incubated, then with insulation rear line, the natural gas after reducing pressure by regulating flow is delivered to gas gathering station.

Natural gas after described insulation should ensure that reducing pressure by regulating flow cannot generate hydrate, ice in described insulation rear line, should meet gas well liquid loading requirement and regulation；As those of ordinary skill in the art, can determine the concrete scheme of described insulation, method by existing method, it is possible to determine the heat conductivity of described insulation rear line heat-insulation layer, maximum gauge, minimum thickness, Acceptable life.

From knowledge known in this field: buried pipeline yellow jacket polyurethane insulation coating insulation between gas well (such as Su10 Block) well site to the gas gathering station having；When between well site to gas gathering station, buried pipeline is with yellow jacket polyurethane insulation coating insulation, it is possible to effectively reduce temperature drop and the heat loss of natural gas in pipeline.

From knowledge known in this field: Soviet Union's Sulige gas field, buried pipeline between existing well site to the gas gathering station in addition to Su10 Block of the gas field of pacifying the border region are not incubated, it is typically designed buried depth 1.6 meters (freezing 1.5 meters of layer), average annual 9 DEG C of corresponding buried temperature, minimum buried ground temperature 5 DEG C；Natural gas will not generate hydrate when entering between existing well site to gas gathering station the temperature before buried not hot insulated line higher than hydrate critical generation temperature, but be not incubated buried pipeline by this and can generate hydrate to the earth radiating and cooling to during less than hydrate critical generation temperature.

From knowledge known in this field: be maturation method conventional during oil gas field produces to be not incubated buried or surface gathering and transferring pipeline between well site to gas gathering station carrying out yellow jacket polyurethane foam plastics heat-insulation layer insulation.

Further, step 4) in, in order to the natural gas after reducing antifreezing agent consumption and preventing reducing pressure by regulating flow generates hydrate between well site to gas gathering station in gathering line: can also first allow the natural gas after reducing pressure by regulating flow enter in the gas-liquid separator that well site is arranged, by gas-liquid separator, natural gas is separated with liquid, and by existing method, isolated liquid is carried out subsequent treatment；In isolated natural gas, add antifreezing agent the most again, then the natural gas carrying antifreezing agent is delivered to gas gathering station.

Further, it is also possible to first allow the natural gas after reducing pressure by regulating flow enter in the gas-liquid separator that well site is arranged, by gas-liquid separator, natural gas is separated with liquid, and by existing method, isolated liquid is carried out subsequent treatment；Then isolated natural gas hot insulated line or the existing gathering line that has been incubated are delivered to gas gathering station.

Described gas-liquid separator can be 1 or more than 2, and more than 2 gas-liquid separators carry out parallel connection or/and connect.

Described liquid can be the mixing liquid of aqueous water or liquid hydrocarbon and water composition.

The liquid of more than 50% in natural gas should be able to be separated from natural gas by described gas-liquid separator, should be able to meet natural gas production requirement and regulation；As those of ordinary skill in the art, can determine the particular type specification of described gas-liquid separator, method for making, installation method, using method by existing method, at most quantity is set, minimum quantity is set, it is possible to determine more than 2 gas-liquid separation implement body installation methods in parallel or series, usings method.

Described hot insulated line, the existing gathering line being incubated should ensure that natural gas cannot generate hydrate, ice in this pipeline, should meet gas well liquid loading requirement and regulation；As those of ordinary skill in the art, by existing method can determine the concrete thermal retardation form of described hot insulated line, type, structure, physical dimension, material, Acceptable life, make technique, it is possible to the heat conductivity of existing gathering line heat-insulation layer that determine described hot insulated line, carries out being incubated, maximum gauge, minimum thickness, Acceptable life.

From knowledge known in this field: in the reducing pressure by regulating flow mode of production of the most existing natural gas well site, all use heating → reducing pressure by regulating flow method, the method not using reducing pressure by regulating flow → gas-liquid separation in well site in well site, be required to heating furnace heating.

From knowledge known in this field: be the mature technology commonly used during natural gas produces with the aqueous water (free water) in gas-liquid separator separating natural gas, liquid hydrocarbon.

Further, in order to prevent the liquid separated from natural gas in gas-liquid separator and liquid outlet freezes, generates hydrate: described gas-liquid separator and liquid outlet are incubated with existing heat preserving method, or with existing solar energy heating method tracing thermal-insulating.

Described insulation, solar energy tracing thermal-insulating should meet natural gas production requirement and regulation, should be able to allow isolated liquid will not in gas-liquid separator and liquid outlet freeze；As those of ordinary skill in the art, can determine insulation, the specific category of solar energy tracing thermal-insulating, mode, effective using method, concrete insulation material, concrete insulation layer thickness, concrete thermal-insulating scheme by existing method.

Further, in order to prevent the liquid separated from natural gas in gas-liquid separator and liquid outlet freezes, generates hydrate: can be by the buried or buried insulation of existing method of described gas-liquid separator.

Open source information shows: freeze average annual 9 DEG C of the following ground temperature of layer.

2), natural gas is allowed to rise to well head by insulated tubing.

3), with hot insulated line, natural gas is delivered to gas gathering station.

4), natural gas is allowed to rely on own temperature reducing pressure by regulating flow in gas gathering station, to reduce natural gas energy consumption.

Described reducing pressure by regulating flow may refer to the reducing pressure by regulating flow of optional position, operation in gas gathering station, it is also possible to refers to the reducing pressure by regulating flow (in heating furnace) in equipment, it is also possible to refers to the reducing pressure by regulating flow on any pipeline, pipe fitting in gas gathering station；Described reducing pressure by regulating flow may refer to the reducing pressure by regulating flow utilizing private section fluid element (such as oil nozzle) to carry out, it is also possible to refers to utilize and can effectively reduce the reducing pressure by regulating flow that the pipe fitting (such as valve, reducer pipe, orifice plate etc.) of gas pressure is carried out；Described reducing pressure by regulating flow can be one-level reducing pressure by regulating flow, it is also possible to be 2 grades or multi-level throttle blood pressure lowering.

Described insulated tubing should be able to allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate or/and temperature after natural gas can be allowed to rely on own temperature, pressure and hot insulated line to be delivered to gas gathering station reducing pressure by regulating flow is not less than minimum operating temperature that natural gas line pipe fitting allowed or is not less than-20 DEG C, should be able to put in Wellbore of Gas Wells sleeve pipe or in oil pipe by existing method, gas well liquid loading requirement and regulation should be met；As those of ordinary skill in the art, the particular type of described insulated tubing is can determine by existing method, structure, physical dimension, material, service life, make technique, can determine the particular type of described insulated tubing outer wall (or outside) heat-insulation layer, structure, physical dimension, material, maximum gauge, minimum thickness, heat conductivity, make technique, can determine that described insulated tubing is incubated, adiabatic, the concrete form of heat insulation structural, type, physical dimension, material, heat conductivity, make technique, can determine that the particular number in Wellbore of Gas Wells sleeve pipe or in oil pipe put into by described insulated tubing, length (or degree of depth), position.

Described hot insulated line should be able to be greatly reduced natural gas heat loss between well site to gas gathering station in gathering line, should ensure that natural gas rely on own temperature, pressure to be delivered to gas gathering station reducing pressure by regulating flow after temperature be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C；As those of ordinary skill in the art, can determine the concrete thermal retardation form of described hot insulated line, type, structure, physical dimension, material, using method, service life by existing method, make technique, it is possible to determine the heat conductivity of described hot insulated line heat-insulation layer, maximum gauge, minimum thickness, using method, service life.

Described reducing pressure by regulating flow should be able to reduce natural gas energy consumption and cost, production requirement and the regulation of gas gathering station should be able to be met, natural gas processing purification plant should be able to be met to the production requirement of the natural gas from gas gathering station and regulation, natural gas processing purification plant should be conducive to reduce energy consumption and cost；As those of ordinary skill in the art, the concrete scheme of described reducing pressure by regulating flow, mode, Restriction Parameters, restricting element is can determine, it is possible to determine natural gas maximum temperature after described gas gathering station reducing pressure by regulating flow, minimum temperature, optimum temperature, maximum pressure, minimum pressure, optimum pressure by existing method.

From knowledge known in this field: Domestic Oil And Gas Fields buried pipeline, surface line commonly use yellow jacket polyurethane foam insulation layer insulation, the yellow jacket polyurethane foam insulation layer insulation of the pipeline between Sulige gas field Su10 Block well site to gas gathering station of Soviet Union is the most buried to freezing below layer (buried depth 1.6 meters).Accordingly, as those of ordinary skill in the art, it is possible to determine the concrete structure of hot insulated line heat-insulation layer, type, size, material, make technique, heat conductivity, it is possible to determine the maximum gauge of heat-insulation layer, minimum thickness, using method, service life.

From knowledge known in this field: when natural gas collecting station reducing pressure by regulating flow, generally reducing pressure by regulating flow in heating furnace or/and on furnace outlet pipeline, reducing pressure by regulating flow on the pipeline before entering separator also having；Generally with the private section fluid element reducing pressure by regulating flow such as oil nozzle, needle valve, special choke valve, have also can effectively reduce the reducing pressure by regulating flow such as pipe fitting such as reducer pipe, orifice plate, gate valve of gas pressure with other；Commonly used once (one-level) throttling in heating furnace, the method that secondary (two grades) throttles on furnace outlet pipeline, have is also adopted by the method that once (one-level) throttles on furnace outlet pipeline；Commonly used one-level throttling, the first order heating furnace of carrying out before first order heating furnace in some gas fields (such as general smooth gas field) carries out two-step throttle, second level heating furnace carry out three grades of throttlings methods after reheating after heating.

From knowledge known in this field: in the reducing pressure by regulating flow of existing gas gathering station produces, all use heating → reducing pressure by regulating flow method, heating furnace heated natural gas is the most first used before natural gas reducing pressure by regulating flow, if natural gas is the most first heat temperature raising before reducing pressure by regulating flow, natural gas temperature and natural gas line, pipe fitting, equipment running temperature can be made to be down to less than-20 DEG C.

Further, step 3) in, temperature in order to prevent well head natural gas to be out delivered to during gas gathering station by existing not hot insulated line is the lowest: first by existing method to buried between well site to gas gathering station or surface gathering and transferring pipeline insulation, with insulation rear line, natural gas is delivered to gas gathering station the most again.

Described insulation, insulation rear line should be able to be greatly reduced natural gas heat loss between well site to gas gathering station in gathering line, should ensure that natural gas rely on own temperature, pressure to be delivered to gas gathering station reducing pressure by regulating flow after temperature be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C；As those of ordinary skill in the art, the concrete scheme of described insulation, method is can determine by existing method, can determine the concrete thermal retardation form of described insulation rear line, type, structure, physical dimension, material, using method, service life, make technique, it is possible to determine the heat conductivity of described insulation rear line heat-insulation layer, maximum gauge, minimum thickness, using method, service life.

Calculated from knowledge known in this field: gas field of pacifying the border region, Soviet Union Sulige gas field, DaNiuDi gas field are in addition to Su10 Block, and between well site to gas gathering station, buried collector and delivery pipe is not incubated；It is maturation method conventional during oil gas field produces to be not incubated buried or surface gathering and transferring pipeline between well site to gas gathering station carrying out yellow jacket polyurethane foam plastics heat-insulation layer insulation.

Further, step 4) in, in order to prevent natural gas from generating hydrate, ice when gas gathering station reducing pressure by regulating flow and after reducing pressure by regulating flow in gas gathering station pipeline pipe fitting: first add antifreezing agent in reducing pressure by regulating flow forward direction natural gas, allow natural gas rely on own temperature reducing pressure by regulating flow in gas gathering station the most again.

Described antifreezing agent should meet natural gas production requirement and regulation, should ensure that natural gas cannot form hydrate, ice when gas gathering station reducing pressure by regulating flow and after reducing pressure by regulating flow in gas gathering station pipeline pipe fitting；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

From knowledge known in this field and calculation of thermodynamics: in natural gas produces, the gas deliverability of different gas wells may be different, and some gas well gas production are high, and some gas well gas production are low.Temperature when natural gas rises to well head from shaft bottom is relevant with gas production (or flow that natural gas is in pit shaft), and under equal conditions, gas production is the least, and the temperature that natural gas arrives well head is the lowest；Therefore, the gas well that gas production is relatively low, the temperature that natural gas rises to well head by insulated tubing of the present invention is relatively low, temperature when gas gathering station reducing pressure by regulating flow and after reducing pressure by regulating flow is likely lower than hydrate critical generation temperature, needs to add antifreezing agent before reducing pressure by regulating flow for this and prevents hydrate from generating.

From knowledge known in this field: in natural gas produces, the method often taking to add antifreezing agent in pit shaft or well head or well site surface line (or pipe fitting) or buried gathering line pipe fitting, prevent natural gas from generating hydrate, ice before entering gas gathering station, also melt the hydrate of the gas gathering station favorite outer generation of gut line pipe fitting, ice through the conventional method adding antifreezing agent.

2), natural gas is allowed to rise to well head by insulated tubing；

3), in natural gas, antifreezing agent is added；

4) natural gas, is allowed to rely on own temperature to be delivered to gas gathering station by gathering line buried between well site to gas gathering station after well site reducing pressure by regulating flow is cooled to 0.5～9 DEG C, to allow natural gas pass through buried gathering line absorb heat from the earth, prevent natural gas from generating hydrate in gathering line；

5), allow natural gas enter in the gas-liquid separator that gas gathering station is arranged, by gas-liquid separator, natural gas is separated with liquid, and by existing method, isolated liquid is carried out subsequent treatment；

6), allow isolated natural gas rely on own temperature after gas gathering station reducing pressure by regulating flow is cooled to 0.5～9 DEG C by pipelined between the buried station of gas gathering station to purification plant to natural gas purification processing factory, to allow natural gas pass through pipeline between buried station absorb heat from the earth, prevent natural gas from pipeline, generating hydrate between station.

Further, allow the natural gas reducing pressure by regulating flow entering natural gas purification processing factory be cooled to more than-8 DEG C, enter back into the defeated operation of subsequent set or link.

Described reducing pressure by regulating flow can be 1 grade or more than 2 grades reducing pressure by regulating flows.

Described reducing pressure by regulating flow may refer to the reducing pressure by regulating flow utilizing proprietary restricting element (such as flow limit method) to carry out, it is also possible to refers to utilize reducer pipe, orifice plate, valve etc. can effectively reduce the reducing pressure by regulating flow that the pipe fitting of gas pressure is carried out.

Described insulated tubing should be able to allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate or/and natural gas can be allowed to rely on own temperature temperature after well site reducing pressure by regulating flow more than 10% to be not less than 0.5 DEG C；As those of ordinary skill in the art, the particular type of described insulated tubing is can determine by existing method, structure, physical dimension, material, service life, make technique, can determine the particular type of described insulated tubing outer wall (or outside) heat-insulation layer, structure, physical dimension, material, maximum gauge, minimum thickness, heat conductivity, make technique, can determine that described insulated tubing is incubated, adiabatic, the concrete form of heat insulation structural, type, physical dimension, material, heat conductivity, make technique, can determine that the particular number in Wellbore of Gas Wells sleeve pipe or in oil pipe put into by described insulated tubing, length (or degree of depth), position.

Described antifreezing agent should meet natural gas production requirement and regulation, should ensure that natural gas relies on own temperature, underground heat and antifreezing agent cannot form hydrate, ice；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

Further, step 6) in, in order to prevent natural gas from generating hydrate between gas gathering station to purification plant stand in pipeline: first add antifreezing agent in isolated natural gas；Allow the most again isolated natural gas rely on own temperature after gas gathering station reducing pressure by regulating flow is cooled to 0.5～9 DEG C by pipelined between the buried station of gas gathering station to purification plant to natural gas purification processing factory, to allow natural gas pass through pipeline between buried station absorb heat from the earth, prevent natural gas from pipeline, generating hydrate between station.

Open source information and knowledge known in this field show: during natural gas reducing pressure by regulating flow, temperature necessarily reduces.

Open source information and knowledge known in this field show: gas field of pacifying the border region, Soviet Union Sulige gas field, DaNiuDi gas field gas gathering station to purification plant station between pipeline be not incubated, all it is embedded in and freezes below layer (less than 1.6 meters), buried average temperature of the whole year 9 DEG C, length is generally 5000～300000 meters.

From knowledge known in this field: the gas gathering station natural gas temperature entering purification plant is that natural gas production process, rules and regulations are allowed less than 0 DEG C；Soviet Union's Sulige gas field, gas field of pacifying the border region, Yulin Gas Field, the natural gas purification processing factory commonly used propane deep cooling dewatering of DaNiuDi gas field reduce gas dew point, typically require that the natural gas temperature that gas gathering station enters purifying plant is-8～18 DEG C, the natural gas temperature of gas gathering station entrance purifying plant is the lowest within the range, and the energy, cost that purifying plant is consumed are the lowest；When the natural gas temperature that gas gathering station enters purifying plant reaches-8 DEG C, or when gas gathering station enter purification plant gas pressure higher ,-8 DEG C can be cooled to by reducing pressure by regulating flow in purification plant time, can also ensure that gas dew point is down to-8 DEG C without propane deep cooling dewatering.

Beneficial effects of the present invention is as follows: the present invention can make full use of natural energy in natural gas produces and produce natural gas, the wellhead temperature of the natural gas well can be greatly improved, can effectively solve the problem that hydrate affects the problem that natural gas produces, be capable of natural gas do not heat, not supercharging production technology, heating furnace heating, the defeated link of compressor boost collection can be cancelled, can significantly simplify natural gas production process, it is possible to be greatly reduced natural gas produce fixed investment, production cost, energy consumption, from air consumption, management workload etc.；There is enforcement easily, safe and reliable, it is widely used, promotes the excellent features such as easy.

Detailed description of the invention

Embodiment 1

One natural gas production method of the present invention, comprises the steps:

1), insulated tubing is put in Wellbore of Gas Wells sleeve pipe；

2), natural gas is allowed to rise to well head by insulated tubing；

Described insulated tubing is the oil pipe that vial outer wall (or outside) has heat-insulation layer；

Described insulated tubing is made by existing method；

Described insulated tubing inwall does not has undercoating；

Described insulated tubing can allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate or/and natural gas can be allowed to rely on own temperature temperature after well head or well site reducing pressure by regulating flow to be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C, can put in Wellbore of Gas Wells sleeve pipe or in oil pipe by existing method, meet gas well liquid loading requirement and regulation.

As a example by the newly-built gas well application present invention of gas field of pacifying the border region.

