A real-time monitoring rock core displacement process test system based on optical fiber sensing and a working method thereof

Abstract

The application discloses a real-time monitoring rock core displacement process test system based on optical fiber sensing and a working method thereof, and belongs to the field of oil and gas resource development and greenhouse gas storage. The test system comprises a visual rock core displacement device, an optical fiber sensing monitoring system, a gas injection system, a liquid injection system, a constant-temperature confining pressure control system, a separation and collection system and a data acquisition and analysis device. The fluid migration interface position, the rock core strain distribution field and the temperature field and the like in the rock core displacement process can be monitored in real time through optical fiber sensing, and a visual calibration method is provided. The application is used for exploring the migration characteristics and mechanism of the fluid in the rock core in the displacement process, capturing the displacement wetting interface, and providing reliable test basis and theoretical analysis for real reservoir gas storage.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas resource development and greenhouse gas storage, and particularly relates to a real-time monitoring rock core displacement process visualization test system and method based on optical fiber sensing. BACKGROUND

[0002] Rock core displacement experiment generally refers to that under certain temperature and pressure, a single-phase or multi-phase mixed fluid is artificially made to pass through a rock core at a certain flow rate, and a part of the original fluid in the rock core is displaced. The displacement test for the rock core can restore the formation basic characteristics such as porosity, permeability and sensitivity of the formation where the rock core is sampled, and has important significance in the fields of oil and gas resource development and greenhouse gas storage.

[0003] The visualized rock core displacement test system generally uses X-Ray CT to shoot the rock core in the displacement process, and obtains important information such as the migration front and migration state of the displacement phase fluid in the rock core. However, due to the limitation of the CT detection technology, the internal flow data of the rock core cannot be obtained in real time. The conventional micro-focus CT technology platform also cannot bear the weight of the large-size rock core and the high-pressure maintaining device attached thereto, and the small-size rock core shows strong scale and marginal effect in the experiment, and cannot accurately restore the migration state of the fluid in the formation. Moreover, the large visualized instrument such as micro-focus CT is expensive and complicated to operate, and has high requirements for the installation site and the operator. SUMMARY

[0004] In order to overcome the above-mentioned defects of the prior art, the present application proposes a real-time monitoring system and visualization calibration method based on optical fiber sensing for the conventional rock core displacement test system, so as to provide reliable real-time monitoring and visualization while performing the conventional rock core displacement experiment, and more accurately observe and master the migration characteristics of the fluid in the rock core.

[0005] The technical scheme of the present application: a real-time monitoring rock core displacement process test system based on optical fiber sensing, which comprises a visualized rock core displacement device, an optical fiber monitoring system, a constant-temperature confining pressure loading system, a gas injection-liquid injection switching system, a back pressure control and collection system, and a data acquisition and analysis device.

[0006] In the visualized rock core displacement optical fiber monitoring device, the rock core is fixedly placed in the rock core holder with a single-mode optical fiber wound thereon, so as to ensure the sealing of the rock core injection and outflow interfaces; the piston container and the circulating pump are connected with the confining pressure cavity of the rock core holder, so as to maintain the constant-temperature confining pressure; the rock core holder is arranged inside the micro-focus CT, so as to obtain the rock core internal displacement process image in the corresponding period and calibrate the monitoring result of the optical fiber system;

[0007] The single-mode optical fiber in the optical fiber monitoring system is spirally wound on the core and fixed in the core holder to detect the strain and temperature change of each sensing unit on the core in the injection process; the demodulator is connected with the single-mode optical fiber and the data acquisition computer to analyze and process the collected signals and display the excitation intensity corresponding to different positions on the optical fiber on the computer in real time;

[0008] In the constant-temperature confining pressure loading system, the second water supply valve controls the second solution tank to inject liquid to the second compression pump, and then through the second water inlet valve, the liquid is injected to the upper cover of the piston container to control the liquid in the inner cavity and the confining pressure of the core holder to the experimental working condition; the piston container and the circulating pump are immersed in the water bath and connected with the first water bath to control the liquid temperature in the piston container to be constant; the circulating pump is connected with the piston container and the confining pressure cavity of the core holder, and through controlling the circulating flow of the liquid in the confining pressure cavity, the temperature in the core holder is kept uniform and constant under the condition of ensuring the confining pressure.

