Salt rock permeability testing device based on temperature and pressure monitoring and testing method thereof

Abstract

The invention provides a salt rock permeability testing device based on temperature and pressure monitoring, and the device comprises a confining pressure chamber which is internally provided with a pressurization space; the fixing module is arranged in the pressurizing space and is used for fixing a to-be-tested sample; the confining pressure loading module comprises an oil injection part and an oil discharge part, the oil injection part is communicated with the bottom of the pressurization space, and the oil discharge part is communicated with the top of the pressurization space; the gas injection pressure loading module penetrates through the confining pressure chamber and is communicated with the top of the fixing module; the gas flow monitoring module comprises a low-flow monitoring piece and a high-flow monitoring piece, one end of the low-flow monitoring piece penetrates through the confining pressure chamber to be communicated with the bottom of the fixing module, and the other end of the low-flow monitoring piece is communicated with the high-flow monitoring piece; and the data acquisition and analysis module is in communication connection with the confining pressure loading module, the gas injection pressure loading module and the gas flow monitoring module. According to the salt rock permeability testing device, the permeability of ultra-low permeability media such as salt rock can be accurately measured.

Description

Technical Field

[0001] This invention belongs to the technical field of salt cavern gas storage, and specifically relates to a salt rock permeability testing device and its testing method based on temperature and pressure monitoring. Background Technology

[0002] China is a major energy consumer, with fossil fuels such as coal and oil still dominating its energy system. To reduce dependence on fossil fuels and decrease carbon dioxide emissions, China has formulated a carbon peaking and carbon neutrality strategy. Natural gas is a clean energy source; when burned, it emits 34.2% less carbon dioxide than oil and 53.5% less than coal for the same heat output. Natural gas plays a crucial role in the energy consumption revolution and the low-carbon transition of energy. With the advancement of the "dual-carbon" strategy, my country's natural gas consumption continues to grow. However, there is a mismatch between natural gas production and consumption in time and space. To ensure a stable supply of natural gas, gas storage facilities are needed to achieve supply and demand balance. Salt cavern gas storage facilities utilize cavities formed by water-soluble salt extraction from underground salt layers to store natural gas. They are characterized by stability and high injection-production efficiency, making them ideal gas storage sites. Because natural gas and other energy sources are flammable and explosive, airtightness evaluation is a crucial technology for ensuring the safe operation of gas storage facilities, and salt layer permeability is an important parameter for conducting salt cavern airtightness evaluations.

[0003] Because salt rock is buried thousands of meters underground, its permeability is difficult to measure directly. Currently, the permeability of a sample is usually determined by indoor permeability testing using the steady-state method. However, due to the extremely low permeability of ultra-low permeability media such as salt rock, the gas flow rate generated during the steady-state permeability testing process is very small. When the flow rate is less than 0.1 ml / min, existing gas flow meters generally cannot accurately monitor the gas flow rate, resulting in the inability to accurately measure the permeability of salt rock.

[0004] Therefore, how to provide a salt rock permeability testing device based on temperature and pressure monitoring to achieve accurate measurement of the permeability of ultra-low permeability media such as salt rock is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that in the prior art, when determining the permeability of a sample by indoor permeability testing using the steady-state method, the existing gas flow meter is difficult to accurately monitor the gas flow rate when the flow rate is less than 0.1 ml / min, resulting in the permeability of salt rock not being accurately measured.

[0006] To address the aforementioned problems, a first aspect of the present invention provides a salt rock permeability testing device based on temperature and pressure monitoring, comprising: a confining pressure chamber having a pressurized space; a fixing module disposed inside the pressurized space for fixing a test sample; a confining pressure loading module including an oil injection component and an oil discharge component, the oil injection component being connected to the bottom of the pressurized space and the oil discharge component being connected to the top of the pressurized space; a gas injection pressure loading module passing through the confining pressure chamber and connected to the top of the fixing module; a gas flow monitoring module including a low flow monitoring component and a high flow monitoring component, one end of the low flow monitoring component passing through the confining pressure chamber and connected to the bottom of the fixing module, and the other end of the low flow monitoring component being connected to the high flow monitoring component; and a data acquisition and analysis module communicatively connected to the confining pressure loading module, the gas injection pressure loading module, and the gas flow monitoring module.