From knowledge known in this field: before the newly-built gas well in gas field of pacifying the border region builds up, only have sleeve pipe in pit shaft, there is no oil pipe；After oil pipe being put in sleeve pipe by existing method, gas well just can build up production；

Open source information shows: gas field of pacifying the border region is positioned at Ordos, inner Mongolia desert area, and winter minimum temperature reaches-31 DEG C；

The operational data in gas field of pacifying the border region shows: gas field average well depth about 3500 meters of pacifying the border region, shaft bottom gas-bearing formation temperature about 110 DEG C, pressure about 22MPa, general daily output tolerance 1～50,000 mark side/day, part gas well daily output tolerance is more than 50,000 mark sides/day, and part gas well daily output tolerance is less than 10,000 mark sides/day；This gas field gas well all uses plain tubing, sleeve structure, oil pipe used is generally external diameter 89mm, internal diameter 76mm metal blank tubing, without reducing pressure by regulating flow device in down-hole oil tube, well head, well site surface line pipe fitting are not incubated, well head is 500～ten thousand metres to the defeated distance of collection (also known as collecting defeated radius) of gas gathering station, gathering line between well site to gas gathering station is buried not hot insulated line, design the buried degree of depth 1.6 meters (freezing 1.5 meters of layer), 1.6 meter layer year-round average temperature are 9 DEG C, and winter minimum temperature is less than 5 DEG C；During this gas field gas well winter production, wellhead temperature temperature is generally 8～15 DEG C, and well head oil pressure (oil pipe export gas pressure) generally 15～20MPa, casing pressure (wellhead casing pipe pressure) is 16～22MPa.When the new well of this gas field operation in winter produces, wellhead temperature is generally 10～17 DEG C, and well head oil pressure (oil pipe export gas pressure) generally 19～20MPa, casing pressure (wellhead casing pipe pressure) is 20～22MPa.

This gas field employing well head adds methanol-gas gathering station and adds thermal throttle production technology, this technique can be summarized as: adds 50～1200L/ days of methanol in gas well oil pipe or/and in the pipeline of well site with high-pressure pump, the natural gas carrying methanol is allowed to be delivered to gas gathering station by the buried gathering line that is not incubated between well site to gas gathering station, then after utilizing gas gathering station internally heated oven heat temperature raising, throttling is depressurized to about 4MPa, and outer natural gas purification processing station-service propane refrigeration method of transporting to reduces dew point.

On-the-spot test shows: this gas field producing well actual measurement well mouth oil pipe outlet pressure in winter is 16～21MPa, actual measurement well head natural gas temperature in winter is 4～13 DEG C, it is 15～20MPa that actual measurement gathering line enters the Inlet pressure of gas gathering station, it is-4～9 DEG C that actual measurement gathering line in winter enters the natural gas temperature of gas gathering station, and actual measurement individual well in winter adds 200～800L/ days of methanol.

Calculated from knowledge known in this field: pressure is that to generate critical temperature be 22.1 DEG C for the gas field gas hydrates of pacifying the border region of 20MPa, pressure be the gas field gas hydrates generation critical temperature of pacifying the border region of 22MPa be 23 DEG C；Therefore, during the newly-built gas well in this gas field winter production, temperature when natural gas rises to well head generates critical temperature already below hydrate, inevitable on pit shaft oil pipe top, well head form Hydrate Plugging, if do not solved, newly-built gas well will be caused to produce.To this end, during the newly-built gas well liquid loading in this gas field, need to add methanol in gas well to prevent water compound from generating.

In order to avoid using the many disadvantages of methanol during newly-built gas well liquid loading, prevent pit shaft oil pipe top, well head from generating hydrate, this gas field newly-built gas well application present invention, its technical scheme is: in newly-built gas well process of construction of pacifying the border region, first by existing method, insulated tubing is put in sleeve pipe, allow natural gas rise to well head by insulated tubing by existing method the most again；Described insulated tubing external diameter 99mm, makes with external diameter 89mm, internal diameter 76mm oil pipe and existing method, and inwall does not has undercoating, outer wall to have the glass fibre reinforced plastic insulation layer of thickness 5mm, heat conductivity 0.4W/m.K.

Open source information shows: can make outer wall by oil pipe and existing method has thickness 5mm, the insulated tubing of heat conductivity 0.4W/m.K glass fibre reinforced plastic insulation layer.

Calculated from knowledge known in this field: the casing inner diameter that the newly-built gas well in gas field of pacifying the border region uses is generally higher than 150mm, described insulated tubing external diameter 99mm, therefore, it is possible to form the annular space of more than width 25mm with sleeve pipe, meet gas well liquid loading requirement and regulation；By operational method under existing well, the insulated tubing of external diameter 99mm can be put into the internal diameter gas well sleeve pipe more than 150mm.

Calculated from knowledge known in this field: if the newly-built gas well in gas field of pacifying the border region uses technical scheme of the present invention to carry out winter production, averagely produce tolerance 10,000 mark side/day daily according to newly-built gas well to count, the temperature that natural gas rises to well head from shaft bottom by insulated tubing of the present invention can reach more than 65 DEG C, exceed the wellhead temperature 48 of existing newly-built gas well plain tubing winter production～55 DEG C, be significantly larger than 22MPa natural gas hydrate generate critical temperature 23 DEG C, it is impossible on oil pipe top, well head generate hydrate；Calculating further and understand, the average daily output tolerance of newly-built gas well is the highest, and its wellhead temperature is the highest, and average daily output tolerance will be more than 65 DEG C more than the newly-built gas well mouth temperature of 10,000 mark sides/day.

Therefore, after the newly-built gas well application present invention of gas field of pacifying the border region, also ensure that newly-built gas well normally produces winter without methanol, thus avoid the many disadvantages using methanol.

Embodiment 2

Repeat embodiment 1, it the difference is that only: step 1) in, have in the gas well sleeve pipe of oil pipe at present in order to insulated tubing is put into, the existing oil pipe in Wellbore of Gas Wells is replaced: first taken out by existing oil pipe in Wellbore of Gas Wells sleeve pipe, put in Wellbore of Gas Wells sleeve pipe by insulated tubing with insulated tubing.

Open source information shows: underground work is the mature technology that natural gas produces, and can be taken out by the oil pipe in gas well sleeve pipe by the method, and be put in gas well sleeve pipe by insulated tubing of the present invention.

As a example by the Soviet Union 10-50-54 well application present invention.

The operational data of Soviet Union's Sulige gas field shows: Soviet Union's 10-50-54 well belongs to Soviet Union's No. 2 existing producing wells of gas gathering station of Sulige gas field Su10 Block, well depth about 3500 meters, shaft bottom natural gas temperature about 110 DEG C, bottom pressure about 20MPa, employing oil pipe produces, oil pipe used is external diameter 89mm, internal diameter 76mm plain tubing, without special downhole choke device in oil pipe, uses Special oil nozzle reducing pressure by regulating flow again, adjusts gas production after using the heating furnace heated natural gas being arranged at well site；When this well produces, the blocking of pit shaft oil pipe top frequently, every time after blocking i.e. with manually from well head to the method de-plugging adding methanol in oil pipe, it is sometimes desirable to repeatedly could release pit shaft for 2～4 times and block；To this end, the method manually adding 50 liters of methanol in oil well oil conduit every day taked by this well, and prevent oil pipe top from generating hydrate with the hot water of wellsite heater to the method for well head tracing thermal-insulating, it is ensured that gas well normally produces.On October 10th, 2008, survey this well casing pressure (suitable with pressure before reducing pressure by regulating flow at the bottom of the natural gas well) 20MPa, oil pressure (well mouth oil pipe export gas pressure) 19MPa, instantaneous gas production 1000m³/ h (is equivalent to produce tolerance 24000m daily³/ day), wellhead temperature 12 DEG C, aquifer yield 0.4～0.6 side/day.

Calculated from knowledge known in this field: Soviet Union's Sulige gas field gas hydrates critical generation temperature about 21.6 DEG C of pressure 19MPa, therefore the temperature 12 DEG C when this well natural gas rises to well head, already below hydrate critical generation temperature, necessarily forms this well well head of Hydrate Plugging, oil pipe top.Therefore, if this well prevents hydrate from generating without methanol, will be unable to normally produce.

Methanol and the variety of problems brought with wellsite heater hot water is manually added to well head tracing thermal-insulating in order to solve Soviet Union's 10-50-54 well, reduce gas well management workload degree, guarantee that gas well normally produces, this well applies the present invention to carry out pilot production in Decembers, 2008～in February, 2009, its technical scheme is: first taken out by existing external diameter 89mm oil pipe in Soviet Union's 10-50-54 well shaft sleeve pipe by the method for underground work, by the method for underground work, insulated tubing is put in this well shaft sleeve pipe the most again, then this well shaft bottom natural gas is allowed to rise to well head by insulated tubing by existing method；Described insulated tubing external diameter 99mm, makes with internal diameter 76mm, external diameter 89mm oil pipe and existing method, and inwall does not has undercoating, outer wall to have the glass fibre reinforced plastic insulation layer of thickness 5mm, heat conductivity 0.4W/m.K.

Calculated from knowledge known in this field and Soviet Union's Sulige gas field operational data: the casing inner diameter that Soviet Union's 10-50-54 well uses, more than 150mm, the annular space with described external diameter 99mm insulated tubing can form more than 25mm width, meets this well production requirement and regulation；By operational method under existing well, the insulated tubing of external diameter 99mm can be put into this well internal diameter sleeve pipe more than 150mm.

Calculated from knowledge known in this field: when this well applies technical scheme of the present invention to produce, per diem gas production 24000m³/ day counts, natural gas is risen to the temperature of well head and can reach more than 65 DEG C from this shaft bottom by insulated tubing, exceed the actual measurement wellhead temperature more than 53 DEG C when this well plain tubing produces, be significantly larger than this well 19MPa natural gas hydrate generate critical temperature 21.6 DEG C, it is impossible on oil pipe top, well head generate hydrate.

This well is applied after technical scheme opening well and making production of the present invention, actually detected shows: this well is with being arranged at the oil nozzle in well site according to daily output tolerance 24000～25000m³When controlling/day to produce, it is-24～in the winter low temperature environment of about-27 DEG C at nighttime temperature, it is 69～71 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet, oil pressure 19MPa, casing pressure 20MPa, the most there is not any clogging in the pipeline pipe fitting on oil pipe top, well head (christmas tree)；Stop adding in well mouth oil pipe methanol stopping wellsite heater hot water to well head (christmas tree) tracing thermal-insulating after, this well the most normally produces, up to the experimental period inner oil tube top of 80 days, the pipeline pipe fitting on well head (christmas tree) clogging does not the most occur；After the heat-insulation layer dismounting of this well well head (christmas tree), stopping hotwater tracing, it is-28～in the winter low temperature environment of about-30 DEG C at nighttime temperature, natural gas rises to the temperature of well mouth oil pipe outlet and remains as 69～71 DEG C, does not observes significant change, and gas well liquid loading is normal.

This mill trial results shows: after this well uses technical scheme of the present invention, in annual lowest temperature environment, it is incubated without methanol and hotwater tracing and remains able to guarantee that oil pipe top, well head occur without any Hydrate Plugging, it is able to ensure that this well normally produces, efficiently solves this well and relied on methanol and hotwater tracing to be incubated the difficult problem maintaining production since building up production always；During test, this well is accumulative saves about methanol 4 side, produces methanol poison sewage 52 side less, saves a large amount of dosing expense, and economic benefit and environmental benefit are the most notable.

Embodiment 3

Repeat embodiment 1, it the difference is that only: step 1) in, in order to insulated tubing being put in oil pipe and this oil pipe Wellbore of Gas Wells sleeve pipe already provided with special downhole choke device (such as subsurface choke), the existing oil pipe in gas well and special downhole choke device is replaced: first taken out by the special downhole choke device arranged in oil pipe existing in Wellbore of Gas Wells sleeve pipe and this oil pipe, put in Wellbore of Gas Wells sleeve pipe by insulated tubing with insulated tubing.

Open source information shows: underground work is the mature technology that natural gas produces, the special downhole choke device (such as subsurface choke) arranged in oil pipe in gas well sleeve pipe and this oil pipe can be taken out by the method, and insulated tubing of the present invention is put in gas well sleeve pipe.

As a example by the Soviet Union 11-48-59 well application present invention.

The operational data of Soviet Union's Sulige gas field shows: this well belongs to Soviet Union's Sulige gas field and revives No. 2 existing producing wells of gas gathering station of 11 block, well depth about 3500 meters, shaft bottom natural gas temperature about 110 DEG C, bottom pressure about 20MPa, in using oil pipe, downhole choke method produces, oil pipe used is internal diameter 76mm, external diameter 89mm plain tubing, is provided with special downhole choke device, for throw-in type subsurface choke in oil pipe；Between well site to gas gathering station, the buried gathering line that is not incubated is about 4000 meters, and the buried degree of depth 1.6 meters (freezes 1.5 meters of layer), average annual 9 DEG C of buried ground temperature, minimum ground temperature 5 DEG C；During this well production in summer, the blocking of pit shaft oil pipe top frequently, i.e. adds methanol de-plugging from well head after blocking in oil pipe every time, it is sometimes desirable to repeatedly could release pit shaft blocking for 2～4 times；To this end, this well is taked to be spaced the method periodically adding 50 liters of methanol in oil well oil conduit 1 day, to ensure that gas well normally produces summer；During this well winter production, well head pressure 0.5～0.7MPa, wellhead temperature 6～9 DEG C, instantaneous gas production 600m³/ h (is equivalent to produce tolerance 14400m daily³/ day), aquifer yield 0.7 ton per day.On August 20th, 2010, survey this well casing pressure (suitable with pressure before reducing pressure by regulating flow at the bottom of the natural gas well) 18.8MPa, oil pressure (well mouth oil pipe export gas pressure) 4MPa, instantaneous gas production 500m³/ h (is equivalent to produce tolerance 11000m daily³/ day), aquifer yield 0.5 ton per day, wellhead temperature 9.8 DEG C.

This well uses summer, two kinds of production technologies of winter, its winter production technique can be summarized as: special throttling arrangement (such as the subsurface choke) reducing pressure by regulating flow arranged in first passing through down-hole oil tube from the natural gas of gas-bearing formation is to 0.5～0.7MPa, continue to rise to well head by oil pipe the most again, it is delivered to gas gathering station the most again by buried gathering line between well head, well site surface gathering and transferring pipeline, well site to gas gathering station, to 3～5MPa, the defeated operation of subsequent set is then entered back into subsequently into increase pressure in the compressor that gas gathering station is arranged.Compressor horsepower is 500 kilowatts, drives with combustion gas.

This well production in summer technique can be summarized as: is spaced 1 and adds methanol in gas well oil pipe, special throttling arrangement (such as the subsurface choke) reducing pressure by regulating flow arranged in first passing through down-hole oil tube from the natural gas of gas-bearing formation is to about 4MPa, carry methanol by oil pipe the most again to continue to rise to well head, be delivered to gas gathering station by buried gathering line between well head, well site surface gathering and transferring pipeline, well site to gas gathering station the most again.

Knowledge known in this field calculates and understands: Soviet Union's Sulige gas field gas hydrates critical generation temperature about 10.7 DEG C of pressure 4MPa, therefore temperature when this well natural gas rises to well head, already below hydrate critical generation temperature, necessarily forms this well well head of Hydrate Plugging, oil pipe top.Therefore, if this well prevents hydrate without methanol, will be unable to normally produce.

In order to add, when solving this well production in summer, the variety of problems that methanol brings, reduce gas well management workload degree, guarantee that gas well normally produces, this well applies the present invention to carry out pilot production in November, 2010～in February, 2011, its technical scheme is: first by the method for underground work by the oil pipe of existing external diameter 89mm in Soviet Union's 11-48-59 well shaft sleeve pipe and special downhole choke device (such as the subsurface choke) taking-up of setting in this oil pipe, by the method for underground work, insulated tubing of the present invention is put in this well shaft sleeve pipe the most again, then this well shaft bottom natural gas is allowed to rise to well head by insulated tubing by existing method；Described insulated tubing external diameter 99mm, makes with internal diameter 76mm, external diameter 89mm oil pipe and existing method, and inwall does not has undercoating, outer wall to have the glass fibre reinforced plastic insulation layer of thickness 5mm, heat conductivity 0.4W/m.K.

Calculated from knowledge known in this field and Soviet Union's Sulige gas field operational data: the casing inner diameter that Soviet Union's 11-48-59 well uses, more than 150mm, the annular space with described external diameter 99mm insulated tubing can form more than 25 width, meets this well production requirement and regulation；By operational method under existing well, the insulated tubing of external diameter 99mm can be put into this well internal diameter sleeve pipe more than 150mm.

Calculated from knowledge known in this field: when this well applies technical scheme of the present invention to produce, per diem gas production 14400m³/ day counts, natural gas is risen to the temperature of well head and can reach more than 65 DEG C from this shaft bottom by insulated tubing, exceed the actual measurement wellhead temperature more than 54 DEG C when this well plain tubing produces, be significantly larger than this well 4MPa natural gas hydrate generate critical temperature 10.7 DEG C, it is impossible on oil pipe top, well head generate hydrate.

This well is applied after technical scheme opening well and making production of the present invention, actually detected shows: this well is with being arranged at the oil nozzle in well site according to daily output tolerance 14400m³When controlling/day to produce, casing pressure 18MPa, oil pressure 15MPa, it is-22～in the winter low temperature environment of about-28 DEG C at nighttime temperature, it is 64～66 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet, and any clogging does not the most occur in the pipeline pipe fitting on oil pipe top, well head (christmas tree)；Stopping adding after methanol in well mouth oil pipe, this well the most normally produces, up to the experimental period inner oil tube top of 90 days, the pipeline pipe fitting on well head (christmas tree) clogging does not the most occur；After being removed the heat-insulation layer of this well well head (christmas tree), being-25～in the winter low temperature environment of about-30 DEG C at nighttime temperature, natural gas rises to the temperature of well mouth oil pipe outlet still at 64～66 DEG C, and gas well liquid loading is normal.

Calculated from knowledge known in this field: Soviet Union's Sulige gas field gas hydrates critical generation temperature about 19 DEG C of pressure 15MPa.

This mill trial results shows: after this well uses technical scheme of the present invention, in annual lowest temperature environment, remain able to guarantee that oil pipe top, well head occur without any Hydrate Plugging without methanol, it is able to ensure that this well normally produces, efficiently solves this well and rely on methanol to maintain the difficult problem produced in time having built up production in summer since production always；During test, this well is accumulative saves methanol 2.3 side, produces methanol poison sewage 7 side less many, saves a large amount of dosing expense, and economic benefit and environmental benefit are the most notable.