[0009] In the gas-liquid injection switching system, the first water supply valve controls the first solution tank to inject deionized water to the first compression pump, and then through the first water inlet valve and the inlet valve, the deionized water is injected to the core at a set temperature and pressure to saturate the core;

[0010] The gas supply valve controls the high-pressure gas cylinder to inject gas to the third compression pump, and after being compressed to a set pressure, the gas is injected to the core through the gas inlet valve and the inlet valve to displace the water component in the core.

[0011] The second water bath is connected with the water bath jacket of the first compression pump and the third compression pump, and through controlling the circulating flow of the liquid in the jacket, the temperature of the pre-injected gas or liquid is kept constant.

[0012] The back pressure control and collection system includes a back pressure valve and a discharge liquid collection tank; the back pressure valve is connected with the outlet end of the core holder to control the back pressure of the kettle body.

[0013] The first pressure sensor and the second pressure sensor in the data acquisition and analysis device are respectively installed at the inlet end and the outlet end of the core holder to display the inlet and outlet pressures of the core;

[0014] The pressure sensor is installed in the confining pressure cavity of the core holder to display the confining pressure temperature;

[0015] The data acquisition computer is electrically connected with the first pressure sensor, the second pressure sensor, the temperature sensor and the demodulator to output and display the real-time pressure, temperature and strain.

[0016] The core holder is made of lightweight high-strength material with high X-ray transmittance, which is selected from polyether ether ketone resin or carbon fiber composite 7075 aluminum alloy.

[0017] A working method of a real-time monitoring rock core displacement process test system based on optical fiber sensing, comprising the following steps:

[0018] (1) Optical fiber installation: spiral winding a single-mode optical fiber to the surface of a rock core, tightly coupling the single-mode optical fiber and the rock core together with glue, and placing the fixed rock core in a rock core holder for sealing;

[0019] (2) Pre-experiment: opening a vacuum pump valve and a vacuum pump, vacuumizing the whole pipeline system, adjusting the pressure of a back pressure valve to 0, starting a micro-focus CT, and then checking that all valves and pumps are in a closed state to ensure that all devices and pipelines are leak-free;

[0020] (3) Confining pressure loading: filling the confining pressure cavity of the rock core holder and the inner cavity of a piston container with confining pressure liquid and exhausting gas, opening a second water supply valve, controlling a second compression pump to suck liquid in the second solution tank into the pump, closing the second water supply valve, opening a second water inlet valve, and keeping the constant pressure mode to inject liquid into the piston container to load the confining pressure to a given pressure, opening a first water bath and adjusting to a set temperature after the pressure is constant, preheating the solution in the pump and the confining pressure liquid, and opening a circulating pump to make the confining pressure liquid flow circularly after the temperature is stable;

[0021] (4) Gas-liquid preheating-rock core water saturation: after the confining pressure temperature is constant, opening a gas supply valve, controlling a high-pressure gas cylinder to inject gas into a third compression pump, closing the gas supply valve, adjusting the third compression pump to a constant pressure mode to a set pressure, opening a first water supply valve, sucking liquid in the first solution tank into the first compression pump after closing the first water supply valve, and opening a second water bath to a set temperature to preheat the gas and liquid;

[0022] opening a first water inlet valve, an inlet valve, connecting a three-way valve with a liquid outlet after the temperature is constant, injecting ultrapure water into the rock core, and closing the three-way valve after water is discharged from the liquid outlet; opening the three-way valve to discharge tail liquid of the dissolved gas after reaching a constant pressure, repeating the above process until the rock core is completely saturated, closing the first water inlet valve, connecting the three-way valve with a back pressure valve, and adjusting the back pressure valve to a set back pressure;

[0023] (5) Optical fiber monitoring-CT calibration: opening a gas inlet valve, injecting gas into the rock core displacement water component, obtaining the real-time strain state change of each point on the whole single-mode optical fiber through a data acquisition computer, scanning the inside of the rock core through a micro-focus CT, corresponding and fitting the obtained fluid migration front position data and the strain state change position data of the optical fiber monitoring system, achieving the purpose that the fluid migration state in the rock core can be judged through the optical fiber strain image, and the calibration of the whole rock core-optical fiber monitoring system can be completed;

[0024] (6) Signal acquisition-recording-processing: the calibrated core-optical fiber monitoring system is used for experiment, the temperature and pressure signals in the experiment process are converted into data signals through the data acquisition module, and finally are recorded and processed in the data acquisition computer.

