CN114233285A - Natural gas hydrate exploitation test method and test device - Google Patents
Natural gas hydrate exploitation test method and test device Download PDFInfo
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- NMJORVOYSJLJGU-UHFFFAOYSA-N methane clathrate Chemical compound C.C.C.C.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O NMJORVOYSJLJGU-UHFFFAOYSA-N 0.000 title claims abstract description 87
- 238000012360 testing method Methods 0.000 title claims abstract description 25
- 238000010998 test method Methods 0.000 title claims abstract description 19
- 238000006243 chemical reaction Methods 0.000 claims abstract description 89
- 238000004519 manufacturing process Methods 0.000 claims abstract description 79
- 239000007789 gas Substances 0.000 claims abstract description 73
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 71
- 238000000034 method Methods 0.000 claims abstract description 67
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 60
- 230000008569 process Effects 0.000 claims abstract description 32
- 238000005065 mining Methods 0.000 claims abstract description 27
- 239000007788 liquid Substances 0.000 claims abstract description 23
- 230000007613 environmental effect Effects 0.000 claims abstract description 4
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- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical class C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 description 3
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/01—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells specially adapted for obtaining from underwater installations
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
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Abstract
The invention provides a natural gas hydrate exploitation test method and a natural gas hydrate exploitation test device, wherein the method comprises the following steps: designing an exploitation scheme from different depressurization gradients and different depressurization rates to target bottom hole flowing pressure based on a methane hydrate phase equilibrium curve according to the pressure and the ambient temperature of a hydrate reservoir in a target area; preparing methane hydrate by using a high-pressure reaction kettle, and gradually increasing the generation temperature to the mining temperature in a step temperature increasing manner, wherein the mining temperature is the environmental temperature; after the temperature of the high-pressure reaction kettle is balanced, controlling the depressurization step length of a PID electronic controller and the proportion, the integral and the differential of the controller according to a preset depressurization gradient and a depressurization rate, and reducing the pressure at the exploitation wellhead of the high-pressure reaction kettle to the target bottom flowing pressure at a constant depressurization rate and a depressurization gradient to realize the exploitation of the natural gas hydrate with controllable depressurization; the methane gas and water produced in the mining process are collected in real time, and the liquid production amount and the water-gas ratio are calculated according to a gas-liquid quantitative method, so that an optimized depressurization mining scheme is provided.
Description
Technical Field
The invention relates to the technical field of natural gas hydrate exploitation, in particular to a natural gas hydrate exploitation test method and a natural gas hydrate exploitation test device.
Background
Natural gas hydrate is a solid crystalline substance, mainly composed of water molecules and methane gas molecules, and is usually located in permafrost layers in low-temperature and high-pressure environments and on the seabed near continental stands. Methane hydrate is due to its enormous resource size (3000 billions of cubic meters) and high energy storage capacity (170 CH)4/H2O), and only H is released during combustion2O and CO2Is considered as the main clean energy source in the future. At present, the pilot production engineering of methane hydrate is developed in succession in various countries, and the exploitation method comprises a depressurization method, a heat injection method, an inhibitor injection method and CO2Substitution method. Among them, the drawdown method is considered as the most effective method for methane hydrate exploitation, and compared with the thermal stimulation method, the rapid drawdown of the reservoir is wider than the hydrate unstable region caused by increasing the heat energy. Meanwhile, in the past, on-site production tests in Mallik, Nankai Haicho, Japan, and the south Hicishi Huohy area of China have demonstrated the feasibility of hydrate reservoir depressurization production technology.
However, significant technical challenges remain in achieving long-term and economical production of methane hydrates, such as low gas production rates, excessive water production, uncontrollable sand production, and the like. This poor production behavior is directly related to two key process variables, namely pressure drop gradient and rate. It controls the rate of hydrate decomposition and the flow of multiphase fluids in reservoirs containing hydrate deposits. At present, the bottom hole pressure is difficult to accurately control in large-scale production test, and meanwhile, the laboratory-scale methane hydrate depressurization exploitation method and device only control the bottom hole flowing pressure at a set pressure based on a one-way valve, and the problem of large bottom hole flowing pressure fluctuation is still not effectively solved. Meanwhile, the existing field production test results show that the faster the pressure drop rate and the higher the pressure drop degree of all the production wells, the faster the gas production rate. Currently, there is still a lack of criteria for selection of a depressurization gradient and knowledge of the effect of depressurization rate on fluid production characteristics. Most laboratory size studies are focused only on the analysis of the overall fluid production, and less is known about the rate of fluid production and recovery (i.e., drawdown and constant bottom hole drawdown) for each phase. Meanwhile, the pressure reduction is usually deep and rapid in the current laboratory scale simulation, and although the improvement of the hydrate decomposition rate and the gas production rate is facilitated, because the hydrate reservoir usually exists in a high saturated water environment, when the pressure reduction rate is high, the phenomena of mass water production and intermittent sand production can occur, so that the wellhead blockage can be caused, and the flow safety is influenced.
The prior art lacks a controllable depressurization natural gas hydrate exploitation and gas-liquid output quantitative experimental method.
The above background disclosure is only for the purpose of assisting understanding of the concept and technical solution of the present invention and does not necessarily belong to the prior art of the present patent application, and should not be used for evaluating the novelty and inventive step of the present application in the case that there is no clear evidence that the above content is disclosed at the filing date of the present patent application.
Disclosure of Invention
The invention provides a natural gas hydrate exploitation test method and a natural gas hydrate exploitation test device for solving the existing problems.