Embodiment 4

Repeating embodiment 1 to embodiment 3, it the difference is that only:

Described insulated tubing refers to have insulation, thermal insulation, the oil pipe of heat insulation structural (or function).

Described insulated tubing is commodity.

Described insulated tubing inwall has undercoating (such as nature of glass undercoating, pottery undercoating, organic undercoating).

Embodiment 5

Repeating embodiment 1 to embodiment 3, it the difference is that only:

Described insulated tubing is the coiled tubing that vial outer wall (or outside) has heat-insulation layer.

Described coiled tubing is commodity.

Embodiment 6

Repeating embodiment 1 to embodiment 3, embodiment 5, it the difference is that only:

Described insulated tubing refers to have insulation, thermal insulation, the coiled tubing of heat insulation structural (or function).

Described coiled tubing is made by existing method.

Embodiment 7

Repeating embodiment 1 to embodiment 3, it the difference is that only:

Described insulated tubing is the hollow rod that vial outer wall (or outside) has heat-insulation layer.

There is inner via hole at described hollow rod center, it is possible to by fluid, can be any one or two or more combined hollow sucker rod combined of single hole hollow rod, the concentric sucker rod of diplopore, diplopore Factor of Eccentric Rod；Can be the hollow rod of metal material, it is also possible to be the hollow rod of the non-metallic material such as fiberglass, carbon fiber.

Described hollow rod is commodity

Embodiment 8

Repeating embodiment 1 to embodiment 3, embodiment 7, it the difference is that only:

Described insulated tubing refers to have insulation, thermal insulation, the hollow rod of heat insulation structural (or function).

Described hollow rod is made by existing method.

Embodiment 9

Repeating embodiment 1 to embodiment 3, it the difference is that only:

Described insulated tubing is the specialty metal pipe that vial outer wall (or outside) has heat-insulation layer.

Described specialty metal pipe is the metal tube that vial two ends have any non-threaded mechanical connecting structure, as pipe two ends have in flange connection, clamp connection structure, connecting structure for quick coupling any one or the metal tube of two kinds of mechanical connecting structure, its basic feature is to be securely attached to together by two metal tubes.

The effective existing method of described specialty metal is made.

Embodiment 10

Repeating embodiment 1 to embodiment 3, embodiment 9, it the difference is that only:

Described insulated tubing refers to have insulation, thermal insulation, the specialty metal pipe of heat insulation structural (or function).

Described specialty metal pipe is commodity.

Embodiment 11

Repeating embodiment 1 to embodiment 3, it the difference is that only:

Described insulated tubing is the special nonmetal pipe that vial outer wall (or outside) has heat-insulation layer.

Described special nonmetal pipe is the non-metallic pipe that vial two ends have existing machinery attachment structure, and length can be suitable with oil pipe or coiled tubing, it is also possible to up to hundreds of rice；Described existing machinery attachment structure can be any one of the existing mechanical connecting structure of current non-metallic pipe, such as screw nut attachment structure, pipe screw thread pipe collar attachment structure, flange connection, clamp connection structure, connecting structure for quick coupling etc., its basic feature is can be securely attached to together by two non-metallic pipes or by a metal tube, a non-metallic pipe.

Described non-specialty metal pipe is commodity.

Embodiment 12

Repeating embodiment 1 to embodiment 3, embodiment 11, it the difference is that only:

Described insulated tubing refers to have insulation, thermal insulation, the special nonmetal pipe of heat insulation structural (or function).

The effective existing method of described special nonmetal is made.

Embodiment 13

Repeating embodiment 1 to embodiment 3, embodiment 5, embodiment 7, embodiment 9, embodiment 12, it the difference is that only: described insulated tubing is that vial outer wall (or outside) has the oil pipe of heat-insulation layer, coiled tubing, specialty metal pipe, 4 kinds of compound tubes combined of special nonmetal pipe.

Embodiment 14

Repeating embodiment 1 to embodiment 3, embodiment 5, embodiment 7, embodiment 9, embodiment 11, it the difference is that only: described insulated tubing is that vial has insulation, thermal insulation, the oil pipe of heat insulation structural (or function), coiled tubing, specialty metal pipe, 4 kinds of compound tubes combined of special nonmetal pipe.

Embodiment 15

Repeating embodiment 1 to embodiment 5, embodiment 9, it the difference is that only

Described insulated tubing is that vial outer wall (or outside) has the oil pipe of heat-insulation layer, 2 kinds of compound tubes combined of specialty metal pipe.

Embodiment 16

Repeating embodiment 1 to embodiment 5, embodiment 9, embodiment 12, it the difference is that only:

Described insulated tubing is that vial has insulation, thermal insulation, the oil pipe of heat insulation structural (or function), specialty metal pipe, 3 kinds of compound tubes combined of special nonmetal pipe.

Embodiment 17

Repeating embodiment 1 to embodiment 3, it the difference is that only:

Further, described insulated tubing refers to special nonmetal pipe.

From knowledge known in this field: commodity aluminium-plastic pipe belongs to non-metallic pipe, can pressure 10MPa, there is good hardness and flexibility, it is possible to be firmly connected with other non-metallic pipes, metal tube, metal tube by commodity connector, there is the biggest thermal resistance, domestic be commonly used to heating and delivery；Use it for gas well replaces oil pipe, it is possible to effectively reduce natural gas heat loss in Wellbore of Gas Wells, improve natural gas and rise to the temperature of gas well mouth, natural gas even can be allowed to rise to the temperature of well head more than 45 DEG C.Therefore, described special nonmetal pipe replacement oil pipe is put in gas well sleeve pipe, it is possible to function similarly to the effect of oil pipe, it is possible to meet natural gas well production requirement and regulation.Replace oil pipe to put in gas well sleeve pipe 2 or many described special nonmetal pipe parallel connections, the effect of oil pipe can be functioned similarly to equally, disclosure satisfy that natural gas well production requirement and regulation equally；From knowledge known in this field, existing oil pipe specification limit disclosure satisfy that the production needs of all gas wells, generally uses wall scroll oil pipe in gas well sleeve pipe, and in sleeve pipe, the situation of 2 or a plurality of oil pipe used in parallel is the rarest.

Embodiment 18

Repeating embodiment 1, embodiment 4 to embodiment 17, it the difference is that only: step 1) in, in order to insulated tubing being put in Wellbore of Gas Wells oil pipe: external diameter is put in Wellbore of Gas Wells oil pipe less than the insulated tubing of the existing pipe aperture of Wellbore of Gas Wells.

From knowledge known in this field: typically there is oil pipe in gas well sleeve pipe, in the existing oil pipe in gas well sleeve pipe, placing into the oil pipe less than this existing pipe aperture is that natural gas production process, rules and regulations are allowed；The coiled tubing that external diameter is less than pipe aperture is generally put into gas well oil pipe, in order to discharge the aqueous water in Wellbore of Gas Wells by Soviet Union's Sulige gas field；Therefore, external diameter is put into less than the insulated tubing of the existing pipe aperture of Wellbore of Gas Wells Wellbore of Gas Wells oil pipe meets natural gas production requirement and regulation.

As a example by the G48-4A well application present invention.

The operational data in gas field of pacifying the border region shows: this well belongs to the existing producing well of Changqing oilfields the first gas production factory administration, well depth about 3500 meters, shaft bottom natural gas temperature about 110 DEG C, bottom pressure about 20MPa；This well uses external diameter 89mm, the plain tubing of internal diameter 76mm produces, without special downhole choke device in oil pipe, with being arranged at the Special oil nozzle reducing pressure by regulating flow of gas gathering station, adjusting gas production；This well uses the method guarantee production adding methanol with high-pressure pump continuously in pit shaft oil pipe (or sleeve pipe), during winter production, this well adds methanol 400L/ day average every day in well mouth oil pipe (or sleeve pipe), and during production in summer, this well adds 200～300L/ days of methanol average every day in well mouth oil pipe (or sleeve pipe)；On July 8th, 2008, survey this well casing pressure 16MPa, oil pressure 15.4MPa, produce tolerance 20000m daily³/ day, produce water 1 ton per day, wellhead temperature 13.2 DEG C daily；On December 19th, 2008, surveys this well casing pressure 16MPa, oil pressure 14.2MPa, produces tolerance 20000m daily³/ day, produce water 0.6 ton per day, wellhead temperature 8 DEG C daily.

Being calculated from knowledge known in this field: the gas field gas hydrates critical generation temperature about 19.2 DEG C of pacifying the border region of pressure 15.4MPa, the gas hydrates of pressure 14.2MPa generate temperature about 18.8 DEG C.Therefore, this well natural gas wellhead temperature when the summer in winter produces, the most less than hydrate critical generation temperature, necessarily forms Hydrate Plugging this well oil pipe top, well head.Therefore, if this well prevents hydrate without methanol, will be unable to normally produce.

Calculated further from knowledge known in this field: pressure 14.2MPa, natural gas reducing pressure by regulating flow to the temperature of 4MPa of temperature 8 DEG C are-28 DEG C, the running temperature allowed well below natural gas line；Therefore, by this well natural gas, in well site, direct reducing pressure by regulating flow, to 4MPa, is that natural gas produces not permitted in system, technique.

The variety of problems that methanol brings is added in order to solve this well, guarantee that gas well normally produces, this well applies the present invention to carry out pilot production in January, 2009～March, its technical scheme is: first puts in Wellbore of Gas Wells oil pipe by external diameter less than the insulated tubing of the existing pipe aperture of Wellbore of Gas Wells by the method for underground work, allows natural gas rise to well head by this insulated tubing by existing method the most again；Described insulated tubing external diameter 58mm, makes with external diameter 48mm, the oil pipe of internal diameter 34mm and existing method, and inwall does not has undercoating, outer wall to have the glass fibre reinforced plastic insulation layer of thickness 5mm, heat conductivity 0.4W/m.K.

From knowledge known in this field: underground work is the mature technology that natural gas produces, external diameter can be put in Wellbore of Gas Wells oil pipe less than the insulated tubing of the existing pipe aperture of gas well by the method

Calculated from knowledge known in this field: count according to this well daily output tolerance 20,000 mark side/day, pressure 14MPa, insulated tubing internal diameter 34mm, natural gas flow velocity in insulated tubing the largest of about 1.8 meter per second, be that natural gas well production technology, rules and regulations are allowed.

From knowledge known in this field: uniformly wrap up 5mm heavy sheet glass steel heat-insulation layer by existing method at the oil-pipe external wall of external diameter 48mm, internal diameter 34mm and just can make the insulated tubing that external diameter is 58mm, its external diameter now uses pipe aperture 18mm less than 616-17 well, existing with this well can form the wide annular space of 9mm with oil pipe；The pipe with small pipe diameter insulated tubing that external diameter is 58mm can be put in the plain tubing that the existing internal diameter of this well is 76mm by the method for underground work, and the annular space of formed 9mm.

Calculated from knowledge known in this field: when this well applies technical scheme of the present invention to produce, per diem gas production 20000m³/ day counts, the temperature that natural gas rises to well head from this shaft bottom by pipe with small pipe diameter insulated tubing can reach more than 65 DEG C, exceed the actual measurement wellhead temperature more than 51 DEG C when this well plain tubing produces, be significantly larger than this well 15.4MPa natural gas hydrate generate critical temperature 19.2 DEG C, it is impossible on oil pipe top, well head generate hydrate.

This well is applied after technical scheme opening well and making production of the present invention, actually detected shows: this well is with being arranged at the Special oil nozzle of gas gathering station according to daily output tolerance 20000m³When controlling/day to produce, casing pressure 16MPa, oil pressure 15MPa, it is-20～in the winter low temperature environment of about-29 DEG C at nighttime temperature, it is 72～74 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet, and any clogging does not the most occur in the pipeline pipe fitting on oil pipe top, well head (christmas tree)；Stopping adding after methanol in well mouth oil pipe, this well the most normally produces, up to the experimental period inner oil tube top of 70 days, the pipeline pipe fitting on well head (christmas tree) clogging does not the most occur；After being incubated with felt by this well well head (christmas tree), being-20～in the winter low temperature environment of about-29 DEG C at nighttime temperature, it is 73～74 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet, and well head heat insulation effect is notable, and gas well liquid loading is normal.

This mill trial results shows: after this well uses technical scheme of the present invention, in annual lowest temperature environment, remain able to guarantee that oil pipe top, well head occur without any Hydrate Plugging without methanol, it is able to ensure that this well normally produces, efficiently solves this well and relied on methanol to maintain the difficult problem produced since building up production always；During test, this well is accumulative saves methanol 28 side, produces methanol poison sewage 70 side less, and economic benefit and environmental benefit are the most notable.

Embodiment 19

Repeating embodiment 1, embodiment 4 to embodiment 17, it the difference is that only:

Step 1) in, in order to insulated tubing being put in the Wellbore of Gas Wells oil pipe already provided with special downhole choke device (such as subsurface choke): first the special downhole choke device (such as subsurface choke) of Wellbore of Gas Wells oil pipe is taken out, the most again external diameter is put in Wellbore of Gas Wells oil pipe less than the insulated tubing of the existing pipe aperture of Wellbore of Gas Wells.

Implement 20

A kind of natural gas production method, comprises the steps:

2), natural gas is allowed to rise to well head by insulated tubing.

3), natural gas is allowed to rely on own temperature reducing pressure by regulating flow in well site, to reduce natural gas energy consumption.

4), the natural gas after reducing pressure by regulating flow is delivered to gas gathering station.

Described reducing pressure by regulating flow refers to well site surface throttling blood pressure lowering；The surface throttling blood pressure lowering of described well site refers to utilize and is arranged on well site private section fluid element (such as oil nozzle) on the ground or/and gas pressure pipe fitting (such as needle valve) reduction gas pressure can effectively be reduced；Described reducing pressure by regulating flow is one-level (the most disposable) reducing pressure by regulating flow.

Described insulated tubing can allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate or/and natural gas temperature after well site relies on own temperature reducing pressure by regulating flow can be allowed to be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C, should be able to put in Wellbore of Gas Wells sleeve pipe or in oil pipe by existing method, meet gas well liquid loading requirement and regulation.

Described reducing pressure by regulating flow can reduce natural gas energy consumption and cost, can meet the production requirement of natural gas well site and regulation, can meet the gas gathering station production requirement of natural gas and regulation to entering this station.

From knowledge known in this field: natural gas, when well site reducing pressure by regulating flow, generally completes with Special oil nozzle, needle valve, special choke valve, have also completes with other pipe fitting such as reducer pipes, orifice plate, valve etc. that can effectively reduce gas pressure；Commonly use and be arranged at the special pipe fitting on ground, well site, valve group reducing pressure by regulating flow, through frequently with the method at the upper reducing pressure by regulating flow of well head (christmas tree)；The commonly used method well head (christmas tree) or the disposable reducing pressure by regulating flow of surface valve group (throttling also known as one-level), the method being also adopted by and/or surface valve group secondary upper at well head (christmas tree) or repeatedly reducing pressure by regulating flow (also known as two grades or multi-level throttle) having.

From knowledge known in this field: Soviet Union's Sulige gas field, gas field of pacifying the border region, Yulin Gas Field, the natural gas purification processing factory commonly used propane deep cooling dewatering of DaNiuDi gas field reduce gas dew point, the method is to be cooled by natural gas to-8 DEG C of dehydrations (will gas dew point be down to-8 DEG C), typically require that the natural gas temperature that gas gathering station enters purifying plant is-8～18 DEG C, in the range of-8～18 DEG C, the natural gas temperature that gas gathering station enters purifying plant is the lowest, and energy, cost that purifying plant is consumed are the lowest；In natural gas winter production, the natural gas temperature entering gas gathering station is that production technology, rules and regulations are allowed less than 0 DEG C, and is a kind of common phenomenon.

From knowledge known in this field: natural gas production requirement and regulation: the minimum operating temperature of natural gas line is not less than-20 DEG C.

As a example by the Soviet Union Sulige gas field Su10 Block Soviet Union 10-50-54 well application present invention.

Open source information shows: Su10 Block belongs to Soviet Union's Sulige gas field, is positioned at Ordos, inner Mongolia desert area, and winter minimum temperature reaches-31 DEG C.

The operational data of Su10 Block shows: this block natural gas well average well depth about 3500 meters, shaft bottom gas-bearing formation temperature about 110 DEG C, general daily output tolerance 1～50,000 mark side/day, gas well all uses plain tubing, sleeve structure, oil pipe used, sleeve pipe are metal blank tubing, and down-hole is without reducing pressure by regulating flow device.Actual measurement gas well mouth oil pipe outlet pressure in winter is 18～20MPa, and actual measurement well head in winter is 9～30 DEG C without natural gas temperature during heat tracing.Well head is 500～ten thousand metres to the defeated distance of collection (also known as collecting defeated radius) of gas gathering station, gathering line is yellow jacket polyurethane foam insulation layer insulation, design the buried degree of depth 1.6 meters (freezing 1.5 meters of layer), surveying 1.6 meter layer year-round average temperature is 9 DEG C, and winter minimum temperature is less than 5 DEG C.

This block uses well site to add thermal throttle production technology: natural gas rises to the well head being incubated by hotwater tracing by oil pipe, it is heated to about 70 DEG C subsequently into the heating furnace being arranged at well site, subsequently into utilizing the disposable reducing pressure by regulating flow of Special oil nozzle to about 4MPa in the surface gathering and transferring valve group of well site, then the buried gathering line by being incubated with yellow jacket polyurethane foam insulation layer is delivered to gas gathering station.