[0007] In the first aspect, the fixing module includes: an upper pressure head, which is cylindrical in shape and disposed at the top of the pressurization space. The upper pressure head has a gas inflow channel inside, one end of which contacts the top surface of the sample to be tested, and the other end of which is connected to the gas injection pressure loading module; a lower pressure head, which is cylindrical in shape and disposed at the bottom of the pressurization space. The sample to be tested is installed between the upper and lower pressure heads. The lower pressure head has a gas outflow channel inside, one end of which contacts the bottom surface of the sample to be tested, and the other end of which is connected to the low-flow monitoring device; a pressure rod, disposed at the top of the confining pressure chamber, with its bottom surface contacting the top surface of the upper pressure head; and a confining pressure chamber base, which is installed at the bottom of the confining pressure chamber and connected to the lower pressure head.

[0008] In the first aspect, the low-flow monitoring device includes an exhaust pipe, a gas collecting pipe, a recovery bottle, a recovery bottle valve, and a temperature transmitter. One end of the exhaust pipe passes through the base of the confining pressure chamber and the bottom of the confining pressure chamber, and is connected to the gas outflow channel. One end of the gas collecting pipe is connected to the middle of the exhaust pipe, and the other end of the gas collecting pipe is connected to the recovery bottle. The recovery bottle valve is disposed on the gas collecting pipe. The temperature transmitter is communicatively connected to the data acquisition and analysis module. The high-flow monitoring device includes a gas pressure transmitter, a gas solenoid valve, and a gas flow meter. The gas pressure transmitter, the gas solenoid valve, and the gas flow meter are sequentially arranged adjacent to each other at the other end of the exhaust pipe from one end to the other end. The gas pressure transmitter, the gas solenoid valve, and the gas flow meter are communicatively connected to the data acquisition and analysis module.

[0009] In the first aspect, the gas injection pressure loading module includes: a gas injection pipe, one end of which passes through the base of the confining pressure chamber and the bottom of the confining pressure chamber and is connected to the gas inflow channel; a gas injection component, which includes a gas cylinder, a gas cylinder pressure gauge, and a gas cylinder valve, the gas cylinder being connected to the other end of the gas injection pipe, the gas cylinder pressure gauge and the gas cylinder valve being arranged adjacently along the gas inflow channel toward the gas cylinder at the other end of the gas injection pipe, the gas cylinder pressure gauge being communicatively connected to the data acquisition and analysis module; and a pressure regulating component, which includes a gas pump valve, a gas pump pressure gauge, and a gas injection pump, the gas pump valve, the gas pump pressure gauge, and the gas injection pump being arranged adjacently along the gas inflow channel toward the gas cylinder on the gas injection pipe, the gas pump pressure gauge being communicatively connected to the data acquisition and analysis module.

[0010] In the first aspect, the oil injection component includes an oil injection pipe, an oil injection pump, a first solenoid valve, and a confining pressure gauge. One end of the oil injection pipe passes through the confining pressure chamber and is connected to the bottom of the pressurized space. The oil injection pump, the first solenoid valve, and the confining pressure gauge are sequentially arranged adjacent to each other on the oil injection pipe from the other end toward one end of the oil injection pipe. The first solenoid valve and the confining pressure gauge are communicatively connected to the data acquisition and analysis module. The oil discharge component includes an oil discharge pipe and a second solenoid valve. The oil discharge pipe passes through the confining pressure chamber and is connected to the top of the pressurized space. The second solenoid valve is disposed on the oil discharge pipe and is communicatively connected to the data acquisition and analysis module.

[0011] In the first aspect, the data acquisition and analysis module includes: a plurality of data lines; a computer, which is communicatively connected to the temperature transmitter, the gas pressure transmitter, the gas solenoid valve, the gas flow meter, the gas cylinder pressure gauge, the gas pump pressure gauge, the first solenoid valve, the confining pressure gauge, and the second solenoid valve respectively via the plurality of data lines.

