Real-time evaluation device and method for core productivity of natural gas hydrate with measurable deformation

Abstract

The application discloses a natural gas hydrate core productivity real-time evaluation device and method, relates to the basic physical property measurement technical field of natural gas hydrate, and comprises a hydrate core triaxial productivity evaluation reaction kettle, a pressure maintaining system, a temperature control system, a gas-liquid collection and analysis system and a data acquisition system. The method is characterized in that: the faithful natural gas hydrate core is transferred into the hydrate core triaxial productivity evaluation reaction kettle; the pressure control system and the temperature control system are adjusted to simulate the pressure and temperature environment in the actual stratum mining process; the gas-liquid collection and analysis system is used to completely separate the gas and liquid generated by the hydrate productivity evaluation device and to perform real-time detection, the gas chromatograph is used to analyze the hydrate decomposition gas composition, the data acquisition system is used to record and analyze the decomposition rule of the hydrate in the core and the sediment deformation, and the productivity in the whole reservoir is predicted, so that guidance is provided for the mining of the hydrate in the reservoir.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of unconventional oil and gas reservoir engineering and geotechnical engineering basic physical property measurement, and particularly relates to a natural gas hydrate core productivity real-time evaluation device and method capable of measuring deformation. BACKGROUND

[0002] Natural gas hydrate, as a kind of unconventional oil and gas reservoir with huge reserves, has become a kind of new energy with great potential. The decomposition law of the exploitation process of hydrate deposits, the deformation of the deposits and the gas content are not clear, and the first step of natural gas hydrate exploitation needs to know the gas content of the reservoir, the decomposition law and the deformation of the reservoir during the seabed decomposition process to real-time characterize the exploitation process and optimize the exploitation scheme.

[0003] Due to the great difficulty and high cost of offshore natural gas hydrate coring, it is difficult to transfer the faithful core sample to the onshore laboratory, and the cycle is long, which leads to the distortion of hydrate. It is very important to quickly evaluate the productivity of hydrate reservoirs on the ship. The existing device mainly simulates the productivity evaluation of hydrate core in the onshore laboratory. The difference between the simulated core properties and the actual hydrate core is large, and the real decomposition law cannot be reflected. Foreign technology blockade affects the progress of hydrate exploitation in China, and China still does not have a device for on-site natural gas hydrate core productivity evaluation on the ship, which seriously affects the exploitation process of hydrate reservoirs.

[0004] A non-in-situ core gas and liquid production measuring device (CN216560578U) can measure the gas and water production of hydrate decomposition under different temperature and pressure conditions. A triaxial experimental device (CN110441153A) can detect the deformation of the hydrate core and test the saturation of the core through an acoustic testing device. Most of the current devices are for testing the gas and water production, deformation and saturation of non-in-situ hydrate cores. The difference between the properties of non-in-situ core and in-situ core is large, and the real decomposition law cannot be reflected. SUMMARY

[0005] In order to overcome the above problems, the present application provides a natural gas hydrate core productivity real-time evaluation device and method capable of measuring deformation, which has small volume, low cost and simple operation, is suitable for various analysis equipment, can quickly evaluate the productivity of hydrate reservoirs and the deformation in the decomposition process of the reservoir, uses definition method to test the decomposition law of hydrate in the core sample, quickly and accurately evaluates the exploitability of the reservoir, and realizes the test of gas and water production and saturation of in-situ hydrate core with measurable deformation.

[0006] The present application is realized at least by one of the following technical solutions.

[0007] A natural gas hydrate core productivity real-time evaluation device capable of measuring deformation, a hydrate core triaxial productivity evaluation reactor, a pressure control system, a temperature control system, a gas-liquid collection and analysis system and a data acquisition system;

[0008] The hydrate core triaxial productivity evaluation reactor comprises a decomposition reactor body, a clamp, a butt joint connected with the decomposition reactor body and a hydraulic cylinder; the decomposition reactor body is internally provided with an elastic metal film, and the hydraulic cylinder is connected with the decomposition reactor body through the clamp; the hydraulic cylinder comprises an axial piston and a core plug; the top of the axial piston is connected with the core plug; a fluid outlet is formed in the axial piston;

