CN112647857B

CN112647857B - Injection-production string and well completion method using same

Info

Publication number: CN112647857B
Application number: CN201910968537.XA
Authority: CN
Inventors: 何祖清; 赵金洲; 何同; 伊伟锴; 孙鹏; 彭汉修
Original assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Current assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Priority date: 2019-10-12
Filing date: 2019-10-12
Publication date: 2022-11-25
Anticipated expiration: 2039-10-12
Also published as: CN112647857A

Abstract

The invention provides an injection-production string and a well completion method using the same, wherein the injection-production string comprises a normally-open safety valve, a gas lift valve, a well flushing valve, a packer, a sitting short section and a tail pipe accessory which are sequentially connected from top to bottom through an oil pipe, and the injection-production string has multiple operation functions, can meet multiple requirements of injection-production operation of a gas storage reservoir by one-time input, simplifies the construction process and reduces the construction cost.

Description

Injection-production string and well completion method using same

Technical Field

The invention belongs to the field of oil and gas storage, and particularly relates to a multifunctional injection-production string for gas storage warehouse building and operation and a well completion method using the same.

Background

The underground gas storage is a main natural gas storage mode, 715 underground gas storage bases are built globally, the working gas amount is about 3930 hundred million, the natural gas consumption is 11%, and the underground gas storage is mainly distributed in Europe and North America. With the increasing proportion of natural gas in the energy consumption of China year by year, the underground gas storage becomes one of the key links of the safety supply of natural gas in recent years. 25 underground gas storage banks are built in China, the effective working gas amount is 117 hundred million, and the total consumption amount of the underground gas storage banks accounts for 5 percent of the total national consumption. The buried depth of foreign underground gas storage is generally more than 2000m, the structure is simple, the thickness of the reservoir is large, and the physical property is good; the geological conditions of reservoir building of gas reservoirs represented by 23 gas fields in China petrochemical industry are relatively poor, the burial depth is generally more than 300m, faults are many, the structure is complex, sedimentary facies becomes fast, the physical properties of reservoirs are poor, and the heterogeneity is strong.

The current injection and production pipe column has a single type and cannot meet the requirements of different functions and environments.

Disclosure of Invention

In view of some or all of the above technical problems in the prior art, the present invention provides an injection-production string and a well completion method using the same. The injection-production string has multiple operation functions, can meet multiple requirements of injection-production operation of the gas storage by one-time input, simplifies the construction process and reduces the construction cost.

According to one aspect of the invention, an injection-production tubular column is provided, which comprises a normally open safety valve, a gas lift valve, a well flushing valve, a packer, a landing nipple and a tail pipe accessory which are sequentially connected from top to bottom through an oil pipe.

In one embodiment, the packer and the lower landing nipple and the tail pipe accessory are firstly put into a shaft, after releasing, a safety valve, a gas lift valve and a flushing valve which are positioned above the packer are put into the shaft, and a cannula which can be inserted into a main body inner cavity of the packer is fixedly arranged on a tubing at the lower end of the flushing valve.

In one embodiment, the packer is configured as a retrievable hydraulically set packer capable of unsetting.

In one embodiment, a check valve is provided at the bottom of the inner cavity of the body of the packer, which is arranged to open when the cannula is back-inserted.

In one embodiment, one or more of a temperature sensor, a pressure sensor and a flow sensor selectively positionable at the landing nipple are also included.

In one embodiment, the emergency shutdown system further comprises a controller which is arranged on the ground and can be in signal connection with the safety valve, and the controller is configured to control the safety valve to be in emergency shutdown.

In one embodiment, the tubing, safety valve, gas lift valve, well cleanup valve, packer, and landing nipple are made of corrosion resistant material.

In one embodiment, an axially extending optical fiber cable is arranged on the outer wall of the oil pipe, the safety valve, the gas lift valve and the well flushing valve above the packer, and a grating temperature sensor and/or a grating pressure sensor and/or a grating stress sensor which can be in signal connection with the optical fiber cable are arranged on the optical fiber cable.

According to another aspect of the invention, there is provided a method of completing a well using the above-described injection and production string, comprising:

firstly, a packer, a lower setting nipple and a tail pipe accessory are put into a shaft, after the packer is put in place, the circulating well flushing is carried out to replace shaft heavy slurry to clean a reservoir stratum, then the packer is actuated to set, then the releasing is carried out,

and step two, a safety valve, a gas lift valve and a well flushing valve which are positioned above the packer are lowered into the shaft, so that a cannula on an oil pipe arranged at the lower end of the well flushing valve can be inserted into the inner cavity of the packer main body.