[0025] Through the above technical scheme, the present application has the following beneficial effects:

[0026] The present application can comprehensively and systematically study the conventional core displacement experiment, and provide theoretical knowledge for the actual underground CO2 storage; the fluid migration in the core can be overall evaluated and analyzed and visualized by the real-time monitoring system and the CT device based on the optical fiber sensing, instead of the experimental data analysis of the temperature and pressure; the method provided by the present application is simple and easy to understand. BRIEF DESCRIPTION OF DRAWINGS

[0027] The drawings described herein are for illustrative purposes only, and are not intended to limit the scope of the present application in any way. In addition, the shapes and scale sizes of the components in the drawings are only illustrative, and are used to help understand the present application, and are not specific limitations on the shapes and scale sizes of the components of the present application. Those skilled in the art can select various possible shapes and scale sizes according to specific circumstances to implement the present application under the guidance of the present application.

[0028] Figure 1 It is a working principle block diagram of a real-time monitoring core displacement process test system and a visual calibration method based on optical fiber sensing;

[0029] Figure 2 It is a schematic diagram of a real-time monitoring core displacement process test system based on optical fiber sensing;

[0030] In the figure: 1 first solution tank; 2 first water supply valve; 3 first compression pump; 4 first water inlet valve; 5 second solution tank; 6 second water supply valve; 7 second compression pump; 8 third water supply valve; 9 piston container; 10 circulating pump; 11 first water bath; 12 vacuum pump; 13 vacuum pump valve; 14 back pressure valve; 15 discharge liquid collection tank; 16 second pressure sensor; 17 core holder; 18 temperature sensor; 19 micro-focus CT; 20 core; 21 single-mode optical fiber; 22 demodulator; 23 first pressure sensor; 24 data acquisition computer; 25 inlet total valve; 26 air inlet valve; 27 third compression pump; 28 second water bath; 29 high-pressure gas cylinder; 30 gas supply valve; 31 three-way valve.

[0031] Figure 3 It is a schematic diagram of the operation principle of a visual calibration method for real-time monitoring of core displacement process based on optical fiber sensing DETAILED DESCRIPTION

[0032] In order to make the personnel in the technical field better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application.

[0033] A real-time monitoring rock core displacement process test system based on optical fiber sensing includes a visual rock core displacement device, an optical fiber monitoring system, a constant temperature confining pressure loading system, a gas injection-liquid injection switching system, a back pressure control collection system, and a data acquisition and analysis device.

[0034] The visual rock core displacement optical fiber monitoring device includes a rock core holder 17, a rock core 20, and a micro-focus CT 19; the rock core 20 wrapped with a single-mode optical fiber 21 is fixedly placed inside the rock core holder 17, which is used to ensure the sealing of the rock core injection and outflow interfaces; the piston container 9 and the circulating pump 10 are connected with the confining pressure cavity of the rock core holder 17, so as to maintain constant temperature confining pressure; the micro-focus CT 19 internally places the rock core holder 17, so as to obtain the displacement process image of the rock core in the corresponding period and calibrate the monitoring results of the optical fiber system;

[0035] The optical fiber monitoring system includes a single-mode optical fiber 21 and a demodulator 22; the single-mode optical fiber 21 is tightly and spirally wound on the rock core 20 and fixed in the rock core holder 17, so as to detect the strain and temperature change of each point on the rock core 20 in the injection process; the demodulator 22 is connected with the single-mode optical fiber 21 and the data acquisition computer 24, which is used to analyze and process the collected signals and display the corresponding excitation intensity of different points on the optical fiber on the computer in real time.

[0036] The constant temperature confining pressure loading system includes a second solution tank 5, a second water supply valve 6, a second compression pump 7, a second water inlet valve 8, a piston container 9, a circulating pump 10, and a first water bath 11; the second water supply valve 6 controls the second solution tank 5 to inject liquid to the second compression pump 7, and then injects liquid to the piston container 9 through the second water inlet valve 8 and controls the piston container 9 to pressurize the inner cavity liquid and the rock core holder 17 confining pressure to the experimental working condition; the piston container 9 and the circulating pump 10 are immersed in the water bath box and are communicated with the first water bath 11, so as to control the liquid temperature in the piston container 9 to be constant; the circulating pump 10 is connected with the piston container 9 and the confining pressure cavity of the rock core holder 17, which circulates the liquid in the confining pressure cavity to make the temperature in the rock core holder 17 uniform and constant under the condition of ensuring the confining pressure.