[0012] A second aspect of the present invention provides a testing method for a salt rock permeability testing device based on temperature and pressure monitoring, comprising the following steps: preparing a test sample and recording basic experimental data; installing the test sample in the pressurized space of a confining pressure chamber; after installation, applying confining pressure to the confining pressure chamber through a confining pressure loading module; sequentially opening the gas solenoid valve, closing the gas pump valve, and opening the gas cylinder valve to input gas from the gas cylinder into the gas injection pump, then closing the gas cylinder valve, and adjusting the gas pressure to the required experimental pressure using the gas injection pump; after adjustment, opening the gas pump valve, and observing the gas flow meter after a period of time. Can the gas flow rate be monitored? If the gas flow rate can be monitored, record the gas flow rate detected by the gas flow meter at regular intervals to obtain several sets of gas flow rate values. If the gas flow rate cannot be monitored, close the gas solenoid valve and calculate the gas flow rate value at regular intervals using the low flow monitoring device and the basic data. Calculate the permeability of the sample to be tested based on each set of gas flow rate values ​​to obtain several sets of permeability data. Compare the differences between several sets of permeability data, select the permeability data with a permeability change rate of less than 10%, calculate the average permeability, and obtain the measured permeability of the sample to be tested.

[0013] In the second aspect, the gas flow rate value calculated at regular intervals using a low-flow monitoring device and the aforementioned basic data includes: calculating the amount of gas n0 in the recovery bottle, exhaust pipe, and gas collecting pipe during the initial stage according to equation (1): (1); In equation (1), P0 is the pressure inside the recovery bottle, exhaust pipe, and gas collecting pipe in the initial stage, and V b V is the volume of the recycled bottle. L Let Z0 be the volume of the exhaust pipe and the gas collecting pipe, Z0 be the gas compressibility factor at the initial moment, R be the gas constant, and T0 be the ambient temperature at the initial stage; calculate the volume V of the gas in the recovery bottle, exhaust pipe, and gas collecting pipe under standard conditions at the initial stage according to equation (2). g,0 : (2); In equation (2), M is the molar mass of the gas. Let n be the gas density under standard conditions; open the valve of the recovery bottle to allow the gas to enter the recovery bottle, and calculate the amount of substance n of the gas in the recovery bottle, exhaust pipe and gas collecting pipe at time t according to formula (3) at regular intervals. t : (3); In the above formula (3), P t Let Z be the pressure inside the recovery bottle, exhaust pipe, and gas collection pipe at time t. t Let T be the gas compressibility factor at time t. t Let t be the ambient temperature; calculate the standard gas volume V in the recovery bottle, exhaust pipe, and gas collection pipe at time t according to equation (4). g,t : (4); The gas flow rate Q from the initial stage to time t is calculated according to equation (5): (5).

[0014] In the second aspect, calculating the permeability of the test sample based on each set of gas flow rate values ​​includes: calculating the permeability k of the test sample based on each set of gas flow rate values ​​Q and equation (6): (6); In equation (6), P is atmospheric pressure, P up The pressure monitored by the gas pump pressure gauge, P down The pressure is monitored by the gas pressure transmitter, A is the cross-sectional area of ​​the test sample, L is the height of the test sample, and μ is the viscosity of the test gas.

[0015] In the second aspect, the basic data includes the mass of the test sample, the height of the test sample, the inner diameter of the test sample, the cross-sectional area of ​​the test sample, the volume of the recovery bottle, and the volumes of the gas collecting pipe and the exhaust pipe; the installation of the test sample in the pressurized space of the confining pressure chamber includes: opening the confining pressure chamber, connecting the test sample to the upper pressure head and the lower pressure head, and installing the test sample and the upper and lower pressure heads as a whole in the confining pressure chamber, then connecting the gas injection pipe to the upper pressure head and the exhaust pipe to the lower pressure head, closing the confining pressure chamber after connection, and tightly connecting the confining pressure chamber to the confining pressure chamber base with bolts; the application of confining pressure to the confining pressure chamber through the confining pressure loading module includes: opening the first solenoid valve and the second solenoid valve, injecting hydraulic oil into the confining pressure chamber through the oil injection pump, closing the second solenoid valve when the hydraulic oil fills the entire confining pressure chamber and flows out from the oil discharge pipe, and using the oil injection pump to raise the confining pressure in the pressurized space to the confining pressure required for the experiment.