In one embodiment, the method further comprises a third step of filling the anticorrosion protection liquid into an oil casing annulus between the injection and production string and the casing, wherein the casing below the packer is made of anticorrosion materials.

Compared with the prior art, the invention has at least one of the following advantages that the requirements of gas storage reservoir multi-frequency gas injection, well shut-in, gas production and well repair maintenance can be met after the injection-production tubular column is completed through the serial arrangement of a plurality of tool pieces, the process aims of reservoir cleaning and reconstruction, dynamic monitoring, emergency shut-off abnormal control, multi-stage gas lift and the like can be realized, and the well completion method for the multiple production purposes of the gas storage reservoir can be realized through one tubular column.

Drawings

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic of a construction of a flow string according to the present invention;

the figures are not drawn to scale.

Detailed Description

The invention will be further explained with reference to the drawings.

Fig. 1 shows a production and injection string 100 according to the present invention. As shown in fig. 1, the injection-production string 100 comprises a normally open safety valve 3, a gas lift valve 4, a flushing valve 5, a packer 6, a landing nipple 7 and a tail pipe attachment 8 which are sequentially arranged from top to bottom through an oil pipe 1. After the injection and production string 100 is completed, the requirements of gas reservoir multi-frequency gas injection, well shut-in, gas production and well repair maintenance can be met, and the process purposes of reservoir cleaning and modification, dynamic monitoring, emergency shutdown abnormal control, oil casing corrosion prevention, multi-stage gas lift and the like can be realized, so that the well completion method for the multiple production purposes of the gas reservoir is realized through the injection and production string 100.

In one embodiment, the packer 6, with the landing nipple 7 and tailpipe attachment 8 below, is first run into the wellbore. And after the well is in place, circularly flushing the well to replace heavy slurry in the shaft to clean the reservoir, actuating the packer 6 to set, and then releasing the well. The safety valve 3, the gas lift valve 4 and the well flushing valve 5 are arranged in a shaft, and an insertion pipe is fixedly arranged on an oil pipe at the lower end of the well flushing valve 5 and can be inserted into the inner cavity of the main body of the packer 6. Thereby completing the running installation of the injection and production string 100. After the installation, the injection channel of the injection-production string 100 can be opened, fluid is injected from the oil pipe 1 to modify the reservoir or gas is injected according to the production scheme, and the well is closed after the injection process is finished. In addition, recovery can be carried out from the gas storage well according to the demand of natural gas peak regulation operation condition. Therefore, the pipe column 100 can realize injection and production of various functions of the gas storage, the construction process is simplified, and the construction cost is low.

The tubing 1 is used, among other things, to connect various downhole tools in the injection and production string 100. Tubing 1 runs tubing string 100 into the wellhead and provides a controlled fluid injection and production pathway for a single well.

The relief valve 3 is a fluid control valve, and is constructed in a normally open valve shape. The safety valve 3 can be in signal connection with a controller (not shown in the figure) arranged on the ground, so that when an abnormal condition occurs on the ground or in a well, the fluid is started and emergently shut off according to a real-time sensing signal, and the construction safety is ensured. It should be noted that the present application does not make any modifications to the safety valve 3 itself, and the safety valve 3 may be, for example, a NE type downhole safety valve of harebilton. Of course, the present application is not limited to the safety valve 3, and any safety valve 3 that can satisfy the use requirement may fall within the scope of the present application.

The gas lift valve 4 is a reverse gas lift switch tool arranged on the oil pipe 1 and is used for realizing that specific fluid is injected in the air through an oil sleeve ring and realizing that the drainage and recovery effects are improved through multi-stage gas lift. In the use process, one set or a plurality of sets of gas lift valves 4 can be arranged according to the actual requirement. Under the condition that a plurality of sets of gas lift valves 4 are arranged, the gas lift valves 4 are arranged in series to improve the gas lift effect.