[0009] The pressure control system comprises an axial pressure plunger pump, a confining pressure plunger pump, a pore pressure plunger pump, a pre-cooling pipeline and a vacuum pump; the axial pressure plunger pump is connected with an upper axial pressure injection hole and a lower axial pressure injection hole of the hydraulic cylinder through a first electromagnetic valve and a second electromagnetic valve respectively; the pore pressure plunger pump is connected with the pre-cooling pipeline arranged in a water bath box; the confining pressure plunger pump is connected with a confining pressure injection hole of the decomposition reactor body through a second three-way valve and a third electromagnetic valve; and the vacuum pump is connected with a gas collection tank through a ninth electromagnetic valve;

[0010] The temperature control system comprises a refrigerated water bath circulator, the water bath box and an outer circulating water bath jacket; the inlet and outlet of the water bath box are connected with the refrigerated water bath circulator; the bottom and top of the outer circulating water bath jacket are provided with an inlet and an outlet connected with the refrigerated water bath circulator;

[0011] The gas-liquid collection and analysis system comprises a third three-way valve, a filter, a back pressure valve, a gas-liquid separator, a gas collection tank, a liquid collection tank, a gas chromatograph and a drain valve; the gas collection tank is connected to the gas-liquid separator through a seventh electromagnetic valve; the gas-liquid separator is sequentially connected to the fluid outlet of the axial piston through the back pressure valve, a sixth electromagnetic valve, the filter and the third three-way valve; the liquid collection tank is connected to the gas-liquid separator through the drain valve; and the gas chromatograph is connected to the gas collection tank through a tenth electromagnetic valve;

[0012] The data acquisition system comprises a computer, a liquid flow meter, a first temperature sensor, a second temperature sensor, a third temperature sensor, a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor, a liquid level meter, the liquid flow meter is connected between a four-way valve and a fourth electromagnetic valve, the first temperature sensor and the second pressure sensor are connected to the four-way valve at the outlet of the pre-cooling pipeline, the second temperature sensor is connected to the decomposition kettle, the first pressure sensor is connected between the confining pressure piston pump and the third electromagnetic valve, the third pressure sensor is connected to the third three-way valve, the third temperature sensor and the fourth pressure sensor are connected to the gas-liquid separator, the liquid level meter is connected to the liquid collection tank, and the output ends of all the sensors are connected to the computer.

[0013] Further, the butt joint is provided with a ball valve, and the ball valve is installed in the butt joint by bolts.

[0014] Further, the hydrate core triaxial productivity evaluation reaction kettle is wrapped with rock wool pipe thermal insulation material.

[0015] Further, the core plug is provided with a groove, and the elastic metal film is fixed to the butt joint and the groove of the core plug respectively.

[0016] Further, the pre-cooling pipeline is connected to the elastic metal film.

[0017] Further, the confining pressure piston pump and the axial piston pump are pressure tracking pumps.

[0018] Further, the core plug is provided with a sintered sheet.

[0019] Further, a displacement sensor is installed on the top of the axial piston.

[0020] Further, a plurality of electromagnetic valves are further included, the plurality of electromagnetic valves including a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve, a fourth electromagnetic valve, a fifth electromagnetic valve, a sixth electromagnetic valve, a seventh electromagnetic valve, an eighth electromagnetic valve, a ninth electromagnetic valve, and a tenth electromagnetic valve; the first electromagnetic valve is located between an injection hole on the shaft of the hydraulic cylinder and the first three-way valve; the second electromagnetic valve is located between an injection hole below the shaft of the hydraulic cylinder and the first three-way valve; the third electromagnetic valve is located between the confining pressure plunger pump and the confining pressure injection hole of the decomposition kettle body; the fourth electromagnetic valve is located between the four-way valve and the injection hole of the elastic metal film; the fifth electromagnetic valve is located on the confining pressure pressure relief port of the decomposition kettle body; the sixth electromagnetic valve is located between the filter and the back pressure valve; the seventh electromagnetic valve is located between the gas-liquid separator and the gas collection tank; the eighth electromagnetic valve is located on the emptying pipeline of the gas collection tank; the ninth electromagnetic valve is located between the vacuum pump and the gas collection tank; and the tenth electromagnetic valve is located between the gas chromatograph and the gas collection tank; and the electromagnetic valves are connected with the electromagnetic control module.