[0037] The gas-liquid injection switching system comprises a first solution tank 1, a first water supply valve 2, a first compression pump 3, a first water inlet valve 4, a high-pressure gas cylinder 29, a gas supply valve 30, a second water bath 28, a third compression pump 27, a gas inlet valve 26, and an inlet total valve 25; the first water supply valve 2 controls the first solution tank 1 to inject deionized water into the first compression pump 3, and then the deionized water is injected into the core 20 at a set temperature and pressure through the first water inlet valve 4 and the inlet total valve 25, so as to saturate the core 20; the gas supply valve 30 controls the high-pressure gas cylinder 29 to inject gas into the third compression pump 27, and then the gas is injected into the core 20 through the gas inlet valve 26 and the inlet total valve 25 after being compressed to a set pressure, so as to displace the water component in the core 20; the second water bath 28 is connected with the water bath jacket of the first compression pump 3 and the third compression pump 27, and the temperature of the pre-injected gas or liquid is kept constant by controlling the circulation flow of the liquid in the jacket.

[0038] The back pressure control collection system comprises a back pressure valve 14 and a discharge liquid collection tank 15; the back pressure valve 14 is connected with the outlet end of the core holder 17, and is used to control the back pressure of the kettle body.

[0039] The data acquisition and analysis device comprises a first pressure sensor 23, a second pressure sensor 16, a temperature sensor 18, and a data acquisition computer 24; the first pressure sensor 23 and the second pressure sensor 16 are respectively installed at the inlet end and the outlet end of the core holder 17, and are used to display the pressure at the inlet and outlet of the core; the pressure sensor 18 is installed in the confining pressure cavity of the core holder 17, and is used to display the confining pressure temperature; the data acquisition computer 24 is connected with the first pressure sensor 23, the second pressure sensor 16, the temperature sensor 18, and the demodulator 22, and is used to output and display the real-time pressure, temperature and strain.

[0040] The core holder 17 is made of polyether ether ketone resin peek material, and has a light weight; and an optical fiber sealing joint is arranged at the port, so as to meet the load bearing standard of the object table of the microfocus CT 19 and ensure that the core chamber is sealed perfectly.

[0041] When the above technical scheme works,

[0042] (1) Fiber installation: the single-mode optical fiber 21 is spirally wound to the surface of the core 20, and the single-mode optical fiber 21 and the core 20 are tightly coupled together, first fixed along the spiral line with glue, and then coated with a layer of glue for waterproofing; after the glue solidifies, the whole is wrapped with a heat shrink tube, and after being fixed, is placed in the core holder 17 for sealing;

[0043] (2) Pre-experiment: open the vacuum pump valve 13 and the vacuum pump 12, vacuumize the whole pipeline system, adjust the pressure of the back pressure valve 14 to 0, start the microfocus CT 19, and then check that all valves and pumps are in the closed state, so as to ensure that all devices and pipelines are leak-free;

[0044] (3) Confining pressure loading: Fill the confining pressure chamber of the core holder 17 and the inner cavity of the piston container 9 with confining pressure liquid and purge the gas in advance. Open the second water supply valve 6 and control the second compression pump 7 to draw the liquid in the second solution tank 5 into the pump. Close the second water supply valve 6 and open the second water inlet valve 8. Maintain constant pressure mode to inject the liquid into the piston container 9 to load the confining pressure to 13MPa. After the pressure is constant, open the first water bath 11 and adjust it to 50℃ to preheat the solution in the pump and the confining pressure liquid. After the temperature is stable, open the circulation pump 10 to make the confining pressure liquid circulate.

[0045] (4) Gas-liquid preheating - core water saturation: After the confining pressure temperature is constant, open the gas supply valve 30, control the high-pressure gas cylinder 29 to inject gas into the third compression pump 27, close the gas supply valve 30, adjust the third compression pump 27 to constant pressure mode to 10MPa, open the first water supply valve 2, suck the liquid in the first solution tank 1 into the first compression pump 3, and then close the first water supply valve 2, open the second water bath 28 and adjust it to 50℃ to preheat the gas and liquid. After the temperature is constant, open the first water inlet valve 4 and the inlet valve 25, connect the three-way valve 31 to the drain port, inject ultrapure water into the core 20 at a constant pressure of 5MPa until water comes out of the drain port, then close the three-way valve 31. After reaching a constant pressure, keep it open for a period of time and then open the three-way valve 31 to discharge the tail liquid of dissolved gas. Repeat this until the core is completely saturated, then close the water inlet valve 4, connect the three-way valve 31 to the back pressure valve 14, and adjust the back pressure valve 14 to the set 10MPa.