From knowledge known in this field calculate: pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 10 DEG C to 4MPa time, its temperature will drop to-47.5 DEG C.Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 20 DEG C to 4MPa time, its temperature will drop to-37.5 DEG C.Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 30 DEG C to 4MPa time, its temperature will drop to-27.8 DEG C.Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 40 DEG C to 4MPa time, its temperature will drop to-16 DEG C.Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 50 DEG C to 4MPa time, its temperature will drop to-2.9 DEG C.Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 60 DEG C to 4MPa time, its temperature will drop to 10.2 DEG C.Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 70 DEG C to 4MPa time, its temperature will drop to 23.1 DEG C.Pressure is 20MPa, temperature be Soviet Union's Sulige gas field natural gas reducing pressure by regulating flow of 80 DEG C to 4MPa time, its temperature will drop to 35.9 DEG C

Calculated from knowledge known in this field: pressure is that to generate critical temperature be 22.1 DEG C for the Soviet Union Sulige gas field gas hydrates of 20MPa, pressure be Soviet Union's Sulige gas field gas hydrates generation critical temperature of 4MPa be 10.7 DEG C.Therefore, Soviet Union's Sulige gas field natural gas that well head pressure is 20MPa, wellhead temperature is 9～22.1 DEG C can form hydrate at pit shaft, well head, blocks gas well.Although Soviet Union's Sulige gas field natural gas that well head pressure is 20MPa, wellhead temperature is 30 DEG C will not form hydrate at pit shaft, well head, but when by its pressure by 20MPa reducing pressure by regulating flow to 4MPa, its temperature can be down to-27.8 DEG C, the minimum use temperature-20 DEG C allowed well below natural gas line, is that natural gas produces not permitted in rules and regulations.

Therefore, if a part of gas well of Su10 Block is not taked to add methanol or the method being incubated well head without hotwater tracing in well, Hydrate Plugging gas well will be generated on well head, oil pipe top；The natural gas that all gas wells of this block are produced is when well site reducing pressure by regulating flow, if the heating furnace not first passing through well site setting before reducing pressure by regulating flow is heated to more than 60 DEG C, but from well head out rear directly reducing pressure by regulating flow, not only can necessarily generate gas hydrates, ice in Special oil nozzle (restricting element), gathering line, pipe fitting, and the minimum use temperature-20 DEG C that natural gas temperature is far below Special oil nozzle (restricting element), natural gas line, pipe fitting are allowed can be made, it is that natural gas produces not permitted in rules and regulations.

The all production problems manually adding methanol to OIH pipe, gas well mouth needs tracing thermal-insulating, natural gas must first be brought with heating furnace heat temperature raising before the reducing pressure by regulating flow of well site to solve Su10 Block to need, save energy consumption and production cost, reduce gas well management workload, guaranteeing that gas well normally produces, this block has carried out pilot production in Decembers, 2008～in February, 2009 in the Soviet Union 10-50-54 well application present invention.

The operational data of Soviet Union's Sulige gas field shows: Soviet Union's 10-50-54 well belongs to Soviet Union's existing producing well of Sulige gas field Su10 Block, well depth about 3500 meters, shaft bottom natural gas temperature about 110 DEG C, bottom pressure about 20MPa, employing oil pipe produces, oil pipe used is external diameter 89mm, internal diameter 76mm plain tubing, without special downhole choke device in oil pipe, uses Special oil nozzle reducing pressure by regulating flow again, adjusts gas production after using the heating furnace heated natural gas being arranged at well site；When this well produces, the blocking of pit shaft oil pipe top frequently, every time after blocking i.e. with manually from well head to the method de-plugging adding methanol in oil pipe, it is sometimes desirable to repeatedly could release pit shaft for 2～4 times and block；To this end, the method manually adding 50 liters of methanol in oil well oil conduit every day taked by this well, and prevent oil pipe top from generating hydrate with the hot water of wellsite heater to the method for well head tracing thermal-insulating, it is ensured that gas well normally produces.On October 10th, 2008, survey this well casing pressure (suitable with pressure before reducing pressure by regulating flow at the bottom of the natural gas well) 20MPa, oil pressure (well mouth oil pipe export gas pressure) 19MPa, instantaneous gas production 1000m³/ h (is equivalent to produce tolerance 24000m daily³/ day), wellhead temperature 12 DEG C, aquifer yield 0.4～0.6m³/ day.

The production technology of this well can be summarized as: after this well natural gas rises to well head by oil pipe, it is introduced in being arranged at the heating furnace in well site and is heated to 65～70 DEG C, the disposable reducing pressure by regulating flow of Special oil nozzle arranged by ground, well site the most again is delivered to gas gathering station to about 4MPa, the 3200 meters of buried insulation gathering lines being incubated with yellow jacket polyurethane foam insulation layer the most again.

Calculated from knowledge known in this field: Soviet Union's Sulige gas field gas hydrates critical generation temperature about 21.6 DEG C of pressure 19MPa, therefore the temperature 12 DEG C when this well natural gas rises to well head, already below hydrate critical generation temperature, necessarily forms this well well head of Hydrate Plugging, oil pipe top.Therefore, if this well prevents hydrate from producing without methanol, will be unable to normally produce；Calculate further and understand, if this well rises to the 19MPa of well head, the natural gas of 12 DEG C by the heating furnace heat temperature raising i.e. reducing pressure by regulating flow in well site to 4MPa, temperature during its reducing pressure by regulating flow will drop to less than-41 DEG C, the minimum use temperature-20 DEG C allowed well below Special oil nozzle, natural gas line, pipe fitting, is that natural gas produces not permitted in rules and regulations.

This well application present invention carries out the technical scheme of pilot production: first with operational method under existing well by this casing plain tubing take out from sleeve pipe；By operational method under existing well, insulated tubing is put into this casing the most again, allow natural gas rise to well head by insulated tubing；Then allow well head gas utilization bypass line out cross the existing heating furnace being arranged at well site, rely on own temperature by disposable (i.e. one-level) reducing pressure by regulating flow of the existing Special oil nozzle being arranged at ground, well site to 4MPa；It is delivered to gas gathering station the most again with the buried insulation gathering line of existing yellow jacket polyurethane foam insulation layer insulation.Described insulated tubing external diameter 99mm, makes with external diameter 89mm, internal diameter 76mm oil pipe and existing method, does not has undercoating, outer wall to have thickness 5mm, heat conductivity to be 0.4W/m.K glass fibre reinforced plastic insulation layer.

Calculated from knowledge known in this field: after the Soviet Union 10-50-54 well application present invention, this well oil pipe is insulated tubing, averagely producing tolerance daily according to this well is 24000 mark sides/day, oil pressure 20MPa calculating, the temperature that natural gas rises to well head by insulated tubing can reach more than 65 DEG C, being far above the gas hydrates critical generation temperature of this well pressure 20MPa, the temperature after heating with existing wellsite heater with this gas well institute producing natural gas is suitable；Calculate further and understand: by produced for this well pressure be 20MPa, temperature be the natural gas of 65 DEG C in well site direct reducing pressure by regulating flow to temperature during 4MPa about 16 DEG C, remaining above the gas hydrates that pressure is 4MPa and generate critical temperature 10.7 DEG C, therefore this well will not form Hydrate Plugging when well site reducing pressure by regulating flow；Further calculate and understand: according to the existing buried gathering line of this well be Huang jacket polyurethane foam insulation layer hot insulated line, design the actual measurement year-round average temperature of the buried degree of depth 1.6 meters (freezing 1.5 meters of layer) and be 9 DEG C, the defeated distance of collection in well site to gas gathering station is 3200 meters of calculating, temperature when this well 16 DEG C of natural gass after the reducing pressure by regulating flow of well site are delivered to gas gathering station from well site is about 13 DEG C, remains above the gas hydrates that pressure is 4MPa and generates critical temperature 10.7 DEG C.Therefore, after this well application present invention, natural gas temperature before the reducing pressure by regulating flow of well site has been up to 65 DEG C, it is no longer necessary to heating furnace heat temperature raising, not only can not on oil pipe top, well head generate hydrate, hydrate will not be generated when well site reducing pressure by regulating flow, also between well site to gas gathering station, hydrate in buried insulation gathering line, will not be generated, pipeline, pipe fitting more will not be made to run under-20 DEG C of low temperature environments, be fully able to rely on this well pressure itself, temperature and existing hot insulated line to enter gas gathering station smoothly.

It can thus be appreciated that, after the Soviet Union 10-50-54 well application present invention, it is no longer necessary in gas well oil pipe, add methanol every day, it is no longer necessary to hot water to well head tracing thermal-insulating, institute's producing natural gas need not heat the production requirement having reached 65～70 DEG C by existing wellsite heater, met the requirement at well site reducing pressure by regulating flow of this well natural gas and the defeated requirement of collection of well site to gas gathering station, thus efficiently solve this well use methanol in well site and use existing heating furnace and cause power consumption, the defect such as environmental pollution.

Open source information shows: tank oil tubing matter is generally N80 steel, and the heat conductivity of N80 steel is about about 50W/m.K；The heat conductivity of commercial glasses steel part about about 0.39W/m.K, can make the glass fibre reinforced plastic insulation layer of heat conductivity 0.4W/m.K by existing method.

Open source information shows: use existing method, it is possible to plain tubing is made glass fibre reinforced plastic insulation layer thickness 5mm, the heat conductivity insulated tubing less than 0.4W/m.K, and disclosure satisfy that gas well liquid loading requirement；Liaohe Oil Field once in crude oil with high solidifying point oil well production large scale experiment applied such glass fibre reinforced plastic insulation oil pipe.

Calculated from knowledge known in this field and Soviet Union's Sulige gas field operational data: the casing inner diameter that Soviet Union's 10-50-54 well uses, more than 150mm, the annular space with described external diameter 99mm insulated tubing can form more than width 25mm, meets this well production requirement and regulation；By operational method under existing well, the insulated tubing of external diameter 99mm can be put into this well internal diameter sleeve pipe more than 150mm.

This well is applied after technical scheme opening well and making production of the present invention, actually detected shows: this well is with being arranged at the Special oil nozzle of well site surface valve group according to daily output tolerance 24000m³When controlling/day to produce, casing pressure 20MPa, oil pressure 19.4MPa, it is-24～in the winter low temperature environment of-27 DEG C at nighttime temperature, stopping adding methanol, stoppage in transit wellsite heater, stopping in well mouth oil pipe with wellsite heater hot water to well head (christmas tree) tracing thermal-insulating, it is 69～71 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet；This well institute producing natural gas is allowed to be crossed after heating furnace directly at well site reducing pressure by regulating flow to 4MPa by bypass line, temperature after its reducing pressure by regulating flow is 24～26 DEG C, it is 19～21 DEG C that natural gas enters the temperature of gas gathering station, any clogging does not the most occur at the buried heat insulation pipe line up between experiment periods inner oil tube top, well head (christmas tree), well site surface line pipe fitting and well site to the gas gathering station of 80 days；After further the heat-insulation layer of this well well head (christmas tree) being removed, it is-28～in the winter low temperature environment of-30 DEG C at nighttime temperature, it is 69～71 DEG C that this well natural gas rises to the temperature of well mouth oil pipe outlet, temperature after its reducing pressure by regulating flow is 24～25 DEG C, it is 19～21 DEG C that natural gas enters the temperature of gas gathering station, all not observing significant change, the most there is not clogging in all pipeline pipe fittings between oil pipe top to gas gathering station.

This mill trial results shows: after this well uses technical scheme of the present invention, in annual lowest temperature environment, without methanol, it is incubated well head without hotwater tracing to remain able to guarantee oil pipe top, well head occurs without any Hydrate Plugging, before noting be used in reducing pressure by regulating flow, heat temperature raising is able to ensure that well site pipeline pipe fitting, between well site to gas gathering station, buried gathering line does not generate hydrate, ice, it is able to ensure that gas well and gathering system thereof normally produce, efficiently solve this well since building up production, rely on methanol always, wellsite heater heating and hotwater tracing are incubated and maintain the difficult problem produced；During test, this well is accumulative saves about methanol 4 side, produce methanol poison sewage 52 side less, save ten thousand stere on heating furnace natural gas, save a large amount of dosing expense and heating furnace operation and maintenance cost, also can save the fixed investment expense of lower 1 heating furnace, economic benefit and environmental benefit are the most notable.

Embodiment 21

Repeating embodiment 20, it the difference is that only:

Described reducing pressure by regulating flow refers to well head reducing pressure by regulating flow；Described well head reducing pressure by regulating flow refers to utilize and is arranged on the private section fluid element (such as oil nozzle) of well mouth oil pipe outlet or/and the pipe fitting (such as needle valve) that can effectively reduce gas pressure reduces gas pressure；Described reducing pressure by regulating flow is more than 2 grades reducing pressure by regulating flows.

Embodiment 22

Repeating embodiment 20, it the difference is that only:

Step 3) in, in order to generate hydrate, ice in preventing natural gas pipeline pipe fitting when well site reducing pressure by regulating flow and after reducing pressure by regulating flow: first add antifreezing agent in natural gas, allow the natural gas carrying antifreezing agent rely on own temperature at well site reducing pressure by regulating flow the most again.

Described antifreezing agent meets natural gas production requirement and regulation, can ensure that natural gas cannot form hydrate, ice when well site reducing pressure by regulating flow；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

Described reducing pressure by regulating flow meets natural gas production requirement and regulation；As those of ordinary skill in the art, can determine the concrete scheme of described first time reducing pressure by regulating flow, throttle style, restricting element, Restriction Parameters, maximum reducing pressure by regulating flow pressure and temperature, minimum reducing pressure by regulating flow pressure and temperature, optimal reducing pressure by regulating flow pressure and temperature by existing method.

From knowledge known in this field and calculation of thermodynamics: in natural gas produces, the gas deliverability of different gas wells may be different, and some gas well gas production are high, and some gas well gas production are low.Temperature when natural gas rises to well head from shaft bottom is relevant with gas production (or flow that natural gas is in pit shaft), and under equal conditions, gas production is the least, and the temperature that natural gas arrives well head is the lowest；Therefore, the gas well that gas production is relatively low, the temperature that natural gas rises to well head by insulated tubing of the present invention is relatively low, temperature when well site reducing pressure by regulating flow and after reducing pressure by regulating flow is likely lower than hydrate critical generation temperature, needs to add antifreezing agent before reducing pressure by regulating flow for this and prevents hydrate from generating.

As a example by the Soviet Union 36-13 well application present invention of Soviet Union Sulige gas field Soviet Union 6-1 station.

The Soviet Union 6-1 station means of production for many years show: Soviet Union 6-1 station and Soviet Union's 11 blocks belong to Sulige gas field structure of reviving, administer 23 mouthfuls of natural gas wells, average well depth 3500 meters, shaft bottom natural gas temperature about 110 DEG C, bottom pressure is 15～20MPa, and oil pipe used by gas well is generally external diameter 73mm, internal diameter 62mm plain tubing；Buried gathering line between gas well mouth, well site surface gathering and transferring pipeline pipe fitting, well site to gas gathering station is not incubated, the defeated distance of collection (also known as collecting defeated radius) of well site to gas gathering station is 500～ten thousand metres, the gathering line design buried degree of depth 1.6 meters (freezing 1.5 meters of layer) is below, the buried temperature of actual average 9 DEG C, winter minimum temperature is less than 5 DEG C；Natural gas well head oil pressure is 1～2MPa, and casing pressure is 15～20MPa, wellhead temperature-2～5 DEG C；Winter in 2009, Soviet Union 6-1 station administrative 23 mouthfuls of natural gas well generation Gas well blocking 18 mouthfuls, cumulative effect gas production 83.58 ten thousand side.

The production technology that Soviet Union 6-1 station uses is: special throttling arrangement (such as the subsurface choke) reducing pressure by regulating flow arranged in first passing through down-hole oil tube from the natural gas of gas-bearing formation is to 1～2MPa, continue to rise to well head by oil pipe the most again, order is delivered to gas gathering station by buried gathering line between well head, well site surface gathering and transferring pipeline, well site to gas gathering station the most again, then in the compressor arranged in entering back into gas gathering station, increase pressure is to 4～5MPa, then enters back into the defeated operation of gas gathering station subsequent set and transports to outward purifying plant.The compressor horsepower arranged in gas gathering station is 500 kilowatts, drives with combustion gas.

Being calculated from knowledge known in this field: pressure is the Su Lige natural gas of 0.7MPa, its hydrate generates critical temperature and is-5.45 DEG C；Pressure is the Su Lige natural gas of 1MPa, and its hydrate generates critical temperature and is-1.24 DEG C；Pressure is the Su Lige natural gas of 1.2MPa, and it is 0.23 DEG C that its hydrate generates critical temperature；Pressure is the Su Lige natural gas of 1.5MPa, and it is 2.7 DEG C that its hydrate generates critical temperature；Pressure is the Su Lige natural gas of 2MPa, and it is 5.1 DEG C that its hydrate generates critical temperature；Pressure is the Su Lige natural gas of 2.5MPa, and it is 6.9 DEG C that its hydrate generates critical temperature.Therefore wellhead temperature-1.2～5.1 DEG C, well head pressure 1～2MPa Soviet Union 6-1 station gas well inevitable on oil pipe top, well head generate hydrate, block gas well.

In order to solve revive 6-1 station administered gas well winter production time Hydrate Plugging gas well, pipeline, the problem affecting gas well liquid loading time, gas production, guaranteeing that gas well normally produces, this block has carried out pilot production in January, 2010～in March, 2011 in the Soviet Union 36-13 well application present invention.

The operational data of Soviet Union's Sulige gas field shows: Soviet Union's 36-13 well belongs to the existing producing well of Soviet Union Sulige gas field the 4th gas production factory Soviet Union 6-1 station administration, well depth about 3500 meters, shaft bottom natural gas temperature about 110 DEG C, gas-bearing formation reset pressure about 22MPa, employing oil pipe produces, oil pipe used is external diameter 73mm, internal diameter 62mm plain tubing, is provided with throw-in type subsurface choke in oil pipe；Between gas well mouth, well site surface gathering and transferring pipeline pipe fitting, well site to gas gathering station, buried gathering line is not incubated, between well site to gas gathering station, buried gathering line is about 3800 meters, design the buried degree of depth 1.6 meters (freezing 1.5 meters of layer) below, the actual measurement buried ground temperature of annual 9 DEG C, minimum buried temperature is less than 5 DEG C；There is blocking 5 times to 3 month to dates in this well in November, 2009, stifled position is concentrated mainly on well head, pit shaft oil pipe top, well site surface line pipe fitting；After this well blocks every time, all take to add 200 in oil pipe, surface line～the method de-plugging of 400L methanol.December in 2009 is surveyed this well on the 20th and is used the method guarantee gas well liquid loading adding methanol 150L/ time to oil pipe the next day, average daily output tolerance 0.3 ten thousand mark side/day, well head oil pressure is 1.5MPa, and casing pressure is 14MPa, wellhead temperature-1.5 DEG C, the next day oil pipe add quantity of methyl alcohol 150L/ time.