In order to solve the above problems, the technical solution adopted by the present invention is as follows:
a natural gas hydrate exploitation test method comprises the following steps: s1: designing different depressurization gradients P according to the pressure and the ambient temperature of a reservoir containing hydrate sediments in a target area and based on a phase equilibrium curve of methane hydrateGDifferent decompression rates vGDownhole flow pressure to target PB(ii) a S2: preparing methane hydrate by adopting a high-pressure reaction kettle and heating the methane hydrate from a generation temperature T in a gradient heating mode1Gradually increased to the mining temperature TwThe production temperature is the ambient temperature T of the hydrate deposit-containing reservoir in the target areaw(ii) a S3: after the temperature of the high-pressure reaction kettle is completely balanced, the pressure reduction step length and the pressure reduction rate of the PID electronic controller are sequentially controlled according to the pressure reduction gradient and the pressure reduction rate which are designed in advanceThe proportion P, the integral I and the differential D of the system are used for reducing the pressure at the production wellhead of the high-pressure reaction kettle to the target bottom flowing pressure at the pressure reduction gradient and the pressure reduction rate and producing in real time; s4: and respectively collecting methane gas and water produced in the depressurization exploitation process, obtaining the gas-liquid output and the saturation of three phases of methane hydrate, water and methane gas in the high-pressure reaction kettle, and determining the depressurization gradient, the depressurization rate and the target bottom hole flowing pressure for exploiting the hydrate-containing sediment reservoir stratum in the target area.
Preferably, the sediment pore water pressure P is calculated according to the depth of the hydrate-containing sediment reservoir in the target area from the sea levelw：
Pw＝Patm+ρwgh×10-6
Wherein, PatmIs atmospheric pressure in MPa; rhowIs the density of seawater, and has unit of kg/m3(ii) a g is the acceleration of gravity in m/s2(ii) a h is the depth of the seabed sediment from the sea level, and the unit is m;
calculating the environmental temperature T according to the depth of the hydrate-containing sediment reservoir of the target area from the sea levelw：
Tw＝a×hb
Wherein h is the depth of the seabed sediment from the sea level and the unit is m; a and b are empirical parameters of the reservoir temperature of the target hydrate deposit;
stabilizing the production temperature at the ambient temperature TwThen, according to a methane hydrate phase equilibrium curve, the pore water pressure P of the reservoir containing hydrate deposits in the target area is measuredwThe depressurization gradient P is designed from the methane hydrate stable regionGThe rate of depressurization vGLowering to the target bottom hole flow pressure PB。
Preferably, the production temperature is the ambient temperature T of the hydrate deposit-containing reservoir in the target zonewBefore pressure-reducing mining, temperature gradients (T)w-T1) N, dividing the methane hydrate into n steps from the generation temperature T1Gradually increasing to the mining temperature Tw(ii) a Wherein n is a positive integer and has a value in the range of 2-5.
Preferably, the pressure reduction step length of the PID electronic controller and the proportion P, the integral I and the derivative D of the controller are controlled, and the pressure at the production wellhead of the high-pressure reaction kettle is reduced to the target bottom flowing pressure by the pressure reduction gradient and the pressure reduction rate according to the following formula:
wherein, KpIs a proportionality coefficient, TiTo integrate the time constant, TdE (t) is a deviation value of the target bottom hole flow pressure and the pressure at the production wellhead of the high-pressure reaction kettle; ki＝Kp/TiIs the integral coefficient, Kd＝Kd/TdIs a differential coefficient;
Kpe (t) is a proportional term, namely, the deviation value of the pressure at the production wellhead of the high-pressure reaction kettle and the target bottom hole flowing pressure is proportionally adjusted;
Preferably, the methane gas is collected with a gas storage tank;
the volume of methane gas collected is expressed as: vGR＝V17+V18-Vw
Wherein, V17Volume of the gas-water separator, V18Is the volume of the gas storage tank, VwIs the water yield, expressed as mwG/ρw，mwGMeasured by an electronic scale for the water production mass, pwIs the density of water, 1g/cm3；
The molar amount of methane gas collected is expressed as: n isGR＝PGRVGR/ZGR/R/TGR
Wherein, PGRFor gas tank pressure, ZGRIs the gas compression coefficient, R is the gas constant, 8.314J/(mol. K), TGRIs the temperature of the gas storage tank;
the molar amount of water collected was: n iswG=mwG/Mw
Wherein M iswThe molar mass of water is 18 g/mol.
Preferably, the methane gas n in the high-pressure reaction kettle in the hydrate decomposition process is calculated according to the collected molar amount of the water and the molar amount of the methane gasgN waterwAnd methane hydrate nMHMolar amount of (a):
ng＝ng0+nc-nGR
nw＝nwO+NHnC-nWR
nMH＝nMH0-nc
wherein n isg0Is the initial gas molar quantity, n, of the high-pressure reaction kettlew0Is the initial water molar weight, n, of the high-pressure reaction kettleMH0Is the initial methane hydrate molar quantity, N, of the high-pressure reaction kettleHIs the hydration number of methane hydrate, ncIs the molar amount of decomposed methane hydrate;
calculating the volume V of water, methane gas and methane hydrate in the high-pressure reaction kettle in the decomposition process of the hydrateg、Vw、VMH:
Vg＝ngρg
Vw＝nwρw
VMH＝nMHρMH
Calculating the saturation S of the water, the methane gas and the methane hydrate in the high-pressure reaction kettle in the decomposition process of the hydrateg、Sw、SMH：
Sg＝Vg/(Vg+Vw+VMH)
Sw＝Vw/(Vg+Vw+VMH)
SMH＝VMH/(Vg+Vw+VMH)。
Preferably, the method further comprises the following steps: and dynamically adjusting the flow rate of a pipeline in front of a valve of the PID electronic controller according to the real-time quantitative gas-liquid output curve and adjusting three parameters of proportion P, integral I and differential D of the PID electronic controller in real time.