[0021] The method for realizing the real-time evaluation device for the production capacity of a natural gas hydrate core with measurable deformation is applied to a process of evaluating the in-situ production capacity of a hydrate core in fidelity, and includes the following steps:

[0022] Step 1: After checking the air tightness of the device, the inside of the hydrate core triaxial production capacity evaluation reactor is cleaned with deionized water, the elastic metal film is fixed to the ball valve base and the groove of the core plug respectively, the elastic metal film is surrounded to form a cylindrical space, and then the refrigerated water bath circulator is turned on to stabilize the temperature of the hydrate core triaxial production capacity evaluation reactor to 4-6℃;

[0023] Step 2: After connecting the hydrate core triaxial production capacity evaluation reactor and the storage chamber with the hydrate core, the third electromagnetic valve and the fourth electromagnetic valve are opened, the confining pressure plunger pump is used to inject and the pore pressure plunger pump is used to maintain the pressure difference to inject liquid, the pressure on both ends is balanced, the ball valve is turned to transfer the 20 cm core sample into the elastic metal film in the low-temperature hydrate core triaxial production capacity evaluation reactor, the ball valve is closed, and the hydrate core triaxial production capacity evaluation reactor is transferred;

[0024] Step 3: The hydrate core triaxial production capacity evaluation reactor, the filter, the back pressure valve, the gas-liquid separator, the gas collection tank, the liquid collection tank, and the gas chromatograph are connected, the eighth electromagnetic valve is opened, and the vacuum pump is used to vacuum the entire gas-liquid collection and analysis system;

[0025] Step 4, the rate of pressure change of the confining plunger pump and the axial plunger pump is controlled by the computer, the back pressure valve is adjusted to control the pressure change in the hydrate core triaxial productivity evaluation reactor, the drainage valve and the seventh electromagnetic valve are opened, the triaxial decomposition productivity evaluation of the hydrate core is carried out, the gas and liquid production during the process is collected, and the composition of the decomposition gas is analyzed in a timed manner during the gas production by opening the tenth electromagnetic valve;

[0026] Step 5, the data of the temperature, pressure, displacement sensor and liquid level meter are recorded, when the second temperature sensor, the second pressure sensor, the third pressure sensor, the third temperature sensor and the fourth temperature sensor are raised until stable, the experiment is stopped, and all the sensor data during the decomposition process are recorded;

[0027] Step 6, the obtained data is processed and analyzed by the computer to obtain the decomposition rule of the natural gas hydrate.

[0028] Compared with the prior art, the hydrate core productivity evaluation reactor has the advantages that:

[0029] Compared with the prior art, the hydrate core productivity evaluation reactor has the advantages that

[0030] 1, the design pressure of the hydrate core productivity evaluation reactor is 0-35MPa, the design temperature is-10-100 DEG C, the adapter of the device can be connected to different analysis systems, a plurality of different specifications of cores can be evaluated, the ball valve can play a blocking role, and the pressure transfer of the hydrate can be carried out

[0031] 2, the hole plunger pump in the pressure control system of the device can provide an in-situ high-pressure environment of the hydrate, and ensure that the pressure of the sample is stable during the transfer process

[0032] 3, the axial piston and the confining plunger pump of the device can simulate the actual in-situ pressure environment of the seabed, the productivity of the hydrate can be evaluated under the in-situ triaxial of the faithful hydrate core sample, and the decomposition rule of the hydrate decomposition and the deformation of the reservoir can be obtained.

[0033] 4, the data acquisition system of the device can record the data in the process in real time, and the automatic productivity evaluation, automatic data processing and analysis and automatic productivity evaluation can be realized by cooperating with the special software.

[0034] 5, the gas-liquid collection and analysis system of the device can adjust the decomposition pressure of the in-situ hydrate core at a constant pressure and a constant speed, can simulate the pressure regulation in the actual mining process, the drainage valve is installed at the lower end of the gas-liquid separator, can completely separate the gas and water, and accurately measure the gas and liquid production during the decomposition process. BRIEF DESCRIPTION OF DRAWINGS

[0035] Fig. 1is a schematic diagram of a real-time evaluation device for measuring the deformation of a natural gas hydrate core;

[0036] Fig. 2 is a sectional view of a hydrate core triaxial productivity evaluation reactor kettle of the embodiment;

[0037] Fig. 3 is a sectional view of a hydraulic cylinder of the embodiment;

[0038] The various components in the figure are as follows:

[0039] Axial pressure plunger pump 1, confining pressure plunger pump 2, first three-way valve 3, second three-way valve 4, refrigerated water bath circulator 5, pore pressure plunger pump 6, water bath box 7, pre-cooling pipeline 8, accumulator filter 9, four-way valve 10, decomposition kettle body 11, confining pressure injection hole 12, clamp 13, axial pressure upper injection hole 14, axial pressure lower injection hole 15, hydraulic cylinder 16, axial piston 17, fluid outlet 18, core plug 19, sintered sheet 20, elastic metal film 21, temperature sensor mounting hole 22, outer circulating water bath jacket 23, confining pressure relief port 24, ball valve 25, rock wool pipe insulation material 26, butt joint 27, vacuum pump 28, third three-way valve 29, filter 30, back pressure valve 31, gas-liquid separator 32, gas collection tank 33, drain valve 34, liquid collection tank 35, gas chromatograph 36, computer 37, first pressure sensor 38, first temperature sensor 39, flow meter 40, second pressure sensor 41, displacement sensor 42, second temperature sensor 43, third pressure sensor 44, third temperature sensor 45, fourth pressure sensor 46, liquid level meter 47, first solenoid valve 48, second solenoid valve 49, third solenoid valve 50, fourth solenoid valve 51, fifth solenoid valve 52, sixth solenoid valve 53, seventh solenoid valve 54, eighth solenoid valve 55, ninth solenoid valve 56, tenth solenoid valve 57. DETAILED DESCRIPTION

[0040] The present application will be described in detail below with specific embodiments. The specific embodiments of the present application are described in detail below in combination with the technical solutions and the drawings.

[0041] The present example provides a real-time evaluation device for measuring the deformation of a natural gas hydrate core, as shown in Figs. 1-3 including a hydrate core triaxial productivity evaluation reactor kettle, a pressure maintenance system, a temperature control system, a gas-liquid collection and analysis system, a data acquisition system, and a plurality of solenoid valves.

[0042] The hydrate core triaxial productivity evaluation reaction kettle comprises a decomposition kettle body 11, a clamp 13, a butt joint 27 connected with the decomposition kettle body 11 and a hydraulic cylinder 16; the decomposition kettle body 11 is internally provided with an elastic metal film 21; the hydraulic cylinder 16 is connected with the decomposition kettle body 11 through the clamp 13; the hydraulic cylinder 16 comprises an axial piston 17 and a core plug 19; the top of the axial piston 17 is connected with the core plug 19; the core plug 19 is provided with a sintered sheet 20 below; the decomposition kettle body 11 is provided with a temperature sensor mounting hole 22 on the side; the butt joint 27 is internally provided with a ball valve 25 which is mounted in the butt joint 27 through bolts.

[0043] The core plug 19 is internally provided with a groove, and the elastic metal film 21 is fixed to the butt joint 27 and the groove in the core plug 19 respectively.

[0044] The axial piston 17 is provided with a fluid outlet 18; and a displacement sensor 42 is mounted on the top of the axial piston 17.

[0045] The pressure control system comprises an axial plunger pump 1, a confining pressure plunger pump 2, a first three-way valve 3, a second three-way valve 4, a pore pressure plunger pump 6, a pre-cooling pipeline 8 and a vacuum pump 28; the axial plunger pump 1 is connected with the axial pressure upper injection hole 14 and the axial pressure lower injection hole 15 of the hydraulic cylinder 16 through the first three-way valve 3, a first electromagnetic valve 48 or a second electromagnetic valve 50 respectively; the pore pressure plunger pump 6 is connected with the pre-cooling pipeline 8 arranged in a water bath box 7; the axial pressure upper injection hole 14 and the axial pressure lower injection hole 15 are located at the lower part and the upper part of the hydraulic cylinder 16; the confining pressure plunger pump 2 is connected with the confining pressure injection hole 12 of the decomposition kettle body 11 through the second three-way valve 4 and a third electromagnetic valve 50; the vacuum pump 28 is connected with a gas collection tank 33 through a ninth electromagnetic valve 56.

[0046] The temperature control system comprises a refrigerated water bath circulator 5, a water bath box 7, an outer circulating water bath jacket 23 and rock wool pipe thermal insulation material 26; the water bath box 7 is provided with liquid inlets and outlets on the bottom and the top and is connected with the refrigerated water bath circulator 5; the outer circulating water bath jacket 23 is provided with liquid inlets and outlets on the bottom and the top and is connected with the refrigerated water bath circulator 5; the rock wool pipe thermal insulation material 26 is wrapped outside the hydrate core triaxial productivity evaluation reaction kettle; the circulating water bath 5 can change the temperature of the circulating refrigerant.