The production technology of this well can be summarized as: the subsurface choke reducing pressure by regulating flow that shaft bottom natural gas is arranged in first passing through down-hole oil tube is to 1～2MPa, continue to rise to well head by oil pipe the most again, order is delivered to, by buried gathering line between well head, well site surface gathering and transferring pipeline, well site to gas gathering station, 6-1 gas gathering station of reviving the most again, then in the compressor arranged in entering back into 6-1 gas gathering station of Soviet Union, increase pressure is to about 4MPa, transports to purification plant outside then entering back into after 6-1 gas gathering station of the Soviet Union defeated operation of subsequent set processes further.The single compressor power about 500 kilowatts arranged in 6-1 gas gathering station of Soviet Union, drives with combustion gas.

From knowledge known in this field calculate: pressure be 1.2MPa Su Lige gas hydrates generation critical temperature be 0.23 DEG C；Pressure be 1.5MPa Su Lige gas hydrates generate critical temperature be 2.7 DEG C；Pressure be 2MPa Su Lige gas hydrates generate critical temperature be 5.1 DEG C；Pressure be 22MPa Su Lige gas hydrates generate critical temperature be 23 DEG C；Pressure be 4MPa Su Lige gas hydrates generate critical temperature be 10.7 DEG C；Pressure be 14MPa Su Lige gas hydrates generate critical temperature be 18 DEG C；Therefore, the Soviet Union's 36-13 well natural gas of wellhead temperature-1.5 DEG C hydrate already below its 1.5MPa generates critical temperature, inevitable on oil pipe top, well head generate hydrate.Therefore, if this well prevents hydrate from generating without methanol, cannot normally produce in the winter time.

Calculated further from knowledge known in this field: if this well does not use downhole choke production method, its natural gas rises to the maximum pressure of well head still less than casing pressure 14MPa, according to well head pressure and casing pressure 14MPa, wellhead temperature 5 DEG C calculating at once mutually, it is by temperature during 14MPa reducing pressure by regulating flow to 4MPa about-31 DEG C, it is far below the minimum operating temperature that natural gas line is allowed, has been not permitted in production technology, rules and regulations；Therefore, when this well is without downhole choke blood pressure lowering, in well site or gas gathering station, before reducing pressure by regulating flow, must first use heating furnace heat temperature raising.

This well application present invention carries out the concrete technical scheme of pilot production:

1), first with operational method under existing well by Soviet Union 36-13 well shaft sleeve pipe in external diameter 73mm oil pipe and this oil pipe in arrange subsurface choke take out；

2), then by operational method under existing well, insulated tubing is put in Soviet Union's 36-13 well shaft sleeve pipe；Described insulated tubing external diameter 100mm, make with external diameter 73mm, internal diameter 62mm oil pipe and existing method, inwall has 0.2mm organic matter undercoating, and outer wall has thickness 0.5mm, heat conductivity 0.03W/m.K heat insulating coatings and thickness 13mm, the glass fibre reinforced plastic composite heat-insulating layer of heat conductivity 0.4W/m.K；

3), natural gas is allowed to rise to well head by insulated tubing by existing method the most again；

4), then first pass through gas well outlet line to add in natural gas and press down ice agent liquid, allow the most again carry and press down the natural gas of ice agent liquid and rely on own temperature by being arranged on the oil nozzle reducing pressure by regulating flow of well site surface valve group to 4MPa；Described press down that any one described in " natural gas exploiting method of a kind of cleaning " file that ice agent liquid is number of patent application 2009101436712 is optional presses down ice agent liquid.；

5) natural gas is delivered to this gas gathering station by buried not hot insulated line between 6-1 gas gathering station of extremely reviving, the most again with existing well site, and crosses compressor entrance subsequent treatment operation by bypass line in this gas gathering station.

Open source information shows: can make outer wall by oil pipe and existing method has thickness 0.5mm, heat conductivity 0.03W/m.K heat insulating coatings and thickness 13mm, the insulated tubing of heat conductivity 0.4W/m.K glass fibre reinforced plastic composite heat-insulating layer；The heat conductivity of commodity heat insulating coatings about 0.03W/m.K.

Calculated from knowledge known in this field: Soviet Union's 36-13 well uses 7 inches of sleeve pipes, and internal diameter is more than 150mm, described insulated tubing external diameter 100mm, therefore, it is possible to form the annular space of more than width 25mm with sleeve pipe, meets gas well liquid loading requirement and regulation；The insulated tubing of external diameter 100mm can be put into this casing by operational method under existing well.

From knowledge known in this field and calculation of thermodynamics: if Soviet Union's 36-13 well uses technical scheme of the present invention to carry out winter production, tolerance 3000 sides/day, shaft bottom natural gas temperature 110 DEG C calculating is averagely produced daily according to gas well, the temperature that natural gas rises to well head from shaft bottom by insulated tubing of the present invention can reach more than 40 DEG C, exceed the existing plain tubing of this well and carry out the minimum actual measurement wellhead temperature more than 41 DEG C of winter production, be significantly larger than this well 22MPa gas-bearing formation reset pressure, the hydrate of 14MPa casing pressure generates critical temperature；Owing to gas well casing pressure is always higher than oil pressure, therefore the natural gas of this well wellhead temperature 40 DEG C can not on oil pipe top, well head formed Hydrate Plugging.

But, after the Soviet Union 36-13 well application present invention, in this well shaft oil pipe, there is no subsurface choke reducing pressure by regulating flow, natural gas rises to the maximum pressure of well head will be slightly below this well casing pressure 14MPa.

Calculated further from knowledge known in this field: pressure is 14MPa, temperature be this well natural gas of 40 DEG C when well site reducing pressure by regulating flow to 4MPa, its temperature is about 5 DEG C, generates temperature already below hydrate that this well pressure is 4MPa；Therefore, after the Soviet Union 36-13 well application present invention, natural gas will not generate hydrate at this well shaft, well head, but can generate hydrate when this well well site reducing pressure by regulating flow.

From open source information " natural gas exploiting method of a kind of cleaning " file of 2009101436712 (number of patent application be): press down ice agent liquid and be prevented from hydrate 5 DEG C of generations, it is possible to effectively melt 5 DEG C of gas hydrates formed.

From knowledge known in this field: the minimum permission cryogenic operating temperatures of natural gas line is-20 DEG C；Therefore, although when 36-13 well natural gas of reviving in well site by 14MPa reducing pressure by regulating flow to 4MPa time can generate hydrate, but without causing this well natural gas line running temperature less than minimum permission running temperature, be that natural gas production process, rules and regulations are allowed.

From knowledge known in this field: owing to the gathering line between 36-13 well well site to gas gathering station of Soviet Union is not for be incubated buried pipeline, average buried temperature 9 DEG C, natural gas temperature after well site throttles is 5 DEG C, therefore it can heat up from the earth heat absorption during being delivered to gas gathering station by buried gathering line, temperature when entering 6-1 gas gathering station of Soviet Union will be above 5 DEG C, is that gas gathering station production technology, rules and regulations are allowed.

From knowledge known in this field: Soviet Union's Sulige gas field, gas field of pacifying the border region, Yulin Gas Field, the natural gas purification processing factory commonly used propane deep cooling dewatering of DaNiuDi gas field reduce gas dew point, the method is that natural gas is refrigerated to-8 DEG C (will gas dew point be down to-8 DEG C), typically require that the natural gas temperature that gas gathering station enters purifying plant is-8～18 DEG C, in the range of-8～18 DEG C, the natural gas temperature that gas gathering station enters purifying plant is the lowest, and energy, cost that purifying plant is consumed are the lowest；In this gas field winter production, the natural gas temperature entering gas gathering station is that this gas field production technology, rules and regulations are allowed, and are the common phenomena in this gas field less than 5 DEG C.

Therefore, after technical scheme of the present invention applied by Soviet Union's 36-13 well, not only ensure that this well normally produces winter without methanol and other antifreezing agents, and after addition presses down ice agent liquid, it is able to ensure that this well institute producing natural gas just can be at this direct reducing pressure by regulating flow in well well site to 4MPa without heat temperature raising, be able to ensure that its with 4MPa pressure be delivered to revive 6-1 gas gathering station time do not generate hydrate and this gas gathering station inner compressor can be crossed be directly entered subsequent treatment operation, therefore, it is possible to avoid this well to use methanol in well site, use in 6-1 gas gathering station of Soviet Union and consume energy produced by compressor boost, the defects such as pollution.

Soviet Union's 36-13 well is applied after technical scheme opening well and making production of the present invention, actually detected shows: this well is with being arranged at the Special oil nozzle of well site surface valve group according to daily output tolerance 3000m³When controlling/day to produce, casing pressure 14MPa, oil pressure 13.5MPa, be-24～in the winter low temperature environment of-27 DEG C at nighttime temperature, and it is 42～43 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet；Well head 42～43 DEG C of natural gas straights out were connected well site surface valve group oil nozzle reducing pressure by regulating flow will block in 1 hour to the oil nozzle that throttles during 4MPa, throttling rear tubular member valve, it is impossible to normally produce；After in natural gas, addition presses down ice agent liquid 50L/ day, allowing natural gas again is 6～6.5 DEG C by the temperature after well site surface valve group oil nozzle reducing pressure by regulating flow to 4MPa, by buried be not incubated gathering line enter Soviet Union 6-1 gas gathering station temperature be 8～9 DEG C, pressure is 3.5～3.7MPa.

This mill trial results shows: after technical scheme of the present invention applied by Soviet Union's 36-13 well, and in annual lowest temperature environment, any clogging the most do not occur in this well well head, oil pipe top；When employing is not added with pressing down ice agent liquid 50L/ day reducing pressure by regulating flow method test can quickly frozen block throttling oil nozzle, pipe fitting, valve, need to throttling oil nozzle in add press down ice agent liquid or with hot water heating ability de-plugging；And when use first add the method test pressing down reducing pressure by regulating flow again after ice agent liquid 50L/ day time, not only between well site pipeline pipe fitting, well site to gas gathering station, the most there is not any clogging in buried gathering line, and this well natural gas can be made just to meet this gas gathering station subsequent handling without 6-1 gas gathering station of Soviet Union compressor boost and process and transport to outward the requirement of purification plant, thus efficiently solve this well and relied on methanol to maintain the defects such as gas well liquid loading, the outer defeated pollution of inner compressor supercharging of 6-1 gas gathering station of the Soviet Union of dependence always, power consumption since building up production always.During test, this well is accumulative saves methanol 6 side, also saves big capacity compressor natural gas, and economic benefit and environmental benefit are the most notable.

Embodiment 23

Repeating embodiment 20, embodiment 22, it the difference is that only:

Step 3) in, in order to utilize big geothermal energy to reduce the antifreezing agent consumption that natural gas dependence own temperature is required when well site reducing pressure by regulating flow: first add antifreezing agent in natural gas；The natural gas carrying antifreezing agent is allowed to rely on own temperature and underground heat repeatedly reducing pressure by regulating flow in buried gathering line between well site to gas gathering station the most again, in order to allow natural gas pass through buried gathering line and heat up from the earth heat absorption.

Described repeatedly reducing pressure by regulating flow refers between well site to gas gathering station the reducing pressure by regulating flow of any more than 2 positions on buried gathering line, may refer to the reducing pressure by regulating flow utilizing proprietary restricting element (such as flow limit method) to carry out, it is also possible to refer to utilize reducer pipe, orifice plate, valve etc. can effectively reduce the reducing pressure by regulating flow that the pipe fitting of gas pressure is carried out.

Described repeatedly reducing pressure by regulating flow meets natural gas production requirement and regulation, big geothermal energy can be utilized to reduce antifreezing agent consumption, big geothermal energy can be utilized to allow the temperature of natural gas in-line be higher than 0 DEG C and less than gathering line buried annual low temperature between well site to gas gathering station or less than 10 DEG C.As those of ordinary skill in the art, with existing method can determine described in the repeatedly concrete scheme of reducing pressure by regulating flow, throttle style, restricting element, Restriction Parameters, maximum reducing pressure by regulating flow pressure and temperature, minimum reducing pressure by regulating flow pressure and temperature, optimal reducing pressure by regulating flow pressure and temperature.

With Sulige gas field gas production 1000m of reviving³As a example by/day new well application the present invention.

From knowledge known in this field: Soviet Union's Sulige gas field belongs to Recover of Tight Sandstone Gas Reservoir, gas-bearing formation buried depth is typically at about 3500 meters, gas-bearing formation is divided into I class, II class, Group III gas-bearing formation according to permeability height, wherein II class, Group III gas-bearing formation gas well gas production relatively low, some gas well gas production are less than 1000m³/ day.

From knowledge known in this field: the gas pressure in gas well shaft bottom and gas well gas production do not have positive causal relationship, and have positive causal relationship with gas-bearing formation buried depth.Gas production is less than 1000m³When the gas well gas-bearing formation buried depth of/day is 3500 meters, its gas-bearing formation reset pressure is still about 22MPa, and therefore Soviet Union's Sulige gas field gas production is less than 1000m³The gas well mouth pressure of/day up to more than 20MPa, bottom hole temperature (BHT) up to 110 DEG C.

From Sulige gas field Soviet Union of Soviet Union 36-13 well operational data: this gas well gas layer buried depth 3500 meters, reset pressure 20MPa, bottom hole temperature (BHT) about 110 DEG C, existing gas production 3000m³/ day, casing pressure 14MPa, use downhole choke method to produce, there is blocking 5 times to 3 month to dates in November, 2009, stifled position is concentrated mainly on well head, pit shaft oil pipe top, well site surface line pipe fitting；After this well blocks every time, all take to add 200 in oil pipe, surface line～the method de-plugging of 400L methanol.

From knowledge known in this field: gas well gas production is the lowest, the temperature that natural gas rises to well head is the lowest, and therefore Soviet Union's new well of Sulige gas field low yield equally exists the variety of problems of existing similar Soviet Union 36-13 well when high-yield well produces.

In order to avoid use when the new well of Su Lige low yield produces methanol, downhole choke dropping equipment, in gas gathering station compressor boost or must be first to defects such as heated by natural gas before well site gas gathering station reducing pressure by regulating flow, the new well in this gas field can apply the present invention, and its technical scheme is:

1), during the new well construction in this gas field, first by existing method, insulated tubing is put in sleeve pipe, allow natural gas rise to well head by insulated tubing by existing method the most again；Described insulated tubing external diameter 90mm, makes with external diameter 48mm, internal diameter 34mm oil pipe and existing method, and inwall does not has undercoating, outer wall to have the glass fibre reinforced plastic insulation layer of thickness 21mm, heat conductivity 0.4W/m.K.

2), natural gas is allowed to rise to well head by insulated tubing by existing method.

3), between well site to the gas gathering station in 1 meter of well site of distance, on buried gathering line, the 1st oil nozzle is set by existing method, then is respectively provided with the 2nd, the 3rd, the 4th oil nozzle with 1300m spacing on this pipeline.

4), first pass through gas well outlet line to add in natural gas and press down ice agent liquid, allow the most again carry and press down the natural gas of ice agent liquid and first pass through the 1st oil nozzle reducing pressure by regulating flow about 9MPa on buried gathering line, natural gas temperature after reducing pressure by regulating flow is allowed to be maintained at 0～9 DEG C, so as to heat absorption heats up from the earth soil layer；Allow the most again carry and press down the natural gas of ice agent liquid by the 2nd, the 3rd oil nozzle reducing pressure by regulating flow 1.5MPa respectively on buried gathering line, allow natural gas temperature after reducing pressure by regulating flow be maintained at 0～9 DEG C, so as to heat absorption heats up from the earth soil layer；Then allow and carry the natural gas pressing down ice agent liquid by last 1 oil nozzle reducing pressure by regulating flow on buried gathering line to 4MPa.Described press down described in " natural gas exploiting method of a kind of cleaning " file that ice agent liquid is number of patent application 2009101436712 any selectable press down ice agent liquid.

5), by reducing pressure by regulating flow to 4MPa natural gas it is delivered to this gas gathering station, and crosses compressor entrance subsequent treatment operation by bypass line in this gas gathering station.

Calculated from knowledge known in this field: gas production 1000m³/ day, well head pressure 22MPa, bottom hole temperature (BHT) 110 DEG C the Su Lige gas stringer application present invention time, natural gas rises to the temperature about 40 DEG C of well head, 20MPa；By these 40 DEG C, in well site, disposable reducing pressure by regulating flow to the temperature of 4MPa is-16 DEG C to 20MPa natural gas.

Calculated further from knowledge known in this field: by these 40 DEG C, 20MPa natural gas be 1.5 DEG C entering the oil nozzle reducing pressure by regulating flow for the first time that arranged by this pipeline at buried gathering line 1 meter to the temperature of 9MPa；When allowing 9MPa, the natural gas of 1.5 DEG C carry 1300 meters in this pipeline, it heat absorption can be warming up to 5.5 DEG C from buried soil layer, and the temperature of the oil nozzle second time reducing pressure by regulating flow arranged by this pipeline by the natural gas of this 9MPa, 5.5 DEG C to 7.5MPa is 0.5 DEG C；When allowing 7.5MPa, the natural gas of 0.5 DEG C carry 1300 meters in this buried pipeline, it heat absorption can be warming up to 4.5 DEG C from buried soil layer, and the temperature of the oil nozzle third time reducing pressure by regulating flow arranged by this pipeline by the natural gas of this 7.5MPa, 4.5 DEG C to 6.5MPa is 1 DEG C；When allowing 6.5MPa, the natural gas of 1 DEG C carry 1300 meters in this pipeline, it heat absorption can be warming up to 5 DEG C from buried soil layer, is-3.75 DEG C by the temperature that the natural gas of this 6.5MPa, 5 DEG C is depressurized to 4MPa by the 4th throttling of oil nozzle that this pipeline is arranged.

Laboratory test shows: the freezing point of Soviet Union's water produced sample of 36-13 well is-2 DEG C；50ml is pressed down ice agent liquid add 50ml Soviet Union the water produced sample of 36-13 well in freezing point be-16 DEG C；5ml is pressed down ice agent liquid add 95ml Soviet Union the water produced sample of 36-13 well in freezing point be-4 DEG C；10ml is pressed down ice agent liquid add 90ml Soviet Union the water produced sample of 36-13 well in freezing point be-6.5 DEG C.

It can thus be appreciated that, wellhead temperature 40 DEG C, the well head pressure 20MPa natural gas temperature when one time, well site reducing pressure by regulating flow is to 4MPa is-16 DEG C, although the minimum operating temperature that still above natural gas line is allowed, it is that natural gas production is allowed, but in order to prevent these-16 DEG C, 4MPa natural gas freeze in pipeline between well site to gas gathering station, generate hydrate, need to add 50% concentration in this natural gas presses down ice agent liquid；And wellhead temperature 40 DEG C, minimum temperature after well head pressure 20MPa natural gas is depressurized to 4MPa by four throttlings of buried not hot insulated line between 3900 meters of well site to gas gathering stations are-3.75 DEG C, in order to prevent natural gas from generating hydrate and ice at such a temperature, need to add 5% concentration in this natural gas presses down ice agent liquid.