The invention also provides a natural gas hydrate exploitation test device for realizing the method, which comprises a high-pressure reaction unit, a controllable depressurization unit, a collection unit, a data acquisition unit and a processing unit which are connected in sequence; the high-pressure reaction unit comprises a high-pressure reaction kettle and is used for generating and storing a natural gas hydrate sediment reservoir; the controllable pressure reduction unit is used for reducing the pressure at the production wellhead of the high-pressure reaction kettle to a target bottom flowing pressure through a constant pressure reduction rate by a PID electronic controller; the data acquisition unit is used for receiving temperature signals and pressure signals in the mining process in real time and transmitting the temperature signals and the pressure signals to the processing unit; and the processing unit is used for receiving the data of the data acquisition unit, acquiring the pressure at the exploitation wellhead of the high-pressure reaction kettle and controlling the PID electronic controller according to the data and the pressure at the exploitation wellhead of the high-pressure reaction kettle.
Preferably, the controllable depressurization unit comprises a pressure sensor, a manual valve, a pressure control valve, a PID electronic controller and an air compressor, wherein the pressure sensor is used for monitoring a pressure signal at a mining wellhead of the kettle body in the mining process, the pressure signal is bottom hole flow pressure in a mining test, and the pressure signal is transmitted to the PID electronic controller; the manual valve is positioned between the hydrate high-pressure reaction kettle and the pressure control valve, the pressure reduction exploitation takes the manual valve as a starting point, and the pressure control valve reduces the pressure at the exploitation wellhead of the high-pressure reaction kettle to the target bottom flowing pressure at a constant pressure reduction gradient and pressure reduction rate through a PID (proportion integration differentiation) electronic controller; the air compressor is used to power the PID electronic controller.
Preferably, the collecting unit is a gas-liquid output real-time quantifying unit and comprises a gas-water separator, a gas collecting tank, an electronic scale, a pressure sensor and a temperature sensor; the front and the back of the gas-water separator are respectively connected with the pressure control valve and the gas collecting tank and are arranged on the electronic scale, and the liquid output in the pressure reduction exploitation process is obtained in real time through the electronic scale; the gas collection tank is provided with the pressure sensor and the temperature sensor, and the real-time gas production is obtained through the processing unit.
The invention has the beneficial effects that: provides a natural gas hydrate exploitation test method and a natural gas hydrate exploitation test device, realizes controllable depressurization by determined depressurization gradient and depressurization rate, and designs various depressurization gradients PGDifferent decompression rates vGAnd selecting the depressurization gradient, the depressurization rate and the target bottom hole flow pressure which are most suitable for exploiting the hydrate-containing sediment reservoir in the target area, so as to provide favorable reference for actual exploitation.
Furthermore, the method can realize quantitative evaluation of real-time liquid production behaviors of the reservoir in a depressurization stage and a stable bottom hole flowing pressure stage.
Furthermore, the test method and the test result can expand the understanding of the difference of water production and gas production of the hydrate deposit, and provide guidance for the optimization of a depressurization method and the evaluation of the production potential of the natural gas hydrate in future hydrate experiments and hydrate reservoir field production tests.
Drawings
Fig. 1 is a schematic diagram of a natural gas hydrate production test method in an embodiment of the present invention.
FIG. 2 is a phase equilibrium diagram of methane hydrate in an example of the present invention.
FIG. 3 is a schematic diagram of the pressure evolution process in the depressurization mining according to the embodiment of the invention.
Fig. 4 is a schematic diagram of a natural gas hydrate production testing apparatus according to an embodiment of the present invention.
FIG. 5 is a schematic view showing the distribution of temperature sensors in the autoclave in the example of the present invention.
FIGS. 6(a) to 6(c) are schematic diagrams showing the experimental results when the bottom hole flowing pressure is 3MPa in the example of the present invention.
FIGS. 7(a) to 7(c) are graphs showing the results of experiments conducted under the bottom hole pressure of 5MPa in the examples of the present invention.
The system comprises a data acquisition instrument 1, a computer 2, a pressure sensor 3, an internal pressure sensor 4, a sand prevention device 5, a manual valve 6, a top pressure sensor 7, a pressure control valve 8, a PID electronic controller 9, a pressure sensor 10, a temperature sensor 11, a bottom pressure sensor 12, a temperature sensor 13, a constant-temperature water bath circulating pump 14, an air compressor 15, an electronic scale 16, an air-water separator 17, a gas collection tank 18, an air release valve 19, a HBS high-pressure reaction kettle 20 and a temperature sensor 21.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the embodiments of the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element. In addition, the connection may be for either a fixing function or a circuit connection function.
It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the embodiments of the present invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be in any way limiting of the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "a plurality" means two or more unless specifically limited otherwise.
As shown in fig. 1, the present invention provides a natural gas hydrate production test method, including the following steps:
s1: designing different depressurization gradients P according to the pressure and the ambient temperature of a reservoir containing hydrate sediments in a target area and based on a phase equilibrium curve of methane hydrateGDifferent decompression rates vGDownhole flow pressure to target PB；
S2: preparing methane hydrate by adopting a high-pressure reaction kettle and heating the methane hydrate from a generation temperature T in a gradient heating mode1Gradually increased to the mining temperature TwThe production temperature is the ambient temperature T of the hydrate deposit-containing reservoir in the target areaw；
S3: after the temperature of the high-pressure reaction kettle is completely balanced, controlling the depressurization step length of a PID electronic controller and the proportion P, the integral I and the differential D of the controller according to the depressurization gradient and the depressurization rate which are designed in advance, and reducing the pressure at the exploitation wellhead of the high-pressure reaction kettle to the target bottom flowing pressure according to the depressurization gradient and the depressurization rate and carrying out real-time exploitation;
s4: and respectively collecting methane gas and water produced in the depressurization exploitation process, obtaining the gas-liquid output and the saturation of three phases of methane hydrate, water and methane gas in the high-pressure reaction kettle, and determining the depressurization gradient, the depressurization rate and the target bottom hole flowing pressure for exploiting the hydrate-containing sediment reservoir stratum in the target area.