[0047] The gas-liquid collection and analysis system comprises a third three-way valve 29, a filter 30, a back pressure valve 31, a gas-liquid separator 32, a gas collection tank 33, a liquid collection tank 35, a gas chromatograph 36 and a drain valve 34; the gas collection tank is connected to the gas-liquid separator 32 through a seventh electromagnetic valve 54; the gas-liquid separator is connected to the fluid outlet 18 on the axial piston 17 through the back pressure valve 31, a sixth electromagnetic valve 53, the filter 30 and the third three-way valve 29; the liquid collection tank 35 is connected to the gas-liquid separator 32 through the drain valve 34; the gas chromatograph 36 is connected to the gas collection tank 33 through a tenth electromagnetic valve 57.

[0048] The data acquisition system comprises a computer 37, a liquid flow meter 40, a first temperature sensor 39, a second temperature sensor 43, a third temperature sensor 45, a first pressure sensor 38, a second pressure sensor 41, a third pressure sensor 44, a fourth pressure sensor 46 and a liquid level meter 47; the liquid flow meter 40 is connected between the four-way valve 10 and a fourth electromagnetic valve 51; the first temperature sensor 39 and the second pressure sensor 41 are connected to the four-way valve 10 at the outlet of the pre-cooling pipeline, and an accumulator filter 9 is arranged between the four-way valve 10 at the outlet of the pre-cooling pipeline and the pre-cooling pipeline 8; the second temperature sensor is connected to the decomposition kettle body 11; the first pressure sensor 38 is connected between the confining pressure plunger pump 2 and a third electromagnetic valve 50; the third pressure sensor 44 is connected to the third three-way valve 29; the third temperature sensor 45 and the fourth pressure sensor 46 are connected to the gas-liquid separator 32; the liquid level meter 47 is connected to the liquid collection tank 35; and all the sensor signal output ends are connected to the computer 37.

[0049] The electromagnetic valves comprise a first electromagnetic valve 48, a second electromagnetic valve 49, a third electromagnetic valve 50, a fourth electromagnetic valve 51, a fifth electromagnetic valve 52, a sixth electromagnetic valve 53, a seventh electromagnetic valve 54, an eighth electromagnetic valve 55, a ninth electromagnetic valve 56 and a tenth electromagnetic valve 57.

[0050] The first solenoid valve 48 is located between the shaft pressure injection hole 14 of the hydraulic cylinder 16 and the first three-way valve 3, the second solenoid valve 49 is located between the shaft pressure injection hole 15 of the hydraulic cylinder 16 and the first three-way valve 3, the third solenoid valve 50 is located between the confining pressure plunger pump 2 and the confining pressure injection hole 12 of the decomposing kettle body 11, the fourth solenoid valve 51 is located between the four-way valve 10 and the injection hole of the elastic metal film, the fifth solenoid valve 52 is located on the confining pressure relief port 24 of the decomposing kettle body 11, the sixth solenoid valve 53 is located between the filter 30 and the back pressure valve 31, the seventh solenoid valve 54 is located between the gas-liquid separator 32 and the gas collection tank 33, the eighth solenoid valve 55 is located on the emptying pipeline of the gas collection tank 33, the ninth solenoid valve 56 is located between the vacuum pump 28 and the gas collection tank 33, and the tenth solenoid valve 57 is located between the gas chromatograph 36 and the gas collection tank 33. The solenoid valves are connected with the electromagnetic control module.

[0051] As an embodiment, the elastic metal film 21 is stretchable; and the pre-cooling pipeline 8 is connected to the elastic metal film 21 in the decomposing kettle body.

[0052] As an embodiment, the confining pressure plunger pump 2 and the shaft pressure plunger pump 1 are pressure tracking pumps. The drain valve 31 is a drain valve without exhausting. The first temperature sensor 39, the second temperature sensor 43, the third temperature sensor 45, the first pressure sensor 38, the second pressure sensor 41, the third pressure sensor 44, the fourth pressure sensor 46, the flow meter 40 and the liquid level meter 47 are all real-time meters.