Therefore, after technical scheme of the present invention applied by this well, it is possible to effectively utilize big geothermal energy, antifreezing agent consumption natural gas reducing pressure by regulating flow needed for is greatly reduced, there is significant economic benefit.

Open source information shows: low temperature can freeze less than 0 DEG C, and after frost in the soil, heat conductivity drastically declines.

From knowledge known in this field: the buried gathering line buried depth between well site to gas gathering station is all freezing below layer, annual low temperature, at about 9 DEG C, can absorb heat from the earth when the natural gas temperature in pipeline is less than the buried temperature of pipeline and heat up；The thermal capacitance of the earth is unlimited；Natural gas is big ground soil thermal conductivity from the restricted pipeline of heat that the earth absorbs, and outside pipeline, during big ground frost in the soil, heat conductivity can drastically decline；Existing reducing pressure by regulating flow method can arbitrarily reduce natural pressure force value, can the natural gas temperature that carry antifreezing agent be controlled in 0～9 DEG C by the method for reducing pressure by regulating flow.

Embodiment 24

Repeating embodiment 20, embodiment 22, embodiment 23, it the difference is that only:

Step 3) in, in order to utilize big geothermal energy to reduce the antifreezing agent consumption that natural gas dependence own temperature is required when well site reducing pressure by regulating flow, big geothermal energy is utilized to reduce antifreezing agent consumption: pit shaft, well head, well site surface line (or pipe fitting) any position or any more than 2 positions can also be first passed through and add antifreezing agent in natural gas (or natural gas flow)；The natural gas carrying antifreezing agent is allowed to rely on own temperature at well site reducing pressure by regulating flow the most again；The natural gas after the reducing pressure by regulating flow of well site is allowed to rely on own temperature and underground heat repeatedly reducing pressure by regulating flow in buried gathering line between well site to gas gathering station the most again, in order to allow natural gas pass through buried gathering line and heat up from the earth heat absorption.

Described well site reducing pressure by regulating flow meets natural gas production requirement and regulation, the natural gas temperature after reducing pressure by regulating flow can be allowed higher than 0 DEG C and less than the buried mean annual cost of gathering line between well site to gas gathering station or less than 10 DEG C.As those of ordinary skill in the art, can determine the concrete scheme of described well site reducing pressure by regulating flow, throttling number of times (progression), throttle style, restricting element, Restriction Parameters, maximum reducing pressure by regulating flow pressure and temperature, minimum reducing pressure by regulating flow pressure and temperature, optimal reducing pressure by regulating flow pressure and temperature by existing method.

Embodiment 25

Repeating embodiment 1 to embodiment 22, it the difference is that only:

Step 4) in, in order to the natural gas after preventing reducing pressure by regulating flow forms hydrate, ice between well site to gas gathering station in gathering line: first pass through addition antifreezing agent in pit shaft, well head, well site surface line (or pipe fitting), buried gathering line (or pipe fitting) any position or any more than 2 positions natural gas after reducing pressure by regulating flow, the most again the natural gas after reducing pressure by regulating flow is delivered to gas gathering station.

Described antifreezing agent meets natural gas production requirement and regulation, can ensure that natural gas cannot form hydrate, ice between well site to gas gathering station in pipeline；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

From knowledge known in this field: between domestic gas well well site to gas gathering station gathering line have buried have ground lay, the buried gathering line of major part is not incubated (gas field of such as pacifying the border region, the gas wells such as 11 blocks of reviving), and its buried temperature is often below gas hydrates and generates critical temperature；Pacify the border region gas field, Soviet Union's Sulige gas field etc. is positioned in desert, and its buried pipeline is often exposed to earth's surface because of sand dune movement, and the natural gas temperature in pipeline sometimes can be allowed less than 0 DEG C；Soviet Union Sulige gas field, the gas field gas gathering station that the pacifies the border region natural gas temperature that enters the station is a kind of common phenomenon less than 0 DEG C.

As a example by the Soviet Union 11-48-59 well application present invention.

The operational data of Soviet Union's Sulige gas field shows: this well belongs to Soviet Union's Sulige gas field and revives No. 2 existing producing wells of gas gathering station of 11 block.

This well uses summer, two kinds of production technologies of winter, its winter production technique can be summarized as: special throttling arrangement (such as the subsurface choke) reducing pressure by regulating flow arranged in first passing through down-hole oil tube from the natural gas of gas-bearing formation is to 0.5～0.7MPa, continue to rise to well head by oil pipe the most again, it is delivered to gas gathering station the most again by buried gathering line between well head, well site surface gathering and transferring pipeline, well site to gas gathering station, to 3～5MPa subsequently into increase pressure in the compressor that gas gathering station is arranged, then enter back into the defeated operation of subsequent set and transport to outward purification plant.Compressor horsepower is 500 kilowatts, drives with combustion gas.

This well production in summer technique can be summarized as: is spaced 1 and adds methanol in gas well oil pipe, special throttling arrangement (such as the subsurface choke) reducing pressure by regulating flow arranged in first passing through down-hole oil tube from the natural gas of gas-bearing formation is to about 4MPa, carry methanol by oil pipe the most again to continue to rise to well head, it is delivered to gas gathering station by buried gathering line between well head, well site surface gathering and transferring pipeline, well site to gas gathering station the most again, crosses gas gathering station inner compressor and enter the defeated operation of subsequent set and transport to outward purification plant.

The variety of problems that methanol, winter production gas gathering station compressor boost and downhole choke bring is added in order to solve this well production in summer, reduce gas well management workload, guarantee that gas well normally produces, this well applies the present invention to carry out pilot production in November, 2010～in February, 2011, and its technical scheme is:

1), first by the method for underground work, the subsurface choke arranged in existing external diameter 89mm oil pipe in Soviet Union's 11-48-59 well shaft sleeve pipe and this oil pipe is taken out；Described insulated tubing external diameter 99mm, makes with internal diameter 76mm, external diameter 89mm oil pipe and existing method, and inwall does not has undercoating, outer wall to have the glass fibre reinforced plastic insulation layer of thickness 5mm, heat conductivity 0.4W/m.K.

2), by the method for underground work, insulated tubing is put in 7 inches of sleeve pipes of this well shaft again, then allow this well shaft bottom natural gas rise to well head by insulated tubing by existing method.

3) natural gas, is then allowed to rely on own temperature by the 2.2mm oil nozzle reducing pressure by regulating flow of well site surface valve group setting to 4MPa.

4), then first pass through addition antifreezing agent in well site surface line 4MPa natural gas after reducing pressure by regulating flow, the most again this natural gas is delivered to gas gathering station.

This well is applied after technical scheme opening well and making production of the present invention, actually detected shows: this well is with being arranged at the 2.2m oil nozzle in well site according to daily output tolerance 14400m³When controlling/day to produce, casing pressure 18MPa, oil pressure 15MPa, aquifer yield 0.7 ton per day, it is-22～in the winter low temperature environment of about-28 DEG C at nighttime temperature, it is 64～66 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet, and any clogging does not the most occur in the pipeline pipe fitting on oil pipe top, well head (christmas tree)；Being 30～31 DEG C by the temperature of this well 64～66 DEG C, pressure 15MPa natural gas 2.2m oil nozzle reducing pressure by regulating flow to 4MPa by being arranged at well site surface valve group, the most there is not any clogging in throttling oil nozzle, pipe fitting；When by 30～31 DEG C, the natural gas of 4MPa by Soviet Union's 11-48-59 well to No. 2 gas gathering stations between buried not hot insulated line be delivered to No. 2 gas gathering stations time interior when 2～3 are little in this pipeline, generate hydrate and block pipeline, need the disposable 300L that adds in this pipeline to press down ice agent liquid or 600L methanol could de-plugging；When to these 30～31 DEG C, the natural gas of 4MPa adds and presses down ice agent liquid and after addition reaches 80L/ day, it is 8～9 DEG C that this natural gas is delivered to the temperature of No. 2 gas gathering stations by buried not hot insulated line between Soviet Union's 11-48-59 well to No. 2 gas gathering stations, pressure is 3.7MPa, and this pipeline will not be made any clogging occur.

Calculated from knowledge known in this field: Soviet Union's Sulige gas field gas hydrates critical generation temperature about 19 DEG C of pressure 15MPa；Soviet Union's Sulige gas field gas hydrates critical generation temperature about 10.7 DEG C of pressure 4MPa；Soviet Union's Sulige gas field gas hydrates critical generation temperature about 10 DEG C of pressure 3.7MPa；Therefore 3.7MPa, the natural gas of 8～9 DEG C necessarily generate hydrate between this well well site to No. 2 gas gathering stations in buried pipeline.

Laboratory test shows: Soviet Union's water produced freezing point of 11-48-59 well be-2 DEG C, 10ml presses down ice agent liquid and adds 90ml and revive in the water produced sample of 11-48-59 well, and the freezing point of this water sample is-6.5 DEG C；Therefore, press down ice agent liquid and can effectively reduce this well water sample freezing point.

This mill trial results shows: after this well uses technical scheme of the present invention, without downhole choke oil nozzle, gas gathering station compressor and methanol (or other antifreezing agents) are able to ensure that the annual normal production of this well equally, it is able to ensure that this well natural gas relies on own temperature reducing pressure by regulating flow to producing desirable pressure in well site, in natural gas add press down ice agent liquid 80L/ day after utilize existing be not incubated buried gathering line can be by natural gas smooth delivery of power to No. 2 gas gathering station, and natural gas can be made after entering gas gathering station, to cross compressor and be directly entered gas gathering station subsequent treatment operation and meet outer defeated requirement；Thus efficiently solved this well production in summer since building up and use methanol, winter production use gas gathering station compressor boost and use the defects such as the subsurface choke reducing pressure by regulating flow produced pollution, power consumption in oil pipe.During test, this well is accumulative saves methanol 2.3 side, produces methanol poison sewage 7 side less many, also saves big capacity compressor natural gas, and economic benefit and environmental benefit are the most notable.

Embodiment 26

Repeating embodiment 1 to embodiment 24, it the difference is that only:

Step 4) in, in order to the natural gas after preventing reducing pressure by regulating flow generates hydrate between well site to gas gathering station in gathering line: with hot insulated line, the natural gas after reducing pressure by regulating flow can also be delivered to gas gathering station.

Described hot insulated line can ensure that natural gas cannot generate hydrate, ice in this pipeline, meets gas well liquid loading requirement and regulation；As those of ordinary skill in the art, can determine the concrete thermal retardation form of described hot insulated line, type, structure, physical dimension, material, service life by existing method, make technique, it is possible to determine the heat conductivity of described hot insulated line heat-insulation layer, maximum gauge, minimum thickness, using method, service life

Su10 Block uses well site to add thermal throttle production technology: natural gas rises to the well head being incubated by hotwater tracing by oil pipe, it is heated to about 70 DEG C subsequently into the heating furnace being arranged at well site, subsequently into utilizing the disposable reducing pressure by regulating flow of Special oil nozzle to about 4MPa in the surface gathering and transferring valve group of well site, then the buried gathering line by being incubated with yellow jacket polyurethane foam insulation layer is delivered to gas gathering station.

This well is applied after technical scheme opening well and making production of the present invention, actually detected shows: this well is with being arranged at the Special oil nozzle of well site surface valve group according to daily output tolerance 24000m³When controlling/day to produce, casing pressure 20MPa, oil pressure 19.4MPa, it is-24～in the winter low temperature environment of-27 DEG C at nighttime temperature, stopping adding methanol, stoppage in transit wellsite heater, stopping in well mouth oil pipe with wellsite heater hot water to well head (christmas tree) tracing thermal-insulating, it is 69～71 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet；After allowing this well institute producing natural gas cross heating furnace by bypass line, direct temperature after well site reducing pressure by regulating flow to 4MPa, its reducing pressure by regulating flow is 24～26 DEG C, and it is 19～21 DEG C that natural gas enters the temperature of gas gathering station；During test, the most there is not clogging in this well all pipeline pipe fittings between oil pipe top to gas gathering station.

This mill trial results shows: after this well uses technical scheme of the present invention, it is able to ensure that natural gas relies on own temperature pressure required for well site reducing pressure by regulating flow to production, buried pipeline between well site to the gas gathering station of existing yellow jacket polyurethane foam plastics heat-insulation layer insulation can be utilized by natural gas smooth delivery of power to gas gathering station, to efficiently solve this well and relied on the heating of methanol, wellsite heater and hotwater tracing to be incubated the difficult problem maintaining production since building up production always；During test, this well is accumulative saves about methanol 4 side, produce methanol poison sewage 52 side less, save ten thousand stere on heating furnace natural gas, save a large amount of dosing expense and heating furnace operation and maintenance cost, also can save the fixed investment expense of lower 1 heating furnace, economic benefit and environmental benefit are the most notable.

Embodiment 27

Repeating embodiment 26, it the difference is that only:

Further, first by existing method, the gathering line that is not incubated between well site to gas gathering station is incubated, then with insulation rear line, the natural gas after reducing pressure by regulating flow is delivered to gas gathering station.

Natural gas after described insulation can ensure that reducing pressure by regulating flow cannot generate hydrate, ice in described insulation rear line, meets gas well liquid loading requirement and regulation；As those of ordinary skill in the art, the concrete scheme of described insulation, method is can determine by existing method, can determine the concrete thermal retardation form of described insulation rear line, type, structure, physical dimension, material, service life, make technique, it is possible to determine the heat conductivity of described insulation rear line heat-insulation layer, maximum gauge, minimum thickness, using method, service life.

As a example by the Soviet Union 11-48-59 well application present invention.

Add, in order to solve this well, the variety of problems that methanol brings, reduce gas well management workload degree, it is ensured that gas well normally produces, and this well applies the present invention to carry out pilot production in November, 2010～in February, 2011, and its technical scheme is:

Calculated from knowledge known in this field: Soviet Union's Sulige gas field gas hydrates critical generation temperature about 10.7 DEG C of pressure 4MPa；Soviet Union's Sulige gas field gas hydrates critical generation temperature about 10 DEG C of pressure 3.7MPa；Therefore 3.7MPa, the natural gas of 8～9 DEG C necessarily generate hydrate between this well well site to No. 2 gas gathering stations in buried pipeline.

Therefore, after the Soviet Union 11-48-59 well application present invention, although hydrate will not be generated at pit shaft, well head, it is possible to rely on own temperature at well site reducing pressure by regulating flow to producing desirable pressure, but between the gas gathering station of well site to No. 2, hydrate can in buried not hot insulated line, be generated.

Calculated from knowledge known in this field: by the temperature about 20～22 DEG C when the 11-48-59 well site reducing pressure by regulating flow natural gas buried heat insulation pipe line of 4000 cream colour jacket polyurethane foam plastics heat-insulation layer insulations to 30～31 DEG C, 4MPa of reviving is delivered to No. 2 gas gathering stations, generate critical temperature far above the hydrate of this well 4MPa natural gas.

Therefore, in order to prevent from reviving, 11-48-59 well natural gas after the reducing pressure by regulating flow of well site buried insulation in gathering line between well site to gas gathering station generates hydrate, Soviet Union's 11-48-59 well can also apply the present invention further, its concrete technical scheme is: first by existing method, gathering line between this well well site to No. 2 gas gathering stations is carried out yellow jacket polyurethane foam plastics heat-insulation layer isothermal holding, with the pipeline after this insulation, this well natural gas is delivered to No. 2 gas gathering stations the most again.

Soviet Union's 11-48-59 well applies the production detection of technical scheme of the present invention to show: in order to prevent this well natural gas after the reducing pressure by regulating flow of well site buried insulation in gathering line between well site to gas gathering station from generating hydrate, to add and to press down ice agent liquid 80L/ day every day in natural gas；Calculating shows, needs to press down ice agent total amount of liquid and adds up 292 tons, press down the calculating of 10000 yuan/ton, ice agent liquid market price according to this in 10 years after this well application technical scheme of the present invention, and the total cost of needs is 2,920,000 yuan；Calculate further and understand, pipeline insulation belongs to disposable input, effective application life of yellow jacket polyurethane foam plastics heat-insulation layer is up to more than ten years, carry out the total cost of insulation transformation less than 1,000,000 yuan with the gathering line that is not incubated buried between yellow jacket polyurethane foam plastics heat-insulation layer 4000 meters of well site to gas gathering stations existing to this well, used by this well 10 years, press down the 35% of ice agent liquid expense.

Therefore, technical scheme of the present invention applied further by Soviet Union's 11-48-59 well, it is possible to produce bigger economic benefit, it is possible to natural gas production cost and expense are greatly reduced.

Embodiment 28

Repeating embodiment 1 to embodiment 22, embodiment 25, it the difference is that only:

Further, step 4) in, in order to the natural gas after reducing antifreezing agent consumption and preventing reducing pressure by regulating flow generates hydrate between well site to gas gathering station in gathering line: first allow the natural gas after reducing pressure by regulating flow enter in the gas-liquid separator being arranged at well site, by gas-liquid separator, natural gas is separated with liquid, and by existing method, isolated liquid is carried out subsequent treatment；In isolated natural gas, add antifreezing agent the most again, then the natural gas carrying antifreezing agent is delivered to gas gathering station.

Described gas-liquid separator can be 1 or more than 2, and more than 2 gas-liquid separators can be in parallel or/and connect.

The liquid of more than 50% in natural gas can be separated from natural gas by described gas-liquid separator, can meet natural gas production requirement and regulation；As those of ordinary skill in the art, can determine the particular type specification of described gas-liquid separator, method for making, installation method, using method by existing method, at most quantity is set, minimum quantity is set, it is possible to determine more than 2 gas-liquid separation implement body installation methods in parallel or series, usings method.

As a example by the Soviet Union 11-48-59 well application present invention.

In order to press down ice agent volume when the existing buried gathering line of the gas utilization after reducing this well reducing pressure by regulating flow is delivered to No. 2 gas gathering stations, this well has carried out antifreezing agent fall amount pilot production in December, the 2010 application present invention, its concrete technical scheme is: arrange 1 gas-liquid separator in well site, first allow the natural gas after reducing pressure by regulating flow enter gas-liquid separator is isolated free water (aqueous water), and isolated free water is transported process further；Then add in isolated natural gas and press down ice agent liquid, then allow carry to press down in the natural gas of ice agent liquid enters the buried gathering line of existing well site to gas gathering station and be delivered to No. 2 gas gathering stations.Described gas-liquid separator is commodity, maximum outside diameter 1200mm, and height is 2000mm, is incubated with 8mm thickness polyurethane foam plastics heat-insulation layer.