It is understood that the drawdown gradient is the pressure differential from the reservoir original pressure down to the target bottom hole flow pressure, in one particular embodiment from 14MPa down to 5MPa, with a drawdown gradient of 9 MPa; the drawdown rate is the rate at which the reservoir pressure is reduced from the reservoir original pressure to the target bottom hole flow pressure, in one embodiment from 14MPa to 5MPa for 1 hour, and the drawdown rate is 9 MPa/hr.
The method of the invention designs different decompression gradients PGDifferent decompression rates vGDownhole flow pressure to target PBControllable depressurization is realized through the determined depressurization gradient and depressurization rate, and various depressurization gradients P are designedGDifferent decompression rates vGAnd selecting the depressurization gradient, the depressurization rate and the target bottom hole flow pressure which are most suitable for exploiting the hydrate-containing sediment reservoir in the target area, so as to provide favorable reference for actual exploitation.
The method can realize quantitative evaluation of the real-time liquid production behavior of the reservoir in the depressurization stage and the stable bottom hole flowing pressure stage.
The test method and the result of the invention can expand the understanding of the difference of water production and gas production of the hydrate deposit, and provide guidance for the optimization of the depressurization method and the evaluation of the production potential of the natural gas hydrate in future hydrate experiments and hydrate reservoir field production tests.
In one embodiment of the present invention, the depressurization gradient can be a single stage depressurization, a multi-stage depressurization; in one specific embodiment, the production temperature is 10 deg.C, the depressurization rate is 8MPa/hr, and the bottom hole flow pressure is 5 MPa.
In one embodiment of the invention, sediment pore water pressure P is calculated according to the depth of the hydrate-containing sediment reservoir in the target area from the sea levelw：
Pw＝Patm+ρwgh×10-6
Wherein, PatmIs atmospheric pressure in MPa; rhowIs the density of seawaterIs located in kg/m3(ii) a g is the acceleration of gravity in m/s2(ii) a h is the depth of the seabed sediment from the sea level in m.
Calculating the environmental temperature T according to the depth of the hydrate-containing sediment reservoir of the target area from the sea levelw：
Tw＝a×hb
Wherein h is the depth of the seabed sediment from the sea level and the unit is m; a and b are empirical parameters of the reservoir temperature of the target hydrate deposit;
stabilizing the production temperature at the ambient temperature TwThen, according to a methane hydrate phase equilibrium curve, the pore water pressure P of the reservoir containing hydrate deposits in the target area is measuredwThe depressurization gradient P is designed from the methane hydrate stable regionGThe rate of depressurization vGLowering to the target bottom hole flow pressure PB。
As shown in fig. 2, is a phase equilibrium diagram for methane hydrate.
Fig. 3 is a schematic diagram of a pressure evolution process in depressurization mining according to an embodiment of the present invention, wherein different depressurization rates and depressurization gradients are developed in a test process to explore the influence of the depressurization rates and the depressurization gradients on hydrate mining.
In one embodiment of the invention, the production temperature is the ambient temperature T of the hydrate deposit-containing reservoir in the target zonewBefore pressure-reducing mining, temperature gradients (T)w-T1) N, dividing the methane hydrate into n steps from the generation temperature T1Gradually increasing to the mining temperature Tw；
Wherein n is a positive integer and has a value in the range of 2-5.
In the invention, the heating in the high-pressure reaction kettle adopts water bath heating at the periphery of the kettle body, and in the heating process, the temperature of the inner ring and the outer ring of the kettle is firstly raised and then the temperature is raised, so that the disturbance caused by temperature difference at different positions in the heating process can be reduced by step heating, and in a preferred embodiment, the value of n is 2.
In one embodiment of the invention, the depressurization step length of the PID electronic controller and the proportion P, the integral I and the derivative D of the controller are controlled to realize the pressure reduction of the production wellhead of the high-pressure reaction kettle to the target bottom stream pressure by the depressurization gradient and the depressurization rate according to the following formula:
it will be appreciated that the buck step corresponds to the buck gradient, and the proportion P, the integral I and the derivative D of the controller correspond to the buck rate.
Wherein, KpIs a proportionality coefficient, TiTo integrate the time constant, TdE (t) is a deviation value of the target bottom hole flow pressure and the pressure at the production wellhead of the high-pressure reaction kettle; ki＝Kp/TiIs the integral coefficient, Kd＝Kd/TdIs a differential coefficient;
Kpe (t) is a proportional term, namely, the deviation value of the pressure at the exploitation wellhead of the high-pressure reaction kettle and the target bottom flowing pressure is proportionally adjusted, so that the function of constant depressurization rate in depressurization exploitation can be realized;
In one embodiment of the invention, a gas-water separator is used to collect the produced water, and an electronic scale is used to measure the weight of the collected water; collecting the methane gas by using a gas storage tank;
the volume of methane gas collected is expressed as: vGR＝V17+V18-Vw
Wherein, V17Volume of the gas-water separator, V18Is the volume of the gas storage tank, VwIs the water yield, expressed as mwG/ρw，mwGMeasured by an electronic scale for the water production mass, pwIs the density of water, 1g/cm3；
The molar amount of methane gas collected is expressed as: n isGR＝PGRVGR/ZGR/R/TGR
Wherein, PGRFor gas tank pressure, ZGRIs the gas compression coefficient, R is the gas constant, 8.314J/(mol. K), TGRIs the gas holder temperature.
The molar amount of water collected was: n iswG＝mwG/Mw
Wherein M iswThe molar mass of water is 18 g/mol.
In one embodiment of the invention, the methane gas n in the high-pressure reaction kettle in the hydrate decomposition process is calculated according to the collected molar amount of the water and the molar amount of the methane gasgN waterwAnd methane hydrate nMHMolar amount of (a):
ng＝ng0+nc-nGR
nw＝nw0+NHnc-nWR
nMH＝nMH0-nc
wherein n isg0Is the initial gas molar quantity, n, of the high-pressure reaction kettlew0Is the initial water molar weight, n, of the high-pressure reaction kettleMH0Is the initial methane hydrate molar quantity, N, of the high-pressure reaction kettleHIs the hydration number of methane hydrate, ncIs the molar amount of decomposed methane hydrate.