The well flushing valve 5 is arranged on the oil pipe 1 and is positioned between the packer 6 and the gas lift valve 4, and is a switching tool for realizing the communication of an oil pipe sleeve and the up-and-down communication of the oil pipe 1 and is used for realizing the technical purposes of reverse circulation well flushing and well killing. For example, during gas injection or production, fluid can be injected from the annulus according to production requirements, the flushing valve 5 is opened by using the pressure difference that the pressure of the annulus is greater than the internal pressure of the oil pipe, and the fluid is injected from the annulus into the oil pipe so as to flush or kill the well

Preferably, the packer 6 is configured as a retrievable, hydraulically set packer, enabling unsetting and thus lifting of the tubular string 100 out of the well head. After being run in place, the packer 6 is above the reservoir and is used to seal off the wellbore annulus between the string 100 and the casing 2. In addition, the packer also functions to suspend the injection and production string 100. In another preferred embodiment, a check valve (not shown) is designed at the bottom of the inner cavity of the body of the packer 6. The check valve has the function of reservoir shutoff fluid and is used for guaranteeing the requirements of upper workover operation. Specifically, during the run in of the second running string, the stinger is inserted into the inner cavity of the packer 6 and the check valve is opened, thereby enabling communication of the inner cavity of the production string 100 there. On the contrary, in the work of repairing well, after the safety valve 3, the gas lift valve 4, the well flushing valve 5, the insert pipe and the like on the upper part of the packer 6 are lifted out, the check valve is closed to block the fluid, and the safety is ensured. The packer 6 can also be a packer with higher suspension capacity and temperature and pressure resistance in the prior art, so that the high-pressure-level injection and production requirements of the gas reservoir are met. After running the string 100, the packer 6 may be activated by pumping to set to seal off the wellbore annulus. And the setting of the packer 6 can be released when it is desired to raise or move the string 100 out of position.

The setting of the short section of sitting 7 is at the lower extreme of packer 6, and self is a kind of inside diameter and reduces, has the short section instrument of step change. After the pipe string 100 is put into the well, a soluble ball is put into the inner cavity of the pipe string 100 and falls on the landing nipple 7 to block the inner cavity of the pipe string 100, and at the moment, the packer 6 can be actuated to be set in a pressure fluid pumping mode. In addition, the landing nipple 7 can also be used for hanging a ball rod to unidirectionally block fluid, and can also be used for selectively hanging a downhole multi-parameter testing instrument, such as one or more of a temperature sensor, a pressure sensor and a flow sensor. Therefore, in the gas injection or recovery process of the pipe column 100, different underground testing instruments can be put in the position of the landing nipple 7 to monitor the process parameters such as temperature, pressure, flow and the like of different positions of the underground part and the shaft.

The tailpipe attachment 8 is a downhole tool having a connecting channel and a guiding function, etc. mounted on the bottom of the pipe string.

As shown in fig. 1, an optical fiber cable 10 extending from top to bottom is further disposed on the outer wall of the injection-production string 100, and a grating temperature sensor 11 capable of signal connection with the optical fiber cable 10 is disposed on the optical fiber cable 10 for measuring the downhole temperature. Of course, according to the engineering requirement, a grating pressure sensor 12 and a grating stress sensor 13 connected with the optical fiber cable 10 in signal connection can be further arranged on the optical fiber cable for respectively monitoring the underground pressure and the stress of the injection-production string 100 in real time. On one hand, the arrangement utilizes the advantages of small size, light weight, high density, large capacity, full optical transmission, electromagnetic interference resistance, service life of more than 20 years and the like of the optical fiber cable, and is suitable for the requirement of long-term use of the gas storage injection-production string 100. On the other hand, the optical cable utilizes a photosensitive element or material to convert the measured parameters into a sensing technology of corresponding optical signals, can realize real-time monitoring of the underground injection-production temperature, pressure and injection-production string 100, and provides reference for optimizing the injection-production process, adjusting the injection-production parameters and controlling the salinity in the injection-production process.

Preferably, in the actual use process, the grating temperature sensor 11, the grating pressure sensor 12 and the grating stress sensor 13 can be arranged at different positions according to requirements. For example, a grating temperature sensor 11 is disposed at intervals (e.g., about 500 meters) on the fiber optic cable 10 according to the actual engineering requirements to measure the temperature at different depths downhole. And the grating stress sensors 13 are arranged at the positions with complicated stress conditions, such as the well mouth at the upper end of the injection-production pipe column 100, above the packer 6 and the like, so as to monitor the stress state of the injection-production pipe column 100 and ensure the safety and the fatigue strength of the injection-production pipe column 100. The grating pressure sensors 12 may also be arranged one at a distance (e.g. about 500 meters).