Further pilot production detection after technical scheme of the present invention applied by this well shows: the natural gas after reducing pressure by regulating flow enters gas-liquid separator can divide water 0.5 ton per day, add in this natural gas again and this natural gas can be allowed to pass through the buried gathering line of existing well site to gas gathering station after pressing down ice agent liquid 25L/ day to be delivered to No. 2 gas gathering stations, and this gas gathering station inner compressor can be crossed be directly entered subsequent treatment operation and transport to outward purification plant.

This mill trial results shows: after this well uses technical scheme of the present invention, gas-liquid separator can isolate free water and light oil mixture 0.6 ton per day, aqueous water 0.5 ton per day every day, it is possible to save antifreezing agent more than 68%；Economic benefit and environmental benefit are the most notable.

Embodiment 29

Repeating embodiment 26, embodiment 28, it the difference is that only:

First allow the natural gas after reducing pressure by regulating flow enter in the gas-liquid separator that well site is arranged, by gas-liquid separator, natural gas is separated with liquid, and by existing method, isolated liquid is carried out subsequent treatment；Then isolated natural gas hot insulated line is delivered to gas gathering station.

Described hot insulated line can ensure that natural gas cannot generate hydrate, ice in this pipeline, meets gas well liquid loading requirement and regulation；As those of ordinary skill in the art, can determine the concrete thermal retardation form of described hot insulated line, type, structure, physical dimension, material, using method, service life by existing method, make technique, it is possible to determine the heat conductivity of described hot insulated line heat-insulation layer, maximum gauge, minimum thickness, using method, service life.

Embodiment 30

Repeating embodiment 27, embodiment 28, it the difference is that only:

First allow the natural gas after reducing pressure by regulating flow enter in the gas-liquid separator that well site is arranged, by gas-liquid separator, natural gas is separated with liquid, and by existing method, isolated liquid is carried out subsequent treatment；Then the isolated natural gas existing gathering line carrying out being incubated is delivered to gas gathering station.

The described existing gathering line carrying out being incubated can ensure that natural gas cannot generate hydrate, ice in this pipeline, meets gas well liquid loading requirement and regulation；As those of ordinary skill in the art, by existing method can determine described in carry out being incubated the concrete thermal retardation form of existing gathering line, type, structure, physical dimension, material, service life, make technique, it is possible to the heat conductivity of existing gathering line heat-insulation layer that carries out described in determining being incubated, maximum gauge, minimum thickness, using method, service life

Embodiment 31

Repeating embodiment 28 to embodiment 30, it the difference is that only:

Described insulation, solar energy tracing thermal-insulating meet natural gas production requirement and regulation, can allow isolated liquid will not in gas-liquid separator and liquid outlet freeze；As those of ordinary skill in the art, can determine insulation, the specific category of solar energy tracing thermal-insulating, mode, effective using method, concrete insulation material, concrete insulation layer thickness, concrete thermal-insulating scheme by existing method.

Open source information shows: Soviet Union's Sulige gas field, gas field of pacifying the border region belong to sunshine strongly, the desert area that landform is open；Existing solar water heater can provide 80 DEG C of hot water, it is possible to for tracing thermal-insulating.

Embodiment 32

Repeating embodiment 28 to embodiment 30, it the difference is that only:

In order to prevent the liquid separated from natural gas in gas-liquid separator and liquid outlet freezes, generates hydrate: can also be by the buried or buried insulation of existing method of described gas-liquid separator.

Open source information shows: average annual 9～10 DEG C of the following ground temperature of layer is frozen in Soviet Union's Sulige gas field, gas field etc. of pacifying the border region.

Embodiment 33

A kind of natural gas production method, comprises the steps:

2), natural gas is allowed to rise to well head by insulated tubing.

3), with hot insulated line, natural gas is delivered to gas gathering station.

Described reducing pressure by regulating flow refers to the reducing pressure by regulating flow of optional position, operation in gas gathering station；Described reducing pressure by regulating flow refers to the reducing pressure by regulating flow utilizing private section fluid element (such as oil nozzle) to complete；Described reducing pressure by regulating flow is one-level reducing pressure by regulating flow.

Described insulated tubing can allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate or/and temperature after natural gas can be allowed to rely on own temperature, pressure and hot insulated line to be delivered to gas gathering station reducing pressure by regulating flow is not less than minimum operating temperature that natural gas line pipe fitting allowed or is not less than-20 DEG C, can put in Wellbore of Gas Wells sleeve pipe or in oil pipe by existing method, meet gas well liquid loading requirement and regulation；As those of ordinary skill in the art, the particular type of described insulated tubing is can determine by existing method, structure, physical dimension, material, service life, make technique, can determine the particular type of described insulated tubing outer wall (or outside) heat-insulation layer, structure, physical dimension, material, maximum gauge, minimum thickness, heat conductivity, make technique, can determine that described insulated tubing is incubated, adiabatic, the concrete form of heat insulation structural, type, physical dimension, material, heat conductivity, make technique, can determine that the particular number in Wellbore of Gas Wells sleeve pipe or in oil pipe put into by described insulated tubing, length (or degree of depth), position.

Described hot insulated line can be greatly reduced natural gas heat loss between well site to gas gathering station in gathering line, can ensure that natural gas rely on own temperature, pressure to be delivered to gas gathering station reducing pressure by regulating flow after temperature be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C；As those of ordinary skill in the art, can determine the concrete thermal retardation form of described hot insulated line, type, structure, physical dimension, material, using method, service life by existing method, make technique, it is possible to determine the heat conductivity of described hot insulated line heat-insulation layer, maximum gauge, minimum thickness, using method, service life.

Described reducing pressure by regulating flow can reduce natural gas energy consumption and cost, production requirement and the regulation of gas gathering station can be met, natural gas processing purification plant can be met production requirement and the regulation, beneficially natural gas processing purification plant of the natural gas from gas gathering station are reduced energy consumption and cost；As those of ordinary skill in the art, the concrete scheme of described reducing pressure by regulating flow, mode, Restriction Parameters, restricting element is can determine, it is possible to determine natural gas maximum temperature after described gas gathering station reducing pressure by regulating flow, minimum temperature, optimum temperature, maximum pressure, minimum pressure, optimum pressure by existing method.

From knowledge known in this field: when natural gas collecting station reducing pressure by regulating flow, generally reducing pressure by regulating flow in heating furnace or/and on furnace outlet pipeline, reducing pressure by regulating flow on the pipeline before entering separator also having；Generally with the private section fluid element reducing pressure by regulating flow such as Special oil nozzle, needle valve, special choke valve, have also can effectively reduce the reducing pressure by regulating flow such as pipe fitting such as reducer pipe, orifice plate, gate valve of gas pressure with other；Commonly used once (one-level) throttling in heating furnace, the method that secondary (two grades) throttles on furnace outlet pipeline, have is also adopted by the method that once (one-level) throttles on furnace outlet pipeline；Commonly used one-level throttling, the first order heating furnace of carrying out before first order heating furnace in some gas fields (such as general smooth gas field) carries out two-step throttle, second level heating furnace carry out three grades of throttlings methods after reheating after heating.

From knowledge known in this field: in existing gas gathering station produces, all use heating → reducing pressure by regulating flow method, heating furnace heated natural gas is the most first used before natural gas reducing pressure by regulating flow, if natural gas is the most first heat temperature raising before reducing pressure by regulating flow, natural gas temperature and natural gas line, pipe fitting, equipment running temperature can be made to be down to less than-20 DEG C.

As a example by the Soviet Union 10-50-54 well application present invention.

Soviet Union's 10-50-54 well belongs to Soviet Union's existing producing well of Sulige gas field Su10 Block.

The production technology of this well can be summarized as: after this well natural gas rises to well head by oil pipe, it is introduced in being arranged at the heating furnace in well site and is heated to 65～70 DEG C, the disposable reducing pressure by regulating flow of Special oil nozzle arranged by ground, well site the most again, to about 4MPa, is delivered to gas gathering station with the yellow buried gathering line of jacket polyurethane foam insulation of maximum working pressure (MWP) 6.4MPa, 3200 meters long the most again.

Methanol and the variety of problems brought with wellsite heater hot water is manually added to well head tracing thermal-insulating in order to solve Soviet Union's 10-50-54 well, reduce gas well management workload degree, guarantee that gas well normally produces, this well applies the present invention to carry out pilot production in Decembers, 2008～in February, 2009, and its technical scheme is: first with operational method under existing well by this casing plain tubing take out from sleeve pipe；By operational method under existing well, insulated tubing is put into this casing the most again, allow natural gas rise to well head by insulated tubing；Then allow well head gas utilization bypass line out cross the existing heating furnace being arranged at well site, rely on own temperature by disposable (i.e. one-level) reducing pressure by regulating flow of the existing Special oil nozzle being arranged at ground, well site to 4MPa；It is delivered to gas gathering station the most again with the buried insulation gathering line of existing yellow jacket polyurethane foam insulation layer insulation.Described insulated tubing external diameter 99mm, makes with external diameter 89mm, internal diameter 76mm oil pipe and existing method, does not has undercoating, outer wall to have thickness 5mm, heat conductivity to be 0.4W/m.K glass fibre reinforced plastic insulation layer.

This well is applied after technical scheme opening well and making production of the present invention, actually detected shows: this well is with being arranged at the oil nozzle in well site according to daily output tolerance 24000～25000m³When controlling/day to produce, it is-24～in the winter low temperature environment of about-27 DEG C at nighttime temperature, it is 69～71 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet, oil pressure 19MPa, casing pressure 20MPa, stop adding in well mouth oil pipe methanol stopping wellsite heater hot water to well head (christmas tree) tracing thermal-insulating after, the most there is not clogging in the pipeline pipe fitting on this well oil pipe top, well head (christmas tree) in the experimental period of 80 days.

Calculated from knowledge known in this field: according to the existing 3200 meters of buried gathering lines of this well be Huang jacket polyurethane foam insulation layer be incubated, design the actual measurement year-round average temperature of the buried degree of depth 1.6 meters (freezing 1.5 meters of layer) be 9 DEG C, the defeated distance of collection in well site to gas gathering station be 3200 meters of calculating, temperature when this well wellhead temperature 69～71 DEG C, well head pressure 19MPa natural gas are delivered to gas gathering station from well site is about 60～62 DEG C, pressure about 18MPa；Calculate further and understand, be 17～18 DEG C by the natural gas of temperature 60～62 DEG C, pressure 18MPa in the temperature of gas gathering station reducing pressure by regulating flow to 4MPa, remain above the gas hydrates that pressure is 4MPa and generate critical temperature 10.7 DEG C.

After technical scheme of the present invention applied by this well, natural gas temperature after entering gas gathering station has been up to 60～62 DEG C, temperature after heating with heating furnace before the reducing pressure by regulating flow of well site with this well natural gas is suitable, heating furnace heat temperature raising it has been no longer necessary to, therefore, it is possible to relied on the defects such as power consumption produced by heating furnace heat temperature raising since overcoming this well to build up production in well site always before gas gathering station reducing pressure by regulating flow.

The natural gas of 18MPa it is not enough to carry owing to being incubated buried pipeline pressure rating between this well well site to gas gathering station. rely on the defect such as power consumption of reducing pressure by regulating flow after wellsite heater heating to solve this well, this well can also be by the below scheme application present invention, and its concrete technical scheme is:

1), by the method for underground work, existing external diameter 89mm oil pipe in Soviet Union's 10-50-54 well shaft sleeve pipe is taken out.

2), by the method for underground work, insulated tubing is put in this well shaft sleeve pipe；Described insulated tubing external diameter 99mm, makes with internal diameter 76mm, external diameter 89mm oil pipe and existing method, and inwall does not has undercoating, outer wall to have the glass fibre reinforced plastic insulation layer of thickness 5mm, heat conductivity 0.4W/m.K.

3), buried heat insulation pipe line between this well to gas gathering station is replaced by the insulation buried pipeline of pressure grade 20MPa.

4), this well shaft bottom natural gas is allowed to rise to well head by insulated tubing by existing method.

5), natural gas is delivered to gas gathering station by the insulation buried pipeline of pressure grade 20MPa.

6), natural gas is allowed to cross the heating furnace reducing pressure by regulating flow arranged in gas gathering station to 4MPa by bypass, subsequently into gas gathering station subsequent treatment operation.

Embodiment 34

Repeating embodiment 33, it the difference is that only:

Described reducing pressure by regulating flow refers to the reducing pressure by regulating flow in equipment (in heating furnace)；Described reducing pressure by regulating flow refers to utilize and can effectively reduce the reducing pressure by regulating flow that the pipe fitting (such as needle valve) of gas pressure completes；Described reducing pressure by regulating flow is more than 2 grades reducing pressure by regulating flows.

Embodiment 35

Repeating embodiment 33, it the difference is that only:

Described reducing pressure by regulating flow refers to the reducing pressure by regulating flow in gas gathering station on any pipeline, pipe fitting.

Embodiment 36

Repeating embodiment 33 to 35, it the difference is that only:

Step 3) in, in order to prevent temperature when well head natural gas out is delivered to gas gathering station by existing not hot insulated line the lowest: first by existing method, buried between well site to gas gathering station or surface gathering and transferring pipeline are incubated, with insulation rear line, natural gas is delivered to gas gathering station the most again.

Described insulation, insulation rear line can be greatly reduced natural gas heat loss between well site to gas gathering station in gathering line, can ensure that natural gas rely on own temperature, pressure to be delivered to gas gathering station reducing pressure by regulating flow after temperature be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C；As those of ordinary skill in the art, the concrete scheme of described insulation, method is can determine by existing method, can determine the concrete thermal retardation form of described insulation rear line, type, structure, physical dimension, material, using method, service life, make technique, it is possible to determine the heat conductivity of described insulation rear line heat-insulation layer, maximum gauge, minimum thickness, using method, service life.

Calculated from knowledge known in this field: be the maturation method commonly used during oil gas field produces to be not incubated buried or surface gathering and transferring pipeline between well site to gas gathering station carrying out yellow jacket polyurethane foam plastics heat-insulation layer insulation.

As a example by the G48-4A well application present invention.

The operational data in gas field of pacifying the border region shows: this well belongs to the existing producing well of south 21, gas field gas gathering stations administration of pacifying the border region, well depth about 3500 meters, shaft bottom natural gas temperature about 110 DEG C, bottom pressure about 20MPa；This well uses external diameter 89mm, the plain tubing of internal diameter 76mm produces, without special downhole choke device in oil pipe, with being arranged at the Special oil nozzle reducing pressure by regulating flow of gas gathering station, adjusting gas production；Not being incubated buried collector and delivery pipe line length 7000 meters between well site to gas gathering station, bury underground 1.6 meters (freezing 1.5 meters of layer), average annual 9 DEG C of buried ground temperature, minimum ground temperature is less than 5 DEG C；This well uses the method guarantee production adding methanol with high-pressure pump continuously in pit shaft oil pipe (or sleeve pipe), during winter production, this well adds methanol 400L/ day average every day in well mouth oil pipe (or sleeve pipe), and during production in summer, this well adds 200～300L/ days of methanol average every day in well mouth oil pipe (or sleeve pipe)；On July 8th, 2008, survey this well casing pressure 16MPa, oil pressure 15.4MPa, produce tolerance 20000m daily³/ day, produce water 1 ton per day, wellhead temperature 13.2 DEG C daily；On December 19th, 2008, surveys this well casing pressure 16MPa, oil pressure 14.2MPa, produces tolerance 20000m daily³/ day, produce water 0.6 ton per day, wellhead temperature 8 DEG C daily.

The production technology of this well can be summarized as: first add methanol continuously in pit shaft (oil pipe or sleeve pipe) or in surface line with high-pressure pump, allow natural gas carry methanol and be delivered to southern 21 gas gathering stations by not hot insulated line buried between well site to gas gathering station, be then depressurized to about 4MPa with throttling after the heating furnace heat temperature raising of setting in southern 21 gas gathering stations.

Calculated further from knowledge known in this field: average annual 9 DEG C of the buried buried ground temperature of not hot insulated line between this well well site to gas gathering station, it wellhead temperature when production in summer is 13.2 DEG C, during winter production, temperature is 8 DEG C, therefore the temperature that this well natural gas enters southern 21 gas gathering stations summer is inevitably less than 13 DEG C, and the temperature entering this station winter is inevitably less than 9 DEG C；The natural gas of pressure 15.4MPa, temperature 13 DEG C is heated without heating furnace in southern 21 gas gathering stations, directly reducing pressure by regulating flow is-28 DEG C to the temperature of 4MPa, the natural gas of pressure 14.2MPa, temperature 9 DEG C is heated without heating furnace in southern 21 gas gathering stations, directly reducing pressure by regulating flow is-29 DEG C to the temperature of 4MPa, the running temperature the most allowed well below natural gas line；Therefore, if this summer in well winter enter southern 21 gas gathering stations natural gas not at this station heat temperature raising with regard to direct reducing pressure by regulating flow to 4MPa, by making this station natural gas line pipe fitting running temperature far below its minimum operating temperature allowed, it is that natural gas produces not permitted in system, technique.

Add methanol in well site to solve this well, heat the problems such as the environmental protection, the power consumption that bring at gas gathering station heating furnace, it is ensured that gas well normally produces, and this well applies the present invention to carry out pilot production in January, 2009～April, and its technical scheme is:

1), first with the method for underground work the insulated tubing of external diameter 58mm put into G48-4A well shaft the oil pipe that internal diameter is 76mm in；Described insulated tubing external diameter 58mm, makes with external diameter 48mm, the oil pipe of internal diameter 34mm and existing method, and inwall does not has undercoating, outer wall to have the glass fibre reinforced plastic insulation layer of thickness 5mm, heat conductivity 0.4W/m.K.

2), natural gas is allowed to rise to well head by insulated tubing by existing method the most again.

3), allow oil nozzle reducing pressure by regulating flow that natural gas arranged by well site to 4MPa.

4), ice agent liquid or methanol are pressed down by surface line natural gas after reducing pressure by regulating flow in well site adds, then allow carry and press down the natural gas of ice agent liquid or methanol and be delivered to southern 21 gas gathering stations by the existing buried gathering line that is not incubated, and in gas gathering station, enter subsequent treatment operation by more the miss the stop heating furnace of interior setting of bypass line further.