Calculating the volume V of water, methane gas and methane hydrate in the high-pressure reaction kettle in the decomposition process of the hydrateg、Vw、VMH:
Vg＝ngpg
Vw＝nwρw
VMH＝nMHρMH
Calculating the saturation S of the water, the methane gas and the methane hydrate in the high-pressure reaction kettle in the decomposition process of the hydrateg、Sw、SMH：
Sg＝Vg/(Vg+Vw+VMH)
Sw＝Vw/(Vg+Vw+VMH)
SMH＝VMH/(Vg+Vw+VMH)。
In an embodiment of the present invention, the method further comprises:
and dynamically adjusting the flow rate of a pipeline in front of a valve of the PID electronic controller according to the real-time quantitative gas-liquid output curve and adjusting three parameters of proportion P, integral I and differential D of the PID electronic controller in real time.
As shown in fig. 4, the invention further provides a natural gas hydrate exploitation testing apparatus for implementing any one of the above methods, which includes a high-pressure reaction unit, a controllable depressurization unit, a collection unit, a data acquisition unit and a processing unit, which are connected in sequence;
the high-pressure reaction unit comprises a high-pressure reaction kettle and is used for generating and storing a natural gas hydrate sediment reservoir;
the controllable pressure reduction unit is used for reducing the pressure at the production wellhead of the high-pressure reaction kettle to a target bottom flowing pressure through a constant pressure reduction rate by a PID electronic controller;
the data acquisition unit is used for receiving temperature signals and pressure signals in the mining process in real time and transmitting the temperature signals and the pressure signals to the processing unit;
and the processing unit is used for receiving the data of the data acquisition unit, acquiring the pressure at the exploitation wellhead of the high-pressure reaction kettle and controlling the PID electronic controller according to the data and the pressure at the exploitation wellhead of the high-pressure reaction kettle.
Specifically, the high-pressure reaction unit comprises a high-pressure reaction kettle 20, a constant-temperature water bath circulating pump 14, a top pressure sensor 7, an internal pressure sensor 4, a bottom pressure sensor 12, a temperature sensor 13 and a sand prevention device 5 arranged at an exploitation wellhead of the high-pressure reaction kettle; wherein the high-pressure reaction kettle 20 is a place for generating and storing natural gas hydrate sediments; the constant-temperature water bath circulating pump 14 is positioned at the bottom of the outer side of the high-pressure reaction kettle 20, and a constant-temperature environment is provided for the high-pressure reaction kettle 20 through the constant-temperature water bath circulating pump 14; in order to prevent hydrate formation from blocking the pressure sensors, the autoclave 20 is equipped with pressure sensors at the top, inside, and bottom for monitoring the reservoir pressure of hydrate deposits during mining. In the process of generating the hydrate, pipelines of the pressure sensors are easy to block, and therefore 3 pressure sensors are respectively arranged at the top, the inner part and the bottom of the kettle body, so that on one hand, the pressure at different positions is monitored, and meanwhile, the problem that pressure data cannot be recorded after one sensor is blocked can be prevented.
FIG. 5 is a schematic view showing the distribution of temperature sensors in the autoclave in the example of the present invention. The hydrate is decomposed into a heat absorption process in the depressurization exploitation process, due to the characteristics of heterogeneity of the distribution of methane hydrate in a reservoir, low heat conductivity coefficient of sediment and constant temperature of the outer layer of the sediment, the temperature distribution of the hydrate sediment of the high-pressure reaction kettle 20 has obvious heterogeneity characteristics, 18 temperature sensors 21 are arranged on a kettle body for effectively capturing the temperature distribution of the sediment of the high-pressure reaction kettle 20, three layers of 6 temperature sensors are annularly arranged in the kettle body, simultaneously, 4 measuring points are equidistantly distributed in the radial direction of the kettle body, and a temperature measuring system with 72 measuring points is formed for monitoring the temperature of each position of the kettle body.
A sand prevention device 5 is arranged at the mining wellhead of the high-pressure reaction kettle 20, and the sand prevention device 5 is positioned at the center of the top cover of the high-pressure reaction kettle 20 and can be connected with a vertical well and a horizontal well; meanwhile, the sand control device 5 prevents the silt from entering the pipeline.
The controllable pressure reduction unit comprises a pressure sensor 3, a manual valve 6, a pressure control valve 8, a PID electronic controller 9 and an air compressor 15, wherein the pressure sensor 3 is used for monitoring a pressure signal at a kettle body exploitation wellhead of the high-pressure reaction kettle 20 in the exploitation process, the pressure signal is a bottom hole flow pressure in an exploitation test, and the pressure signal is transmitted to the PID electronic controller 9; the manual valve 6 is positioned between the high-pressure reaction kettle 20 and the pressure control valve 8, the pressure reduction exploitation takes the opening of the manual valve 6 as a starting point, and the pressure control valve 8 reduces the pressure at the exploitation wellhead of the high-pressure reaction kettle 20 to the target bottom flowing pressure at a constant pressure reduction gradient and pressure reduction rate through a PID (proportion integration differentiation) electronic controller to realize controllable pressure reduction; wherein the air compressor 15 is used to power the PID electronic controller; the processing unit provides power parameter control for the PID electronic controller 9.