[0016] Beneficial Effects: The salt rock permeability testing device based on temperature and pressure monitoring proposed in this invention includes a confining pressure chamber, a fixing module, a confining pressure loading module, a gas injection pressure loading module, a gas flow monitoring module, and a data acquisition and analysis module. The test sample is fixed by the fixing module located inside the pressurized space within the confining pressure chamber. The oil injection component of the confining pressure loading module is connected to the bottom of the pressurized space to inject hydraulic oil into the pressurized space, applying confining pressure to the test sample and simulating the stress state of the test sample under actual geological conditions. The oil discharge component is connected to the top of the pressurized space to discharge the hydraulic oil from the confining pressure chamber. The gas injection pressure loading module passes through the confining pressure chamber and is connected to the top of the fixing module. One end of the low-flow monitoring component of the gas flow monitoring module passes through the confining pressure chamber and is connected to the bottom of the fixing module, while the other end is connected to the high-flow monitoring component. The gas injection pressure loading module injects gas into the top of the test sample in the fixed module, allowing the gas to flow out from the bottom of the test sample to the gas flow monitoring module for permeability testing. When the permeability of the test sample is low, the gas flow rate can be monitored by the low flow rate monitoring device to calculate the permeability of ultra-low permeability media, thus achieving accurate measurement of the permeability of ultra-low permeability media such as salt rock. When the permeability of the test sample is high, the gas flow rate can be monitored by the high flow rate monitoring device, enabling the salt rock permeability testing device to also test the permeability of other rock samples with higher permeability. The data acquisition and analysis module communicates with the confining pressure loading module, the gas injection pressure loading module, and the gas flow monitoring module. It can collect data detected by the confining pressure loading module, the gas injection pressure loading module, and the gas flow monitoring module, and analyze and process the data. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the salt rock permeability testing device provided in the embodiments of the present invention; Figure 2 This is a flowchart of the testing method provided in the embodiments of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Confining pressure chamber; 2. Fixed module; 21. Upper pressure head; 22. Gas inflow channel; 23. Lower pressure head; 24. Gas outflow channel; 25. Pressure rod; 26. Confining pressure chamber base; 3. Confining pressure loading module; 31. Oil injection component; 311. Oil injection pipe; 312. Oil injection pump; 313. First solenoid valve; 314. Confining pressure gauge; 32. Oil discharge component; 321. Oil discharge pipe; 322. Second solenoid valve; 4. Gas injection pressure loading module; 41. Gas injection pipe; 42. Gas injection component; 421. Gas cylinder; 422. Gas cylinder pressure gauge; 423. Gas cylinder valve; 43. Pressure regulating component; 431. Air pump valve; 432. Air pump pressure gauge; 433. Gas injection pump; 5. Gas flow monitoring module; 51. Low flow monitoring device; 511. Exhaust pipe; 512. Gas collection pipe; 513. Recovery bottle; 514. Recovery bottle valve; 515. Temperature transmitter; 52. High flow monitoring device; 521. Gas pressure transmitter; 522. Gas solenoid valve; 523. Gas flow meter; 6. Data acquisition and analysis module; 61. Data cable; 62. Computer; 7. Test sample. Detailed Implementation