The optical fiber cable 10 is a cable sheathed outside the optical fiber and extends along the outer wall of the injection/production string 100. It is easy to understand that the optical fiber cable 10 can be arranged on the outer wall of the safety valve 3, the gas lift valve 4 and the well flushing valve 5, and can also extend through the safety valve 3 and other components up and down without affecting the operation of the safety valve 3, the gas lift valve 4 and the well flushing valve 5 according to the actual situation. It is particularly noted that the optical fibre cable 10 may extend to the upper end of the packer 6, but may also be suitably selected to extend downwardly through the packer 6 without interfering with the operation of the packer 6 itself, and in the presence of a crossover space. In addition, if the optical fiber cable 10 is also provided at the lower end of the packer 6, since the injection and production string 100 can be completed by two-trip, it can be understood that the optical fiber cable 10 is also completed by two-trip in a matched type, and the splicing connection is made at the adjacent ends to form the connected optical fiber cable 10. Such connection methods are known in the prior art and will not be described herein.

The method of completing a well using the tubing string 100 is described in detail below with respect to FIG. 1.

Specifically, the injection and production string 100 is run into the wellbore by two runs. Specifically, the packer 6, the setting nipple 7 and the tail pipe accessory 8 below the packer are firstly put into a shaft, after the packer is put in place, the circulating well flushing is carried out to replace shaft heavy slurry to clean a reservoir stratum, then the packer 6 is actuated to set, and then the releasing is carried out. Then, the safety valve 3, the gas lift valve 4 and the flushing valve 5 are lowered into the wellbore so that a cannula on the tubing disposed at the lower end of the flushing valve 5 can be inserted into the body lumen of the packer 6. And then gas injection or gas storage and recovery can be carried out from the reservoir according to the construction requirements, so that the requirement of peak regulation operation of the gas storage is met.

In the gas injection or recovery process of the pipe column 100, underground test instruments with different parameters can be put in the position 7 of the landing nipple to monitor the process parameters such as temperature, pressure, flow and the like of different positions of the underground part and the shaft, and a basis is provided for production control optimization.

If the ground wellhead is out of control, maintained or in other emergency situations, the safety valve 2 can realize emergency shutoff according to ground instructions to prevent gas from going upwards and prevent blowout. In addition, when the upper pipe column of the multifunctional packer 6 needs maintenance and updating operation, a ball rod can be thrown in the oil pipe 1 and is hung on the landing nipple 7 to achieve fluid blocking, and the purposes of safe production and maintenance are met.

When tools and oil pipes need to be maintained and updated, the pipe column 100 above the packer 6 can be disconnected with the main body of the packer 6 through the insertion pipe, and the bottom of the packer 6 has a fluid one-way blocking function, so that the function of well repairing operation under pressure can be met when the upper pipe column is lifted out of a shaft to maintain and update the tools and the oil pipes.

The tubular column can be disconnected with the packer 6 and inserted back through the insertion pipe above the multifunctional packer 6, the expansion compensation effect of the tubular column 100 under the high-pressure alternating load condition of the gas storage can be achieved, the pressure resistance and the connection safety of the injection and production tubular column 100 are guaranteed, and the service life of the injection and production tubular column 100 is prolonged.

In the gas injection or gas production process, fluid can be injected from the annular space between the oil pipe 1 and the casing pipe 2 according to production requirements, and the fluid returns from the oil pipe 1 through the reverse circulation kill-job well flushing valve 5 to realize the well flushing or killing effect.

In the pipe column 100, the oil pipe 1, the safety valve 3, the gas lift valve 4, the well flushing valve 5, the packer 6, the landing nipple 7 and a sleeve below the packer 6 can be made of anti-corrosion materials. For example, the corrosion-resistant material can be one of high-strength corrosion-resistant alloys such as 13Cr, super13Cr, 718, 925 and the like. Non-anticorrosive material can be chooseed for use to the well head sleeve pipe more than 6 packers, and in 6 setting backs of packer, also fill anticorrosive protection liquid in the oil jacket annular space, realize that the oil jacket annular space is anticorrosive, reduce cost, the whole life cycle of extension individual well and the integrality of guarantee pit shaft. For example, the preservative protective solution is composed of components such as a slow release agent and a chemical preservative agent, and can be nitrite, tungstate and the like.

According to different working conditions, the injection-production string 100 can comprise a plurality of sets of gas lift valves 4 connected in series so as to achieve the function of gas lift liquid drainage and gas production and improve the effect of water drainage and gas production of the gas storage well.

In the application, the injection-production string 100 is provided with downhole tools such as a packer 6 and the like, and forms a state of casing inner closed completion, so that fluid can be injected from the string 100 to perform irregular cleaning, acidification, fracturing and other transformation measures on a reservoir stratum, and the injection and production effects of a single well are improved.