In a specific embodiment, the computer 2 is used for setting the depressurization step length of the PID electronic controller 9 and the proportion P, the integral I and the differential D of the controller, wherein the proportion P is the deviation between the pressure in the high-pressure reaction kettle 20 and the set bottom hole flow pressure which are adjusted in real time in proportion, the proportion coefficient P needs to be increased when the depressurization rate is slower than a target depressurization curve due to the difference of the hydrate decomposition rate in the experimental process according to the comparison of the depressurization curve of the pressure sensor 3 and the target depressurization curve, and otherwise, the proportion coefficient P is reduced; when the pressure in the high-pressure reaction kettle 20 is reduced to be close to the target bottom flowing pressure, only the proportion control P causes the steady-state error of the pressure reduction system because the hydrate is continuously decomposed; accumulating the steady-state error of the pressure in the high-pressure reaction kettle 20 and the target bottom hole flowing pressure by using the integral I, increasing the deviation value and further eliminating the steady-state error; the differential D is used for reducing the condition that the pressure in the autoclave is lower than the target bottom flowing pressure caused by the increase of the deviation value of the integral I, is usually used when the pressure in the autoclave 20 is close to the target bottom flowing pressure, and realizes the exploitation scheme of reducing the pressure to the stable bottom flowing pressure at a constant pressure reduction rate by the cooperation of the three.
The pressure signal is provided by a pressure sensor 3 positioned at the exploitation wellhead of the high-pressure reaction kettle 20, and a PID electronic controller 9 connected with the air compressor 15 controls the opening and closing of the pressure control valve 8 through a pneumatic valve to realize constant pressure drop rate; and changing the PID value in the computer 2 according to the experimental conditions to set the pressure drop rate, starting a control program and opening the manual valve 6 to carry out a pressure reduction exploitation experiment, so that the back pressure function is realized by the pressure control valve 8 after the controllable pressure drop process is reduced to the set bottom hole flow pressure.
Because the decomposition rate of the hydrate is nonlinear attenuation, the simple PID controller can not realize constant pressure reduction rate control, the flow rate of a pipeline in front of the PID valve is dynamically adjusted through the manual valve 6 according to a real-time quantitative gas-liquid output curve, the PID parameter of the PID electronic controller 9 is adjusted in real time, and the constant pressure reduction rate and the stable bottom hole flowing pressure in pressure reduction exploitation are realized by matching the manual valve and the PID electronic controller.
The PID electronic controller 9 is a PID (proportion-integral-derivative) controller based on a microprocessor, wherein the proportion P is the deviation of the pressure in the high-pressure reaction kettle 20 and the set bottom flow pressure which are regulated proportionally in real time; the integral I accumulates the deviation to eliminate proportional static error; the differential D is reflected as the change rate of the deviation, has the function of advance regulation, accelerates the response speed of the system and shortens the regulation time.
In one embodiment of the invention, the collecting unit is a gas-liquid production real-time quantitative unit, and comprises a gas-water separator 17, a gas collecting tank 18, an electronic scale 16, a pressure sensor 10 and a temperature sensor 11; the front and the back of the gas-water separator 17 are respectively connected with a pressure control valve 8 and a gas collecting tank 18 and are arranged on an electronic scale 16, and the liquid output in the pressure reduction exploitation process is obtained in real time through the electronic scale 16; the gas collecting tank 18 is provided with a pressure sensor 10 and a temperature sensor 11, and the real-time gas production is obtained through a processing unit; the gas collection tank 18 is provided with a blow-down valve 19.
In a specific embodiment, the data acquisition unit comprises a data acquisition instrument 1, which is used for acquiring data of each temperature sensor and each pressure sensor and providing data support for the optimization of a subsequent depressurization mining scheme; the processing unit comprises a computer 2.
In a specific embodiment of the invention, a plurality of groups of tests with different depressurization gradients and depressurization rates are carried out, and based on the test results of different depressurization rates and the same bottom hole flowing pressure, the different depressurization rates are foundThe final liquid production rate is consistent, and 8MPa/hr is selected as the optimal depressurization rate according to the mining duration and the deviation degree of the kettle pressure and temperature curve and the methane hydrate phase equilibrium curve. In one particular embodiment, the production temperature T is selectedwAt 10 ℃ and a depressurization rate vG8MPa/hr, bottom hole flowing pressure PBThe optimum depressurization gradient was analyzed for two sets of experiments at 3MPa and 5 MPa.
As shown in FIGS. 6(a) to 6(c), the experimental results are shown schematically when the bottom hole flowing pressure is 3MPa in the example of the present invention.
As shown in FIGS. 7(a) to 7(c), the experimental results are shown schematically when the bottom hole flowing pressure is 5MPa in the example of the present invention.
As can be seen from fig. 6(a) -6 (c) and 7(a) -7 (c), the control of constant pressure reduction gradient and constant pressure reduction rate and real-time quantitative information of gas-liquid production are realized according to the test method and device of the present invention. Meanwhile, when different bottom hole flowing pressures are adopted, the water production rate in the pressure reduction stage is far higher than that in the constant bottom hole flowing pressure stage; the entire production lasts 4 hours at a bottom hole flow pressure of 3MPa, and the production time is 7 hours at a bottom hole flow pressure of 5 MPa. In the whole exploitation process, according to a gas-liquid production real-time quantitative method, when the bottom hole flowing pressure is 3MPa, the water-gas ratio of a methane hydrate reservoir is 2.51, when the bottom hole flowing pressure is 5MPa, the water-gas ratio is 3.09, the exploitation time and the water-gas ratio are integrated, the bottom hole flowing pressure is 3MPa, and the depressurization rate is 8MPa/hr, so that the method is more suitable for exploiting the methane hydrate in the target hydrate reservoir.
It can be seen that the control of the constant depressurization rate and the constant bottom hole flow pressure and the quantification of the real-time gas-liquid output are the precondition of exploring the decomposition of the hydrate and the production behavior of the fluid, the invention provides a method and a device for controlling the constant depressurization rate and the constant bottom hole flow pressure and a method and a device for quantifying the real-time gas-liquid output, and an optimal bottom hole flow pressure 3MPa (depressurization gradient 11MPa) and depressurization rate 8MPa/hr mining scheme of the target reservoir stratum in the embodiment is determined based on the test result.