[0021] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0022] Furthermore, throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0023] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0024] Example 1 like Figure 1As shown, this embodiment provides a salt rock permeability testing device based on temperature and pressure monitoring, including a confining pressure chamber 1, a fixing module 2, a confining pressure loading module 3, a gas injection pressure loading module 4, a gas flow monitoring module 5, and a data acquisition and analysis module 6. The confining pressure chamber 1 has a pressurized space; the fixing module 2 is disposed inside the pressurized space and is used to fix the test sample 7; the confining pressure loading module 3 includes an oil injection component 31 and an oil discharge component 32, the oil injection component 31 being connected to the bottom of the pressurized space, and the oil discharge component 32 being connected to the top of the pressurized space; the gas injection pressure loading module 4 passes through the confining pressure chamber 1. The pressure chamber 1 is connected to the top of the fixed module 2; the gas flow monitoring module 5 includes a low flow monitoring element 51 and a high flow monitoring element 52. One end of the low flow monitoring element 51 passes through the pressure chamber 1 and is connected to the bottom of the fixed module 2, and the other end of the low flow monitoring element 51 is connected to the high flow monitoring element 52; the data acquisition and analysis module 6 is communicatively connected to the pressure loading module 3, the gas injection pressure loading module 4, and the gas flow monitoring module 5. The data acquisition and analysis module 6 is used to acquire and analyze the data from the pressure loading module 3, the gas injection pressure loading module 4, and the gas flow monitoring module 5. The test sample 7 is a salt rock sample. The pressure chamber 1 has an internally hollow cylindrical sealed structure and is made of stainless steel. The pressure chamber can achieve liquid or gas sealing under high pressure conditions.

[0025] Specifically, the salt rock permeability testing device based on temperature and pressure monitoring proposed in this invention includes a confining pressure chamber 1, a fixing module 2, a confining pressure loading module 3, a gas injection pressure loading module 4, a gas flow monitoring module 5, and a data acquisition and analysis module 6. The test sample 7 is fixed by the fixing module 2, which is located inside the pressurized space within the confining pressure chamber 1. The oil injection component 31 of the confining pressure loading module 3 is connected to the bottom of the pressurized space to inject hydraulic oil into the pressurized space, thereby applying confining pressure to the test sample 7 within the pressurized space and simulating the stress state of the test sample 7 under actual geological conditions. The oil discharge component 3... 2 is connected to the top of the pressurized space to discharge the hydraulic oil in the confining pressure chamber 1 through the oil drain component 32; the gas injection pressure loading module 4 passes through the confining pressure chamber 1 and is connected to the top of the fixed module 2; one end of the low flow monitoring component 51 of the gas flow monitoring module 5 passes through the confining pressure chamber 1 and is connected to the bottom of the fixed module 2, and the other end is connected to the high flow monitoring component 52. Gas can be injected into the top of the test sample 7 in the fixed module 2 through the gas injection pressure loading module 4, so that the gas flows out from the bottom of the test sample 7 to the gas flow monitoring module 5 for permeability testing of the test sample 7; when the permeability of the test sample 7 is low (10 -21 m 2When the gas flow rate is high (10), the gas flow rate can be monitored by the low flow rate monitoring device 51 to calculate the permeability of the ultra-low permeability medium, thereby achieving accurate measurement of the permeability of ultra-low permeability media such as salt rock. -12 m 2 ~10 -21 m 2 When the gas flow rate is monitored by the high flow rate monitoring element 52, the salt rock permeability testing device can also be used to test the permeability of other rock samples with higher permeability. The data acquisition and analysis module 6 is connected to the confining pressure loading module 3, the gas injection pressure loading module 4 and the gas flow rate monitoring module 5. The data acquisition and analysis module 6 can store the data detected by the confining pressure loading module 3, the gas injection pressure loading module 4 and the gas flow rate monitoring module 5 and analyze and process the data.

[0026] In some possible implementations, the fixing module 2 includes: an upper pressure head 21, which is cylindrical in shape and disposed at the top of the pressurization space. A gas inflow channel 22 is provided inside the upper pressure head 21, one end of which contacts the top surface of the test sample 7, and the other end of which is connected to the gas injection pressure loading module 4; and a lower pressure head 23, which is cylindrical in shape and disposed at the bottom of the pressurization space. The test sample 7 is mounted on the upper pressure head 23. Between the pressure head 21 and the lower pressure head 23, a gas outflow channel 24 is provided inside the lower pressure head 23. One end of the gas outflow channel 24 contacts the bottom surface of the test sample 7, and the other end of the gas outflow channel 24 is connected to the low flow monitoring element 51. A pressure rod 25 is embedded in the top of the confining pressure chamber 1, and the bottom surface of the pressure rod 25 contacts the top surface of the upper pressure head 21. A confining pressure chamber base 26 is bolted to the bottom of the confining pressure chamber 1 and connected to the lower pressure head 23. Both the upper pressure head 21 and the lower pressure head 23 are made of stainless steel.