From knowledge known in this field: uniformly wrap up 5mm heavy sheet glass steel heat-insulation layer by existing method at the oil-pipe external wall of external diameter 48mm, internal diameter 34mm and just can make the insulated tubing that external diameter is 58mm, its external diameter now uses pipe aperture 18mm less than G48-4A well, can the annular space that with oil pipe form width 9mm existing with this well；Underground work is the mature technology that natural gas produces, with the method can external diameter 58mm oil pipe insulated tubing put into G48-4A well shaft the oil pipe that internal diameter is 76mm in, and the annular space of formed width 9mm.

Calculated from knowledge known in this field: when this well applies technical scheme of the present invention to produce, per diem gas production 20000m³/ day counts, natural gas is risen to the temperature of well head and can reach more than 65 DEG C from this shaft bottom by insulated tubing, exceed the actual measurement wellhead temperature more than 51 DEG C when this well plain tubing produces, be significantly larger than this well casing pressure 15.4MPa natural gas hydrate generate critical temperature, it is impossible on oil pipe top, well head generate hydrate；Calculate further and understand, by 65 DEG C, 15.4MPa natural gas be 29 DEG C in the temperature of well site reducing pressure by regulating flow to 4MPa, the hydrate higher than 4MPa generates critical temperature, and therefore this natural gas of this well can not generate hydrate when at well site reducing pressure by regulating flow.

This well is applied after technical scheme opening well and making production of the present invention, actually detected shows: this well is with being arranged at the Special oil nozzle of well site valve group according to daily output tolerance 20000m³When controlling/day to produce, casing pressure 16MPa, oil pressure 15MPa, be-20～in the winter low temperature environment of about-29 DEG C at nighttime temperature, and it is 72～74 DEG C that natural gas rises to the temperature of well mouth oil pipe outlet；Temperature after well site reducing pressure by regulating flow to 4MPa is 36～38 DEG C；The temperature entering southern 21 gas gathering stations is 9～11 DEG C, pressure 3.5MPa；During testing, when not by surface line natural gas after reducing pressure by regulating flow in well site adds press down ice agent liquid or methanol time, between existing well site to gas gathering station, the buried gathering line that is not incubated is frequently occluded, and needs in well site emptying decompression or disposably addition 300L presses down ice agent liquid or 600L methanol could de-plugging in pipeline from well site；And add 50L in by well site surface line natural gas after reducing pressure by regulating flow when pressing down ice agent liquid or 100L methanol, between existing well site to gas gathering station, the buried gathering line that is not incubated occurs without any clogging.

This mill trial results shows: after this well uses technical scheme of the present invention, and in annual lowest temperature environment, this well is not added with methanol, it is possible to rely on natural gas own temperature reducing pressure by regulating flow to producing desirable pressure in well site, it is possible to ensure that this well produces normal；Really can normally be delivered to gas gathering station by natural gas adding after 50L presses down ice agent liquid or 100L methanol, and in gas gathering station, cross heating furnace entrance subsequent treatment operation；Efficiently solve this well has relied on methanol to maintain production, rely on the pollution of reducing pressure by regulating flow generation, power consumption defect after gas gathering station heating furnace heating since building up production always.During test, this well is accumulative saves methanol 30 in many ways, produces methanol poison sewage 100 in many ways less, saves on heating furnace natural gas incomparably, used by press down ice agent liquid or methanol expense reduces by more than 75%, economic benefit and environmental benefit are the most notable.

From knowledge known in this field: be maturation method conventional during oil gas field produces to be not incubated buried Oil-Gas Gathering Transferring Pipeline between well site to gas gathering station carrying out the insulation of yellow jacket polyurethane foam plastics heat-insulation layer；Buried gathering line commonly used 5mm thickness Huang jacket polyurethane foam plastics heat-insulation layer insulation between Sulige gas field Su10 Block gas well well site to gas gathering station of Soviet Union；Therefore, the gathering line that is not incubated buried between existing for this well 7000 meters of well site to gas gathering stations can be transform as pipeline with the insulation of 5mm thickness Huang jacket polyurethane foam plastics heat-insulation layer by existing method.

Calculated from knowledge known in this field: this well application technical scheme of the present invention is risen to 72～74 DEG C of well head, 15MPa natural gas be delivered to the temperature about 51～53 DEG C of southern 21 gas gathering stations with the buried heat insulation pipe line that 7000 cream-coloured jacket polyurethane foam plastics heat-insulation layers are incubated, pressure about 14MPa, the gas hydrates critical generation temperature far above 14MPa；By 51～53 DEG C, the pressure 14MPa natural gas temperature when southern 21 gas gathering stations rely on the direct reducing pressure by regulating flow of own temperature to 4MPa is 14～16 DEG C, higher than the hydrate of 4MPa natural gas critical generation temperature.

Therefore, during this well application present invention, it is also possible to allow natural gas be delivered to reducing pressure by regulating flow after gas gathering station by hot insulated line, hydrate will not be generated when reducing pressure by regulating flow, it is possible to be directed across gas gathering station internally heated oven and enter subsequent treatment operation.Its concrete technical scheme is as follows:

3), first by existing method the buried gathering line 5mm thickness Huang jacket polyurethane foam plastics heat-insulation layer that is not incubated between G48-4A well well site to southern 21 gas gathering stations is incubated, with this insulation rear line, G48-4A well natural gas is delivered to southern 21 gas gathering stations the most again.

4) natural gas is allowed to cross, by bypass line, the heating furnace entrance subsequent treatment operation that southern 21 gas gathering stations are arranged.

Embodiment 37

Repeating embodiment 33 to 36, it the difference is that only:

Further, step 4) in, in order to prevent natural gas from generating hydrate, ice when gas gathering station reducing pressure by regulating flow and after reducing pressure by regulating flow in gas gathering station pipeline pipe fitting: first pass through gathering line (or pipe fitting) between pit shaft, well head, well site surface line (or pipe fitting), well site to gas gathering station, gas gathering station gut line pipe fitting any position or any more than 2 positions and add antifreezing agent in natural gas, allow natural gas rely on own temperature reducing pressure by regulating flow in gas gathering station the most again.

Described antifreezing agent meets natural gas production requirement and regulation, can ensure that natural gas cannot form hydrate, ice when gas gathering station reducing pressure by regulating flow and after reducing pressure by regulating flow in gas gathering station pipeline pipe fitting；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

Embodiment 38

A kind of natural gas production method, comprises the steps:

2), natural gas is allowed to rise to well head by insulated tubing.

3), in natural gas, antifreezing agent is added.

4) natural gas, is allowed to rely on own temperature to be delivered to gas gathering station by gathering line buried between well site to gas gathering station after well site reducing pressure by regulating flow is cooled to 0.5～9 DEG C, to allow natural gas pass through buried gathering line absorb heat from the earth, prevent natural gas from generating hydrate in gathering line.

5), allow natural gas enter in the gas-liquid separator that gas gathering station is arranged, by gas-liquid separator, natural gas is separated with liquid, and by existing method, isolated liquid is carried out subsequent treatment.

7), allow the natural gas reducing pressure by regulating flow entering natural gas purification processing factory be cooled to more than-8 DEG C, enter back into the defeated operation of subsequent set or link.

Described insulated tubing can allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate or/and natural gas can be allowed to rely on own temperature temperature after well site reducing pressure by regulating flow more than 10% to be not less than 0.5 DEG C；As those of ordinary skill in the art, the particular type of described insulated tubing is can determine by existing method, structure, physical dimension, material, service life, make technique, can determine the particular type of described insulated tubing outer wall (or outside) heat-insulation layer, structure, physical dimension, material, maximum gauge, minimum thickness, heat conductivity, make technique, can determine that described insulated tubing is incubated, adiabatic, the concrete form of heat insulation structural, type, physical dimension, material, heat conductivity, make technique, can determine that the particular number in Wellbore of Gas Wells sleeve pipe or in oil pipe put into by described insulated tubing, length (or degree of depth), position.

Described antifreezing agent meets natural gas production requirement and regulation, can ensure that natural gas relies on own temperature, underground heat and antifreezing agent cannot form hydrate, ice；As those of ordinary skill in the art, the specific category of described antifreezing agent, component, method for making, research on maximum utilized quantity, minimum amount, optimum amount, effective dose is can determine, it is possible to determine the concrete Adding Way of described antifreezing agent, addition equipment, coal addition position, most coal addition position number, minimum coal addition position number by existing method.

Open source information and knowledge known in this field show: gas field of pacifying the border region, Soviet Union's Sulige gas field, the gas gathering station of DaNiuDi gas field are not incubated to purifying pipeline between plant stand, all it is embedded in and freezes below layer (less than 1.6 meters), buried average temperature of the whole year 9 DEG C, length is generally 5000～300000 meters.

Embodiment 39

Repeating embodiment 38, it the difference is that only:

Obviously, the above embodiment of the present invention is only for clearly demonstrating example of the present invention, and is not the restriction to embodiments of the present invention.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here cannot all of embodiment be given exhaustive.Every belong to obvious change that technical scheme extended out or the variation row still in protection scope of the present invention.

Claims

1. a natural gas production method, it is characterised in that comprise the steps:

1) insulated tubing is put in Wellbore of Gas Wells sleeve pipe or in oil pipe；

2) natural gas is allowed to rise to well head by insulated tubing；

Described insulated tubing can allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate, or/and natural gas can be allowed to rely on own temperature temperature after well head or well site reducing pressure by regulating flow to be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C.

Natural gas production method the most according to claim 1, it is characterized in that, described insulated tubing includes that pipe outer wall has any one or two or more compound tube combined of the oil pipe of heat-insulation layer, coiled tubing, hollow rod, specialty metal pipe, special nonmetal pipe.

Natural gas production method the most according to claim 1, it is characterized in that, described insulated tubing includes having any one or two or more compound tube combined of the oil pipe of insulation, thermal insulation, heat insulation structural or function, coiled tubing, specialty metal pipe, special nonmetal pipe.

Natural gas production method the most according to claim 1, it is characterised in that comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

3) natural gas is allowed to rely on own temperature reducing pressure by regulating flow in well site.

Natural gas production method the most according to claim 4, it is characterized in that, described insulated tubing can allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate, or/and natural gas temperature after well site relies on own temperature reducing pressure by regulating flow can be allowed to be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C.

6. according to the natural gas production method described in claim 4 or 5, it is characterised in that the natural gas after also comprising the steps: reducing pressure by regulating flow is delivered to gas gathering station.

7. according to the natural gas production method described in claim 4 or 5, it is characterised in that: described reducing pressure by regulating flow includes well site surface throttling blood pressure lowering or well head reducing pressure by regulating flow.

Natural gas production method the most according to claim 7, it is characterised in that: described reducing pressure by regulating flow includes 1 grade of reducing pressure by regulating flow or more than 2 grades reducing pressure by regulating flows.

Natural gas production method the most according to claim 4, it is characterised in that: in step 3) before, in natural gas, first add antifreezing agent.

Natural gas production method the most according to claim 1, it is characterised in that: comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

3) natural gas is allowed to rely on own temperature to carry out reducing pressure by regulating flow first in well site；

4) the natural gas input gas-liquid separator after reducing pressure by regulating flow first will separate liquid and natural gas；

5) in isolated natural gas, antifreezing agent is added；

6) natural gas carrying antifreezing agent is allowed to rely on own temperature to carry out second time reducing pressure by regulating flow in well site.

11. natural gas production methods according to claim 10, it is characterised in that: the temperature after described reducing pressure by regulating flow first can ensure that natural gas dependence own temperature reducing pressure by regulating flow generates critical temperature and freezing point higher than hydrate and will not generate hydrate or ice in gas-liquid separator.

12. according to the natural gas production method described in claim 10 or 11, it is characterised in that: described reducing pressure by regulating flow first and second time reducing pressure by regulating flow are one-level or more than 2 grades reducing pressure by regulating flows.

13. natural gas production methods according to claim 10, it is characterised in that: described gas-liquid separator includes 1 gas-liquid separator or 2 more parallels or the gas-liquid separator of series connection.

14. natural gas production methods according to claim 1, it is characterised in that comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

3) in natural gas, antifreezing agent is added；

4) natural gas is allowed to rely on own temperature and underground heat repeatedly reducing pressure by regulating flow in buried gathering line between well site to gas gathering station.

15. natural gas production methods according to claim 14, it is characterised in that: described repeatedly reducing pressure by regulating flow can utilize big geothermal energy to allow the temperature of natural gas in-line be higher than 0 DEG C and less than the buried mean annual cost of gathering line between well site to gas gathering station or less than 10 DEG C.

16. natural gas production methods according to claim 14, it is characterised in that comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

3) in natural gas, antifreezing agent is added；

4) natural gas carrying antifreezing agent is allowed to rely on own temperature at well site reducing pressure by regulating flow；

5) natural gas after the reducing pressure by regulating flow of well site is allowed to rely on own temperature and underground heat repeatedly reducing pressure by regulating flow in buried gathering line between well site to gas gathering station.

17. natural gas production methods according to claim 16, it is characterised in that:

Described well site reducing pressure by regulating flow can allow natural gas temperature after reducing pressure by regulating flow generate critical temperature and higher than 0 DEG C higher than hydrate, and less than the buried mean annual cost of gathering line between local well site to gas gathering station or less than 10 DEG C；

Described repeatedly reducing pressure by regulating flow can utilize big geothermal energy to allow the temperature of natural gas in-line be higher than 0 DEG C and less than the buried mean annual cost of gathering line between well site to gas gathering station or less than 10 DEG C.

18. according to the natural gas production method described in claim 16 or 17, it is characterised in that:

Described well site reducing pressure by regulating flow includes 1 grade or more than 2 grades reducing pressure by regulating flows；

Described repeatedly reducing pressure by regulating flow includes between well site to gas gathering station more than 2 grades reducing pressure by regulating flows of optional position on buried gathering line.

19. natural gas production methods according to claim 4, it is characterised in that comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

3) natural gas is allowed to rely on own temperature at well site reducing pressure by regulating flow；

4) allow the natural gas after reducing pressure by regulating flow enter in the gas-liquid separator that well site is arranged and separate liquid and natural gas；

5) in isolated natural gas, antifreezing agent is added；

6) natural gas carrying antifreezing agent is allowed to rely on own temperature and underground heat repeatedly reducing pressure by regulating flow in buried gathering line between well site to gas gathering station.

20. natural gas production methods according to claim 4, it is characterised in that comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

3) natural gas is allowed to rely on own temperature reducing pressure by regulating flow in well site；

4) in the natural gas after reducing pressure by regulating flow, add antifreezing agent, then natural gas is delivered to gas gathering station.

21. natural gas production methods according to claim 4, it is characterised in that: with hot insulated line, natural gas is delivered to gas gathering station.

22. natural gas production methods according to claim 4, it is characterised in that: comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

4) natural gas after reducing pressure by regulating flow is transported in the gas-liquid separator that well site is arranged, by gas-liquid separator, natural gas is separated with liquid；

5) in isolated natural gas, antifreezing agent is added；

6) natural gas carrying antifreezing agent is fed directly to gas gathering station.

23. natural gas production methods according to claim 4, it is characterised in that:

2) natural gas is allowed to rise to well head by insulated tubing；

5) gathering line of isolated natural gas hot insulated line or insulation is delivered to gas gathering station.

24. natural gas production methods according to claim 23, it is characterised in that: described gas-liquid separator is 1 gas-liquid separator or 2 more parallels or/and the gas-liquid separator of series connection.

25. natural gas production methods according to claim 24, it is characterised in that: described gas-liquid separator and liquid outlet are incubated.

26. natural gas production methods according to claim 1, it is characterised in that comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

3) with hot insulated line, natural gas is delivered to gas gathering station；

4) natural gas is allowed to rely on own temperature reducing pressure by regulating flow in gas gathering station.

27. natural gas production methods according to claim 26, it is characterised in that:

Described insulated tubing can allow natural gas rise to the temperature of well head and generate critical temperature higher than hydrate, or/and the temperature after natural gas can be allowed to rely on own temperature, pressure and hot insulated line to be delivered to gas gathering station reducing pressure by regulating flow is not less than minimum operating temperature that natural gas line pipe fitting allowed or is not less than-20 DEG C；

Described hot insulated line can ensure that natural gas rely on own temperature, pressure to be delivered to gas gathering station reducing pressure by regulating flow after temperature be not less than minimum operating temperature that natural gas line pipe fitting allowed or be not less than-20 DEG C.

28. according to the natural gas production method described in claim 26 or 27, it is characterised in that: described reducing pressure by regulating flow is 1 grade of reducing pressure by regulating flow or more than 2 grades reducing pressure by regulating flows.

29. natural gas production methods according to claim 26, it is characterised in that: step 4) in, reducing pressure by regulating flow forward direction natural gas adds antifreezing agent.

30. natural gas production methods according to claim 1, it is characterised in that comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

3) in natural gas, antifreezing agent is added；

4) natural gas is allowed to rely on own temperature to be delivered to gas gathering station by gathering line buried between well site to gas gathering station after well site reducing pressure by regulating flow is cooled to 0.5～9 DEG C；

5) natural gas is inputted in the gas-liquid separator that gas gathering station is arranged, by gas-liquid separator, natural gas is separated with liquid；

6) allow isolated natural gas rely on own temperature after gas gathering station reducing pressure by regulating flow is cooled to 0.5～9 DEG C by pipelined between the buried station of gas gathering station to purification plant to natural gas purification processing factory.

31. natural gas production methods according to claim 30, it is characterised in that also comprise the steps: the natural gas reducing pressure by regulating flow entering natural gas purification processing factory is cooled to more than-8 DEG C.

32. according to the natural gas production method described in claim 30 or 31, it is characterized in that: the temperature that described insulated tubing can allow natural gas rise to well head generates critical temperature higher than hydrate, or/and natural gas can be allowed to rely on own temperature temperature after well site reducing pressure by regulating flow more than 10% to be not less than 0.5 DEG C.

33. natural gas production methods according to claim 30, it is characterised in that: described reducing pressure by regulating flow is 1 grade or more than 2 grades reducing pressure by regulating flows.

34. natural gas production methods according to claim 30, it is characterised in that comprise the steps:

2) natural gas is allowed to rise to well head by insulated tubing；

3) in natural gas, antifreezing agent is added；

6) in isolated natural gas, antifreezing agent is added；

7) allow isolated natural gas rely on own temperature after gas gathering station reducing pressure by regulating flow is cooled to 0.5～9 DEG C by pipelined between the buried station of gas gathering station to purification plant to natural gas purification processing factory.