[0053] Embodiment 2

[0054] A method for real-time evaluation of in-situ productivity of a natural gas hydrate core by using the device, comprising the following steps:

[0055] Step 1, after checking the air tightness of the device, using deionized water to clean the inside of the hydrate core productivity evaluation reactor, fixing the elastic metal film to the butt joint and the groove of the core plug respectively, surrounding the elastic metal film to form a cylindrical space, and then opening the refrigerated water bath circulator to stabilize the temperature of the hydrate core productivity evaluation reactor to 4-6℃;

[0056] Step 2, after connecting the hydrate core triaxial productivity evaluation reactor and the storage chamber with the hydrate core, opening the third solenoid valve and the fourth solenoid valve, using the confining pressure plunger pump to inject and the shaft pressure plunger pump to maintain a certain pressure difference to balance the pressure on both ends, rotating the ball valve to transfer the 20cm core sample to the elastic metal film in the low-temperature hydrate core triaxial productivity evaluation reactor, closing the ball valve, and transferring the hydrate core triaxial productivity evaluation reactor.

[0057] Step 3, connect the hydrate core productivity evaluation reactor, filter, back pressure valve, gas-liquid separation tank, liquid collection tank, gas collection tank and gas chromatograph, open the eighth solenoid valve, use the vacuum pump to vacuum the whole gas-liquid collection and analysis system.

[0058] Step 4, adjust the pressure change in the hydrate core triaxial productivity evaluation reactor by controlling the rate of pressure change of the confining pressure piston pump and the axial pressure piston pump through the computer, open the drain valve and the seventh solenoid valve, carry out the triaxial decomposition productivity evaluation of the hydrate core, collect the gas and liquid production during the process, and open the tenth solenoid valve to analyze the composition of the decomposition gas in a timely manner during the gas production.

[0059] Step 5, record the data of temperature, pressure, displacement sensor and liquid level meter, stop the experiment when the temperature of the second temperature sensor, the second pressure sensor, the third pressure sensor, the third temperature sensor and the fourth temperature sensor rises until stable, and record all the sensor data during the decomposition process.

[0060] Step 6, process and analyze the data obtained by the data acquisition system through the data processing software in the computer to obtain the decomposition law of natural gas hydrate.

[0061] Example 3

[0062] The present example provides a method for real-time evaluation of the in-situ productivity of a natural gas hydrate core using the device, comprising the following steps:

[0063] Step 1, after checking the air tightness of the device, use deionized water to clean the inside of the hydrate core productivity evaluation reactor, fix the elastic metal film to the butt joint and the groove of the core plug respectively, enclose the elastic metal film into a cylindrical space, and then open the refrigerated water bath circulator to stabilize the temperature of the hydrate core productivity evaluation reactor to 4-6℃;

[0064] Step 2, after connecting the hydrate core triaxial productivity evaluation reactor and the storage chamber with the hydrate core, open the third solenoid valve and the fourth solenoid valve, use the confining pressure piston pump to inject and the pore pressure piston pump to maintain a certain pressure difference to inject liquid, balance the pressure on both ends to 10MPa, rotate the ball valve to transfer the 10cm core sample into the elastic metal film in the low-temperature hydrate core triaxial productivity evaluation reactor, close the ball valve, and transfer the hydrate core triaxial productivity evaluation reactor.

[0065] Step 3, after connecting the hydrate core productivity evaluation reactor, filter, back pressure valve, gas-liquid separation tank, liquid collection tank, gas collection tank and gas chromatograph, open the eighth solenoid valve, use the vacuum pump to vacuum the whole gas-liquid collection and analysis system for 30min.

[0066] Step 4, the pressure of the confining pressure piston pump and the axial pressure piston pump is adjusted to 10 MPa by the computer, the brine solution at 25℃ is injected at 10 ml / min by the pore pressure piston pump, the pressure of the back pressure valve is adjusted to 0.1 MPa / min, the water valve and the seventh electromagnetic valve are opened, the triaxial dissociation productivity evaluation of the hydrate core is carried out, the gas and liquid production during the process is collected, and the tenth electromagnetic valve is opened to analyze the composition of the dissociation gas in a timing manner during the gas production.

[0067] Step 5, the data of the temperature, pressure, displacement sensor and liquid level meter are recorded, when the temperature of the second temperature sensor, the second pressure sensor, the third pressure sensor, the third temperature sensor and the fourth temperature sensor rises until stable, the experiment is stopped, and all the sensor data during the dissociation process is recorded.

[0068] Step 6, the data obtained by the data acquisition system is processed and analyzed by the data processing software in the computer, and the dissociation law of the natural gas hydrate is obtained.