[0027] Those skilled in the art will understand that the cylindrical upper pressure head 21 is positioned at the top of the pressurized space. One end of the gas inflow channel 22 inside the upper pressure head 21 contacts the top surface of the test sample 7, and the other end is connected to the gas injection pressure loading module 4. The cylindrical lower pressure head 23 is positioned at the bottom of the pressurized space. The test sample 7 is installed between the upper pressure head 21 and the lower pressure head 23. One end of the gas outflow channel 24 inside the lower pressure head 23 contacts the bottom surface of the test sample 7, and the other end is connected to the low flow rate monitoring element 51. The test sample 7 can be fixed by clamping it from the top and bottom of the test sample 7 by the upper pressure head 21 and the lower pressure head 23, respectively. Gas from the gas injection pressure loading module 4 is delivered to the top of the test sample 7 through the gas inflow channel 22, so that the gas is injected into the test sample 7 from the top and flows out from the gas outflow channel 24 at the bottom into the low flow monitoring element 51; the bottom surface of the pressure rod 25 set at the top of the confining pressure chamber 1 is in contact with the top surface of the upper pressure head 21. When the confining pressure is applied, the pressure rod 25 can apply downward pressure to the upper pressure head 21 to ensure that the upper pressure head 21 is in contact with the test sample and does not detach; the confining pressure chamber base 26 is installed at the bottom of the confining pressure chamber 1 and connected to the lower pressure head 23. The confining pressure chamber base 26 can provide reaction force to the lower pressure head 23 and the test sample 7 through the confining pressure chamber base 26, and ensure that the confining pressure chamber 1 does not move when the confining pressure is applied.

[0028] In some possible implementations, the low-flow monitoring device 51 includes an exhaust pipe 511, a gas collecting pipe 512, a recovery bottle 513, a recovery bottle valve 514, and a temperature transmitter 515. One end of the exhaust pipe 511 passes through the confining chamber base 26, and the bottom of the confining chamber 1 is connected to the gas outlet channel 24 via a connector. The other end of the exhaust pipe 511 is connected to the outside atmosphere. One end of the gas collecting pipe 512 is connected to the middle of the exhaust pipe 511, and the other end of the gas collecting pipe 512 is connected to the recovery bottle 513. The recovery bottle valve 514 is disposed on the gas collecting pipe 512. The temperature transmitter 515 is communicatively connected to the data acquisition and analysis module 6. The high-flow monitoring device 52 includes a gas pressure transmitter 521, a gas solenoid valve 522, and a gas flow meter 523. The gas pressure transmitter 521, the gas solenoid valve 522, and the gas flow meter 523 are sequentially arranged adjacent to each other at the other end of the exhaust pipe 511. The gas pressure transmitter 521, the gas solenoid valve 522, the gas flow meter 523, and the temperature transmitter 515 are communicatively connected to the data acquisition and analysis module 6. The minimum range of the gas flow meter is 0.1 ml / min, and the range of the gas pressure transmitter 521 is much smaller than the gas pressure applied to the test sample during the experiment.