According to the process method, the gas production string 100 is put in, so that the main injection and production functions of injection and well completion in a production scheme pipe and recovery as required can be realized, and the well completion process with the process purposes of reservoir cleaning and reconstruction, dynamic monitoring, emergency shutdown abnormity control, oil casing corrosion prevention, multi-stage gas lift drainage assisting function, string compensation protection function, no-killing well and no-blowout operation and the like can also be realized.

In the present application, the terms "upper" and "lower" are used with reference to the actual operating orientation of the injection and production string 100.

The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily make changes or variations within the technical scope of the present invention disclosed, and such changes or variations should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An injection and production string is characterized by comprising a normally open safety valve, a gas lift valve, a well flushing valve, a packer, a sitting short section and a tail pipe accessory which are sequentially connected from top to bottom through an oil pipe, wherein the oil pipe is provided with a plurality of sets of gas lift valves, the gas lift valves are connected in series, the gas lift valves are reverse gas lift switching tools arranged on the oil pipe and are used for realizing the injection of specific fluid into the air through an oil sleeve ring to realize multi-stage gas lift, the well flushing valve can realize the communication of an oil pipe sleeve and the up-and-down communication of the oil pipe and is used for realizing the technical purposes of reverse circulation well flushing and well killing, the outer walls of the oil pipe, the safety valve, the gas lift valves and the well flushing valve above the packer are provided with optical fiber cables extending axially, and the optical fiber cables are provided with optical cable temperature sensors which can be in signal connection with the optical fiber cables and are used for measuring the temperature in the pit, grating pressure sensors for monitoring the pressure under the well in real time and grating stress sensors for monitoring the injection and production string in real time, the grating temperature sensors are axially arranged at intervals, the grating pressure sensors are axially arranged at intervals, the grating stress sensors are arranged at the upper end wellhead and at the positions above the packer, the lower landing nipple and the tail pipe accessory are firstly put into a shaft, after releasing, the safety valve, the gas lift valve and the flushing valve which are positioned above the packer are put into the shaft, an insertion pipe which can be inserted into the main body inner cavity of the packer is fixedly arranged on an oil pipe at the lower end of the flushing valve, the insertion pipe can be inserted into the main body inner cavity of the packer, so that the injection and production pipe column is put into and installed, and an injection channel of the injection and production pipe column can be opened after the installation is finished, injecting fluid from the oil pipe to modify a reservoir or injecting gas according to a production scheme, closing the well after the injection process is finished, and performing recovery from the gas storage well according to the requirement of natural gas peak regulation operation condition, so that the injection-production pipe column can realize injection and production of multiple functions of the gas storage; the packer is constructed into a removable hydraulic setting packer and can realize deblocking so as to lift the tubular column out of a well head, a check valve is designed at the bottom of an inner cavity of a body of the packer and has the function of reservoir shutoff fluid, an insertion pipe is inserted into the inner cavity of the packer in the process of descending the second conveying pipe string, the check valve is opened so as to realize communication of the inner cavity of the gas production tubular column at the position, and after a safety valve, a gas lift valve, a well flushing valve and the insertion pipe on the upper portion of the packer are lifted out in well workover treatment, the check valve is closed so as to block the fluid.

2. The injection and production string of claim 1, further comprising one or more of a temperature sensor, a pressure sensor, and a flow sensor selectively positionable at the landing nipple.

3. A string according to claim 1 or claim 2, further comprising a controller at the surface in signal communication with the safety valve, the controller being configured to control the safety valve to shut off emergently.

4. An injection and production string according to claim 1 or 2, wherein the tubing, the safety valve, the gas lift valve, the flushing valve, the packer and the landing nipple are made of a corrosion resistant material.

5. A method of completing a well using the injection and production string of any of claims 1 to 4, comprising:

firstly, the packer and the lower setting nipple and the tail pipe accessory are put into a shaft, after the packer is put in place, the circulating well flushing is carried out to replace shaft heavy slurry to clean a reservoir stratum, then the packer is actuated for setting, and then the releasing is carried out,

and step two, the safety valve, the gas lift valve and the well flushing valve which are positioned above the packer are lowered into the well bore, so that a cannula on an oil pipe arranged at the lower end of the well flushing valve can be inserted into the inner cavity of the packer main body.

6. The well completion method of claim 5, further comprising, step three, injecting a corrosion protection fluid into an oil casing annulus between the injection and production string and the casing, wherein the casing below the packer is made of a corrosion protection material.