An embodiment of the present application further provides a control apparatus, including a processor and a storage medium for storing a computer program; wherein a processor is adapted to perform at least the method as described above when executing the computer program.
Embodiments of the present application also provide a storage medium for storing a computer program, which when executed performs at least the method described above.
Embodiments of the present application further provide a processor, where the processor executes a computer program to perform at least the method described above.
The storage medium may be implemented by any type of volatile or non-volatile storage device, or combination thereof. The nonvolatile Memory may be a Read Only Memory (ROM), a Programmable Read Only Memory (PROM), an Erasable Programmable Read-Only Memory (EPROM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), a magnetic Random Access Memory (FRAM), a Flash Memory (Flash Memory), a magnetic surface Memory, an optical Disc, or a Compact Disc Read-Only Memory (CD-ROM); the magnetic surface storage may be disk storage or tape storage. Volatile Memory can be Random Access Memory (RAM), which acts as external cache Memory. By way of illustration and not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAMEN), Synchronous linked Dynamic Random Access Memory (DRAM), and Direct Random Access Memory (DRMBER). The storage media described in connection with the embodiments of the invention are intended to comprise, without being limited to, these and any other suitable types of memory.
In the several embodiments provided in the present application, it should be understood that the disclosed system and method may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or units may be electrical, mechanical or other forms.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, all the functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be separately regarded as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.
Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the aforementioned storage medium includes: a mobile storage device, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
Alternatively, the integrated unit of the present invention may be stored in a computer-readable storage medium if it is implemented in the form of a software functional module and sold or used as a separate product. Based on such understanding, the technical solutions of the embodiments of the present invention may be essentially implemented or a part contributing to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the methods described in the embodiments of the present invention. And the aforementioned storage medium includes: a removable storage device, a ROM, a RAM, a magnetic or optical disk, or various other media that can store program code.
The methods disclosed in the several method embodiments provided in the present application may be combined arbitrarily without conflict to obtain new method embodiments.
Features disclosed in several of the product embodiments provided in the present application may be combined in any combination to yield new product embodiments without conflict.
The features disclosed in the several method or apparatus embodiments provided in the present application may be combined arbitrarily, without conflict, to arrive at new method embodiments or apparatus embodiments.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several equivalent substitutions or obvious modifications can be made without departing from the spirit of the invention, and all the properties or uses are considered to be within the scope of the invention.
Claims (10)
1. A natural gas hydrate exploitation test method is characterized by comprising the following steps:
s1: according to the pressure and the ambient temperature of a reservoir containing hydrate sediments in a target area, different pressure reduction ladders are designed based on the phase equilibrium curve of methane hydrateDegree PGDifferent decompression rates vGDownhole flow pressure to target PB；
S2: preparing methane hydrate by adopting a high-pressure reaction kettle and heating the methane hydrate from a generation temperature T in a gradient heating mode1Gradually increased to the mining temperature TwThe production temperature is the ambient temperature T of the hydrate deposit-containing reservoir in the target areaw；
S3: after the temperature of the high-pressure reaction kettle is completely balanced, controlling the depressurization step length of a PID electronic controller and the proportion P, the integral I and the differential D of the controller according to the depressurization gradient and the depressurization rate which are designed in advance, and reducing the pressure at the exploitation wellhead of the high-pressure reaction kettle to the target bottom flowing pressure according to the depressurization gradient and the depressurization rate and carrying out real-time exploitation;
s4: and respectively collecting methane gas and water produced in the depressurization exploitation process, obtaining the gas-liquid output and the saturation of three phases of methane hydrate, water and methane gas in the high-pressure reaction kettle, and determining the depressurization gradient, the depressurization rate and the target bottom hole flowing pressure for exploiting the hydrate-containing sediment reservoir stratum in the target area.
2. The gas hydrate production test method of claim 1, wherein the sediment pore water pressure P is calculated according to the depth of the hydrate-containing sediment reservoir in the target area from the sea levelw：
Pw＝Patm+ρwgh×10-6
Wherein, PatmIs atmospheric pressure in MPa; rhowIs the density of seawater, and has unit of kg/m3(ii) a g is the acceleration of gravity in m/s2(ii) a h is the depth of the seabed sediment from the sea level, and the unit is m;
calculating the environmental temperature T according to the depth of the hydrate-containing sediment reservoir of the target area from the sea levelw：
Tw＝a×hb
Wherein h is the depth of the seabed sediment from the sea level and the unit is m; a and b are empirical parameters of the reservoir temperature of the target hydrate deposit;
stabilizing the production temperature at the ambient temperature TwThen, according to a methane hydrate phase equilibrium curve, the pore water pressure P of the reservoir containing hydrate deposits in the target area is measuredwThe depressurization gradient P is designed from the methane hydrate stable regionGThe rate of depressurization vGLowering to the target bottom hole flow pressure PB。
3. The gas hydrate production test method of claim 2, wherein the production temperature is the ambient temperature T of the hydrate deposit-containing reservoir in the target zonewBefore pressure-reducing mining, temperature gradients (T)w-T1) N, dividing the methane hydrate into n steps from the generation temperature T1Gradually increasing to the mining temperature Tw；
Wherein n is a positive integer and has a value in the range of 2-5.