[0046] (5) Fiber Optic Monitoring-CT Calibration: Open the air inlet valve 26 and inject gas into the core 20 at a constant flow rate of 0.4 mL / min to displace the water components. The real-time strain state changes at various points on the entire single-mode fiber 21 can be obtained through the data acquisition computer 24. At the same time, the interior of the core 20 is scanned by the micro-focus CT 19 to obtain real-time displacement state images of multiple time points within the core 20, such as... Figure 3 As shown, the contrast and brightness parameters were adjusted using ImageJ software to obtain a clear displacement leading edge. The position of the leading edge relative to the whole core was located by comparing it with the scale. The time corresponding to the current displacement state was recorded, and the fiber strain curve corresponding to the same time node was found. The inflection point of the curve was located as the position (a, b, c) of the corresponding displacement leading edge. The entire fiber was located sequentially according to the entire displacement process to complete the calibration of the entire core-fiber monitoring system, so as to achieve the purpose of being able to judge the displacement state inside core 20 through fiber strain diagram.

[0047] (6) Signal acquisition-recording-processing: The calibrated system is used for the experiment. The temperature and pressure signals during the entire experiment are converted into data signals by the data acquisition module and finally collected in the data acquisition computer 24 for recording and processing.

Claims

1. A working method for a real-time monitoring test system for rock core displacement processes based on fiber optic sensing, characterized in that, The system includes a visualized core displacement device, a fiber optic monitoring system, a constant temperature and confining pressure loading system, a gas injection-liquid injection switching system, a back pressure control and collection system, and a data acquisition and analysis device. The rock core (20) wrapped with single-mode optical fiber (21) is fixedly placed inside the rock core holder (17) of the visualization rock core displacement device, and an optical fiber sealing connector is provided at the port to ensure the sealing of the rock core injection and outflow interface; the piston container (9) and the circulation pump (10) are connected to the confining pressure cavity of the rock core holder (17) to maintain constant temperature and pressure; the rock core holder (17) is placed inside the micro-focus CT (19) to obtain images of the internal displacement process of the rock core in the corresponding time period and to calibrate the monitoring results of the optical fiber system; The single-mode fiber (21) in the fiber optic monitoring system is spirally wound on the rock core (20) and fixed in the rock core holder (17) to detect the strain and temperature changes of each sensing unit on the rock core (20) during the injection process; the demodulator (22) is connected to the single-mode fiber (21) and the data acquisition computer (24) to analyze and process the acquired signals and display the excitation intensity corresponding to different positions on the fiber on the computer in real time. The second water supply valve (6) in the constant temperature confining pressure loading system controls the second solution tank (5) to inject liquid into the second compression pump (7), and then injects liquid into the piston container (9) through the second water inlet valve (8) and controls it to pressurize the liquid in the inner cavity and the core holder (17) to the experimental conditions; the piston container (9) and the circulation pump (10) are immersed in the water bath and connected to the first water bath (11) to control the liquid temperature in the piston container (9) to reach a constant; the circulation pump (10) is connected to the confining pressure cavity of the piston container (9) and the core holder (17), and by controlling the liquid circulation flow in the confining pressure cavity, the internal temperature of the core holder (17) is kept uniform and constant while ensuring the confining pressure; This working method includes the following steps: (1) Fiber optic installation: The single-mode fiber (21) is spirally wound onto the surface of the rock core (20), and the single-mode fiber (21) and the rock core (20) are tightly coupled together with glue. After fixing, it is placed in the rock core holder (17) and sealed. (2) Experimental preparation: Open the vacuum pump valve (13) and vacuum pump (12) to evacuate the entire pipeline system, adjust the back pressure valve (14) pressure to 0, start the microfocus CT (19), and then check that all valves and pumps are closed to ensure that all devices and pipelines are leak-free. (3) Confining pressure loading: Fill the confining pressure chamber of the core holder (17) and the inner cavity of the piston container (9) with confining pressure liquid and purge the gas in advance. Open the second water supply valve (6) and control the second compression pump (7) to suck the liquid in the second solution tank (5) into the pump. Close the second water supply valve (6) and open the second water inlet valve (8). Maintain constant pressure mode to inject the liquid into the piston container (9) to load the confining pressure to the given pressure. After the pressure is constant, open the first water bath (11) and adjust it to the set temperature to preheat the solution in the pump and the confining pressure liquid. After the temperature is stable, open the circulation pump (10) to make the confining pressure liquid circulate. (4) Gas-liquid preheating - core water saturation: After the confining pressure temperature is constant, open the gas supply valve (30) and control the high-pressure gas cylinder (29) to inject gas into the third compression pump (27), and close the gas supply valve (30); adjust the third compression pump (27) to constant pressure mode to the set pressure, open the first water supply valve (2), suck the liquid in the first solution tank (1) into the first compression pump (3), and then close the first water supply valve (2). Open the second water bath (28) and adjust it to the set temperature to preheat the gas and liquid; After the temperature is constant, open the first water inlet valve (4) and the main inlet valve (25), connect the three-way valve (31) to the drain port, inject ultrapure water into the core (20) until water comes out of the drain port and then close the three-way valve (31); after the constant pressure is reached, open the three-way valve (31) to discharge the tail liquid of dissolved gas, repeat the above process until the core is completely saturated, close the first water inlet valve (4), connect the three-way valve (31) to the back pressure valve (14), and adjust the back pressure valve (14) to the set back pressure; (5) Fiber optic monitoring-CT calibration: Open the air inlet valve (26) and inject gas into the core (20) to displace water components. The real-time strain state changes of each point on the entire single-mode fiber (21) are obtained through the data acquisition computer (24). At the same time, the core (20) is scanned by the micro-focus CT (19) to obtain the real-time displacement state image inside the core (20). The contrast and brightness are adjusted using the imagej software to obtain a clear displacement front edge. The position of the front edge relative to the core is located by comparing it with the scale. The time corresponding to the current displacement state is recorded. The fiber strain curve corresponding to the same time node is found. The inflection point of the curve is the position of the corresponding displacement front edge. The entire fiber is located sequentially according to the entire displacement process to complete the calibration of the entire core-fiber optic monitoring system and achieve the purpose of judging the displacement state inside the core (20) through the fiber strain diagram. (6) Signal acquisition-recording-processing: The calibrated core-fiber monitoring system was used for the experiment. The temperature and pressure signals during the experiment were converted into data signals by the data acquisition module and finally collected in the data acquisition computer (24) for recording and processing.