[0029] This is because one end of the exhaust pipe 511 passes through the base 26 of the confining pressure chamber 1 and is connected to the gas outlet channel 24. When gas seeps out from the bottom of the sample to be tested, the gas flows into the gas outlet channel 24 inside the pressure head 23 and finally into the exhaust pipe 511. One end of the gas collecting pipe 512 is connected to the middle of the exhaust pipe 511, and the other end is connected to the recovery bottle 513, so that the gas from the exhaust pipe 511 is passed into the recovery bottle 513 through the gas collecting pipe 512, and the gas flowing out from the exhaust pipe is collected through the recovery bottle 513. The recovery bottle valve 514 provided on the gas collecting pipe 512 can be used to control whether the gas from the exhaust pipe 511 flows into the recovery bottle 513 for storage. The gas pressure transmitter 521, gas solenoid valve 522, and gas flow meter 523 are arranged sequentially and adjacently at one end of the exhaust pipe 511 towards the other end. The gas pressure transmitter 521 is used to monitor the gas pressure in the recovery bottle 513, the exhaust pipe 511, and the gas collecting pipe 512. The gas solenoid valve 522 is used to control whether the exhaust pipe 511 is connected to the atmosphere. The gas flow meter 523 is used to monitor the flow rate of the gas discharged from the exhaust pipe 511. The minimum range of the gas flow meter 523 is 0.1 ml / min, which means that the gas flow meter 523 can only monitor gas flow rates greater than 0.1 ml / min. When the gas flow rate is greater than 0.1 ml / min, close the recovery bottle valve 514 and open the gas solenoid valve 522 to allow the gas from the exhaust pipe 511 to pass through the gas flow meter 523, so that the gas flow rate can be monitored by the gas flow meter 523. When the test sample 7 is an ultra-low permeability medium, the gas flow rate during the permeability test may be much less than 0.1 ml / min. In this case, open the recovery bottle valve 514 and close the gas solenoid valve 522, so that the gas from the exhaust pipe 511 flows into the recovery bottle 513 through the gas collecting pipe 512. As the gas gradually flows into the recovery bottle 513, the pressure of the recovery bottle 513, the gas collecting pipe 512 and the exhaust pipe 511 gradually increases. The gas pressure transmitter 521 can monitor the pressure change of the recovery bottle 513, the gas collecting pipe 512 and the exhaust pipe 511 over time in real time. When the gas pressure in the recovery bottle 513 exceeds the range of the gas pressure transmitter 521, open the gas solenoid valve 522 to allow the gas in the recovery bottle 513 to be discharged from the exhaust pipe 511. The range of the gas pressure transmitter 521 is much smaller than the gas pressure applied to the test sample during the experiment. Therefore, the increase in gas pressure in the recovery bottle 513 has little effect on the gas permeation rate. The gas pressure transmitter 521, gas solenoid valve 522, gas flow meter 523, and temperature transmitter 515 are connected to the data acquisition and analysis module 6. The ambient atmospheric temperature is monitored in real time through the temperature transmitter 28. The data acquisition and analysis module 6 can store and analyze the data monitored by the gas pressure transmitter 521, gas flow meter 523, and temperature transmitter 515, and control the opening and closing of the gas solenoid valve 522.

[0030] In some possible implementations, the gas injection pressure loading module 4 includes: a gas injection pipe 41, one end of which passes through the confining pressure chamber base 26, and the bottom of the confining pressure chamber 1 is connected to the gas inflow channel 22 via a connector; and a gas injection component 42, which includes a gas cylinder 421, a gas cylinder pressure gauge 422, and a gas cylinder valve 423, the gas cylinder 421 being connected to the other end of the gas injection pipe 41, and the gas cylinder pressure gauge 422 and the gas cylinder valve 423 flowing along the gas inflow channel 22 into the gas cylinder 421. The gas cylinder pressure gauge 422 is communicatively connected to the data acquisition and analysis module 6 at the other end of the gas injection pipe 41; the pressure regulating component 43 includes a gas pump valve 431, a gas pump pressure gauge 432, and a gas injection pump 433. The gas pump valve 431, the gas pump pressure gauge 432, and the gas injection pump 433 are arranged adjacent to each other on the gas injection pipe 41 along the gas inflow channel 22 toward the gas cylinder 421. The gas pump pressure gauge 432 is communicatively connected to the data acquisition and analysis module 6.