4. A gas hydrate production test method as claimed in claim 3, wherein the pressure reduction step of the PID electronic controller and the proportion P, integral I and derivative D of the controller are controlled to achieve the pressure reduction at the production wellhead of the autoclave to the target bottom hole stream pressure at the pressure reduction rate and the pressure reduction gradient by the following formula:
wherein, KpIs a proportionality coefficient, TiTo integrate the time constant, TdE (t) is a deviation value of the target bottom hole flow pressure and the pressure at the production wellhead of the high-pressure reaction kettle; ki＝Kp/TiIs the integral coefficient, Kd＝Kd/TdIs a differential coefficient;
Kpe (t) is a proportional term, i.e. proportionally regulating the production wellhead of the high-pressure reaction kettleA deviation of pressure from the target bottom hole flow pressure;
5. The gas hydrate production test method according to claim 4, wherein the produced water is collected using a gas-water separator, and the weight of the collected water is measured using an electronic scale; collecting the methane gas by using a gas storage tank;
the volume of methane gas collected is expressed as: vGR＝V17+V18-Vw
Wherein, V17Volume of the gas-water separator, V18Is the volume of the gas storage tank, VwIs the water yield, expressed as mwG/ρw，mwGMeasured by an electronic scale for the water production mass, pwIs the density of water, 1g/cm3；
The molar amount of methane gas collected is expressed as: n isGR＝PGRVGR/ZGR/R/TGR
Wherein, PGRFor gas tank pressure, ZGRIs the gas compression coefficient, R is the gas constant, 8.314J/(mol. K), TGRIs the temperature of the gas storage tank;
the molar amount of water collected was: n iswG=mwG/Mw
Wherein M iswThe molar mass of water is 18 g/mol.
6. The natural gas hydrate production test method according to claim 5, wherein the methane gas n in the high-pressure reaction kettle in the hydrate decomposition process is calculated according to the collected molar amount of the water and the molar amount of the methane gasgWater nw and methane hydrate nMHMolar amount of (a):
ng＝ng0+nc-nGR
nw＝nw0+NHnc-nWR
nMH＝nMH0-nc
wherein n isg0Is the initial gas molar quantity, n, of the high-pressure reaction kettlew0Is the initial molar amount of water, F, of the autoclaveMH0Is the initial methane hydrate molar quantity, N, of the high-pressure reaction kettleHIs the hydration number of methane hydrate, ncIs the molar amount of decomposed methane hydrate;
calculating the volume V of water, methane gas and methane hydrate in the high-pressure reaction kettle in the decomposition process of the hydrateg、Vw、VMH：
Vg＝ngρg
Vw＝nwρw
VMH＝nMHρMH
Calculating the saturation S of the water, the methane gas and the methane hydrate in the high-pressure reaction kettle in the decomposition process of the hydrateg、Sw、SMH：
Sg＝Vg/(Vg+Vw+VMH)
Sw＝Vw/(Vg+Vw+VMH)
SMH＝VMH/(Vg+Vw+VMH)。
7. The natural gas hydrate production test method as claimed in claim 6, further comprising:
and dynamically adjusting the flow rate of a pipeline in front of a valve of the PID electronic controller according to the real-time quantitative gas-liquid output curve and adjusting three parameters of proportion P, integral I and differential D of the PID electronic controller in real time.
8. A natural gas hydrate exploitation testing device is characterized by being used for realizing the method according to any one of claims 1 to 7, and comprising a high-pressure reaction unit, a controllable depressurization unit, a collection unit, a data acquisition unit and a processing unit which are connected in sequence;
the high-pressure reaction unit comprises a high-pressure reaction kettle and is used for generating and storing a natural gas hydrate sediment reservoir;
the controllable pressure reduction unit is used for reducing the pressure at the production wellhead of the high-pressure reaction kettle to a target bottom flowing pressure through a constant pressure reduction rate by a PID electronic controller;
the data acquisition unit is used for receiving temperature signals and pressure signals in the mining process in real time and transmitting the temperature signals and the pressure signals to the processing unit;
and the processing unit is used for receiving the data of the data acquisition unit, acquiring the pressure at the exploitation wellhead of the high-pressure reaction kettle and controlling the PID electronic controller according to the data and the pressure at the exploitation wellhead of the high-pressure reaction kettle.
9. The gas hydrate exploitation testing device according to claim 8, wherein the controllable depressurization unit comprises a pressure sensor, a manual valve, a pressure control valve, a PID electronic controller, and an air compressor;
the pressure sensor is used for monitoring a pressure signal at the exploitation wellhead of the kettle body in the exploitation process, the pressure signal is the bottom hole flowing pressure in the exploitation test, and the pressure signal is transmitted to the PID electronic controller;
the manual valve is positioned between the hydrate high-pressure reaction kettle and the pressure control valve, the pressure reduction exploitation takes the manual valve as a starting point, and the pressure control valve reduces the pressure at the exploitation wellhead of the high-pressure reaction kettle to the target bottom flowing pressure at a constant pressure reduction gradient and pressure reduction rate through a PID (proportion integration differentiation) electronic controller;
the air compressor is used to power the PID electronic controller.
10. The gas hydrate production test device according to claim 9, wherein the collection unit is a gas-liquid production real-time quantitative unit comprising a gas-water separator, a gas collection tank, an electronic scale, a pressure sensor, and a temperature sensor;
the front and the back of the gas-water separator are respectively connected with the pressure control valve and the gas collecting tank and are arranged on the electronic scale, and the liquid output in the pressure reduction exploitation process is obtained in real time through the electronic scale;
the gas collection tank is provided with the pressure sensor and the temperature sensor, and the real-time gas production is obtained through the processing unit.
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| CN115680573A (en) * | 2022-10-27 | 2023-02-03 | 大连理工大学 | Natural gas hydrate exploitation device and method based on thermodynamic driving force optimization |
| CN115680573B (en) * | 2022-10-27 | 2024-03-22 | 大连理工大学 | Natural gas hydrate exploitation device and method based on thermodynamic driving force optimization |
| CN115788385A (en) * | 2022-12-29 | 2023-03-14 | 西南石油大学 | Method for determining condensate water-gas ratio of high-temperature condensate gas reservoir |
| CN115788385B (en) * | 2022-12-29 | 2024-05-24 | 西南石油大学 | Determination method for condensate water-gas ratio of high Wen Ningxi gas reservoir |
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