2. The working method according to claim 1, characterized in that: In the gas injection-liquid injection switching system, the first water supply valve (2) controls the first solution tank (1) to inject deionized water into the first compression pump (3), and then injects deionized water into the core (20) at a set temperature and pressure through the first water inlet valve (4) and the inlet main valve (25) to saturate the core (20). The gas supply valve (30) controls the high-pressure gas cylinder (29) to inject gas into the third compression pump (27), and after being compressed to the set pressure, the gas is injected into the rock core (20) through the inlet valve (26) and the main inlet valve (25) to displace the water components in the rock core (20).

3. The working method according to claim 2, characterized in that: The second water bath (28) is connected to the water bath jacket of the first compression pump (3) and the third compression pump (27), and the temperature of the pre-injected gas or liquid is kept constant by controlling the circulation of liquid in the jacket.

4. The working method according to claim 3, characterized in that: The back pressure control and collection system includes a back pressure valve (14) and a discharge liquid collection tank (15); the back pressure valve (14) is connected to the outlet end of the core holder (17) to control the back pressure of the vessel.

5. The working method according to claim 4, characterized in that: The first pressure sensor (23) and the second pressure sensor (16) in the data acquisition and analysis device are respectively installed at the inlet and outlet ends of the core holder (17) to display the core inlet and outlet pressures; A temperature sensor (18) is installed inside the confining pressure chamber of the core holder (17) to display the temperature of the confining pressure chamber; The data acquisition computer (24) is electrically connected to the first pressure sensor (23), the second pressure sensor (16), the temperature sensor (18), and the demodulator (22) respectively, to output and display real-time pressure, temperature and strain.

6. The working method according to claim 5, characterized in that: The core holder (17) is made of a lightweight, high-strength material with high X-ray transmittance, selected from polyetheretherketone resin or carbon fiber composite 7075 aluminum alloy.

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