[0069] The above examples are only for illustrating the technical concept and characteristics of the present application, the purpose is to enable the person skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A device for real-time evaluation of gas hydrate core deliverability with measurable deformation, characterized in that: The hydration core triaxial productivity evaluation reactor kettle comprises a decomposition kettle body (11), a clamp (13), a butt joint (27) connected with the decomposition kettle body (11), and a hydraulic cylinder (16); the decomposition kettle body (11) is internally provided with an elastic metal film (21), and the hydraulic cylinder (16) is connected with the decomposition kettle body (11) through the clamp (13); the hydraulic cylinder (16) comprises an axial piston (17) and a core plug (19); the top of the axial piston (17) is connected with the core plug (19); a fluid outlet (18) is formed in the axial piston (17); the core plug (19) is internally provided with a groove, and the elastic metal film (21) is fixed to the butt joint (27) and the groove in the core plug (19) respectively; the butt joint (27) is internally provided with a ball valve (25), and the ball valve (25) is installed in the butt joint (27) through bolts; the pressure control system comprises an axial pressure plunger pump (1), a confining pressure plunger pump (2), a pore pressure plunger pump (6), a pre-cooling pipeline (8), and a vacuum pump (28); the axial pressure plunger pump (1) is connected with an axial pressure upper injection hole (14) and an axial pressure lower injection hole (15) of the hydraulic cylinder (16) through a first electromagnetic valve (48) and a second electromagnetic valve respectively; the pore pressure plunger pump (6) is connected with the pre-cooling pipeline (8) arranged in a water bath box (7); the confining pressure plunger pump (2) is connected with a confining pressure injection hole (12) of the decomposition kettle body (11) through a second three-way valve (4) and a third electromagnetic valve (50); the vacuum pump (28) is connected with a gas collection tank (33) through a ninth electromagnetic valve (56); the temperature control system comprises a refrigerated water bath circulator (5), the water bath box (7), and an outer circulating water bath jacket (23); the inlet and outlet of the water bath box (7) are connected with the refrigerated water bath circulator (5); the bottom and top of the outer circulating water bath jacket (23) are provided with an inlet and an outlet connected with the refrigerated water bath circulator (5); the gas-liquid collection and analysis system comprises a third three-way valve (29), a filter (30), a back pressure valve (31), a gas-liquid separator (32), the gas collection tank (33), a liquid collection tank (35), a gas chromatograph (36), and a drain valve (34); the gas collection tank (33) is connected to the gas-liquid separator (32) through a seventh electromagnetic valve (54); the gas-liquid separator (32) is sequentially connected to the fluid outlet (18) of the axial piston (17) through the back pressure valve (31), a sixth electromagnetic valve (53), the filter (30), and the third three-way valve (29); the liquid collection tank (35) is connected to the gas-liquid separator (32) through the drain valve (34); the gas chromatograph (36) is connected to the gas collection tank (33) through a tenth electromagnetic valve (57). ​ ​ ​ ​ ​ ​ The data acquisition system comprises a computer (37), a liquid flow meter (40), a first temperature sensor (39), a second temperature sensor (43), a third temperature sensor (45), a first pressure sensor (38), a second pressure sensor (41), a third pressure sensor (44), a fourth pressure sensor (46), and a liquid level meter (47); the liquid flow meter (40) is connected between a four-way valve (10) and a fourth electromagnetic valve (51); the first temperature sensor (39) and the second pressure sensor (41) are connected to the four-way valve (10) at the outlet of a pre-cooling pipeline (8); the second temperature sensor (43) is connected to a decomposition kettle body (11); the first pressure sensor (38) is connected between a confining pressure piston pump (2) and a third electromagnetic valve (50); the third pressure sensor (44) is connected to a third three-way valve (29); the third temperature sensor (45) and the fourth pressure sensor (46) are connected to a gas-liquid separator (32); the liquid level meter (47) is connected to a liquid collection tank (35); and the signal output ends of all the sensors are connected to the computer (37).

2. The apparatus for real-time evaluation of gas hydrate core deliverability with measurable deformation according to claim 1, wherein, An outer wrapping rock wool pipe thermal insulation material (26) is provided on the hydrate core triaxial productivity evaluation reaction kettle.

3. The apparatus of claim 1, wherein: The pre-cooling pipeline (8) is connected to an elastic metal film (21).

4. The apparatus of claim 1, wherein: The confining pressure piston pump (2) and the axial pressure piston pump (1) are both pressure tracking pumps.

5. The apparatus of claim 1, wherein: A sintered sheet (20) is arranged below the core plug (19).

6. The apparatus of claim 1, wherein: A displacement sensor (42) is mounted on the top of the axial piston (17).

7. The apparatus of claim 6, wherein: Further comprising several electromagnetic valves, several electromagnetic valves include first electromagnetic valve (48), second electromagnetic valve (49), third electromagnetic valve (50), fourth electromagnetic valve (51), fifth electromagnetic valve (52), sixth electromagnetic valve (53), seventh electromagnetic valve (54); Eighth electromagnetic valve (55), ninth electromagnetic valve (56), tenth electromagnetic valve (57), the first electromagnetic valve (48) is located between the injection hole (14) of the hydraulic cylinder (16) and the first three-way valve (3) on the shaft pressure, the second electromagnetic valve (49) is located between the injection hole (15) of the hydraulic cylinder (16) and the first three-way valve (3) on the shaft pressure, the third electromagnetic valve (50) is located between the confining pressure plunger pump (2) and the confining pressure injection hole (12) of the decomposition kettle body (11), the fourth electromagnetic valve (51) is located between the four-way valve (10) and the injection hole of the elastic metal film, the fifth electromagnetic valve (52) is located on the confining pressure relief port (24) of the decomposition kettle body (11), the sixth electromagnetic valve (53) is located between the filter (30) and the back pressure valve (31), the seventh electromagnetic valve (54) is located between the gas-liquid separator (32) and the gas collection tank (33), the eighth electromagnetic valve (55) is located on the emptying pipeline of the gas collection tank (33), the ninth electromagnetic valve (56) is located between the vacuum pump (28) and the gas collection tank (33), the tenth electromagnetic valve (57) is located between the gas chromatograph (36) and the gas collection tank (33), the electromagnetic valves are connected with the electromagnetic control module.

8. The method of realizing the real-time evaluation device of the measurable deformation of the natural gas hydrate core productivity according to claim 7, characterized in that, Applied to the process of evaluating the in-situ productivity of the hydrate core, including the following steps: Step 1, after checking the air tightness of the device, use deionized water to clean the inside of the hydrate core triaxial productivity evaluation reactor, fix the elastic metal film (21) on the ball valve base and the groove of the core plug respectively, surround the elastic metal film (21) to form a cylindrical space, and then open the refrigerated water bath circulator to make the temperature of the hydrate core triaxial productivity evaluation reactor stable at 4-6℃; Step 2, after connecting the hydrate core triaxial productivity evaluation reactor and the storage chamber with the hydrate core, open the third electromagnetic valve (50) and the fourth electromagnetic valve (51), use the confining pressure plunger pump (2) to inject and the pore pressure plunger pump (6) to maintain the pressure difference to balance the pressure on both ends, rotate the ball valve (25) to transfer the 20 cm core sample into the elastic metal film in the low-temperature hydrate core triaxial productivity evaluation reactor, close the ball valve (25), and transfer the hydrate core triaxial productivity evaluation reactor; Step 3, connect the hydrate core triaxial productivity evaluation reactor, filter (30), back pressure valve (31), gas-liquid separator (32), gas collection tank (33), liquid collection tank (35), and gas chromatograph (36), open the eighth electromagnetic valve (55), and use the vacuum pump to vacuum the whole gas-liquid collection and analysis system; Step 4, the rate of pressure change of confining pressure piston pump (2) and axial pressure piston pump (1) is controlled by computer (37), the pressure change in the hydrate core triaxial productivity evaluation reactor is adjusted by back pressure valve (31), the drainage valve (34) and the seventh solenoid valve (54) are opened, the triaxial decomposition productivity evaluation of hydrate core is carried out, the gas and liquid production during the process is collected, and the composition of the decomposition gas is analyzed at regular time intervals during the gas production by opening the tenth solenoid valve (57); Step 5, the data of temperature, pressure, displacement sensor and liquid level meter are recorded, when the second temperature sensor (43), the second pressure sensor (41), the third pressure sensor (44), the third temperature sensor (45) and the fourth temperature sensor (46) rise until stable, the experiment is stopped, and all the sensor data during the decomposition process are recorded; Step 6, the obtained data is processed and analyzed by computer (37), and the decomposition law of natural gas hydrate is obtained.

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