[0031] This is because one end of the gas injection pipe 41 passes through the base 26 of the confining pressure chamber 1 and the bottom of the confining pressure chamber 1, and is connected to the gas inflow channel 22. The other end is connected to the gas cylinder 421 of the gas injection component 42. The gas cylinder 421 can be used as a storage container for the gas required for permeability testing. The gas in the gas cylinder can be transported to the upper pressure head 21 and enter the top of the test sample 7 through the gas injection pipe 41. The gas cylinder pressure gauge 422 and the gas cylinder valve 423 are arranged adjacent to each other at the other end of the gas injection pipe 41 along the gas inflow channel 22 toward the gas cylinder 421. The gas cylinder valve 423 is used to control the flow rate of gas into the gas injection pipe 41, and the gas cylinder pressure gauge 422 is used to monitor the pressure inside the gas cylinder 421. The air pump valve 431, the air pump pressure gauge 432, and the gas injection pump 433 of the pressure regulating component 43 are connected to the gas cylinder 421 along the gas inflow channel 22. The gas cylinders 421 and 432 are arranged sequentially and adjacently on the gas injection pipe 41. The gas can be pressurized or depressurized by the gas injection pump 433 to reach the test pressure. The gas injection pump 433 is connected to the gas cylinder 421 through the gas injection pipe 41. When the gas cylinder valve 423 is opened, the gas enters the gas injection pump 433 from the gas cylinder 421. When the gas pressure is less than or greater than the required test pressure, the gas injection pump 433 automatically starts and adjusts the gas pressure by reciprocating piston motion. The gas pressure gauge 432 is used to monitor the gas pressure in the gas injection pump 433, and the gas pump valve 431 is used to control the flow rate of gas into the gas injection pipe 41. The gas cylinder pressure gauge 422 and the gas pump pressure gauge 432 are communicatively connected to the data acquisition and analysis module 6, which can store and analyze the data monitored by the gas cylinder pressure gauge 422 and the gas pump pressure gauge 432.

[0032] In some possible implementations, the oil injection component 31 includes an oil injection pipe 311, an oil injection pump 312, a first solenoid valve 313, and a confining pressure gauge 314. One end of the oil injection pipe 311 passes through the confining pressure chamber 1 and is connected to the bottom of the pressurized space. The oil injection pump 312, the first solenoid valve 313, and the confining pressure gauge 314 are sequentially arranged adjacent to each other on the oil injection pipe 311 from the other end of the oil injection pipe 311 toward one end of the oil injection pipe 311. The first solenoid valve 313 and the confining pressure gauge 314 are communicatively connected to the data acquisition and analysis module 6. The oil discharge component 32 includes an oil discharge pipe 321 and a second solenoid valve 322. The oil discharge pipe 321 passes through the confining pressure chamber 1 and is connected to the top of the pressurized space. The second solenoid valve 322 is disposed on the oil discharge pipe 321 and is communicatively connected to the data acquisition and analysis module 6. The other end of the oil injection pipe 311 can be connected to an external oil storage device, which is filled with hydraulic oil.

[0033] Those skilled in the art will understand that one end of the oil injection pipe 311 passes through the confining pressure chamber 1 and is connected to the bottom of the pressurized space. The oil injection pump 312, the first solenoid valve 313, and the confining pressure gauge 314 are sequentially arranged adjacent to each other along the other end of the oil injection pipe 311 towards one end of the oil injection pipe 311. The oil injection pump 312 can pump hydraulic oil into the confining pressure chamber 1 through the oil injection pipe 311. At the same time, the oil injection pump 312 can compress the hydraulic oil to generate high pressure, so that the hydraulic oil fills the space in the confining pressure chamber 1 other than the test sample 7, the upper pressure head 21, and the lower pressure head 23, for applying confining pressure to the test sample 7. The pressure gauge 314 can monitor the pressure in the confining pressure chamber 1 in real time. The first solenoid valve 313 can be used to control whether the oil injection pipe 311 is connected to the confining pressure chamber 1. When the first solenoid valve 313 is opened, the oil injection pump 312 connects to the confining pressure chamber 1 through the oil injection pipe 311. The confining pressure chamber 1 is connected, enabling oil injection or pressurization. When the first solenoid valve 313 is closed, the connection between the oil injection pump 312 and the confining pressure chamber 1 is disconnected. The oil drain pipe 321 passes through the confining pressure chamber 1 and connects to the top of the pressurized space. The second solenoid valve 322 is installed on the oil drain pipe 321, which can be used to drain oil from the confining pressure chamber 1. After the test is completed, air can be injected into the oil drain pipe 9, causing the oil in the confining pressure chamber 1 to return to the oil injection pipe 311 under air pressure and be discharged to the oil injection pump 1. The second solenoid valve 322 can control whether the confining pressure chamber 1 is connected to the atmosphere. The first solenoid valve 313, the confining pressure gauge 314, and the second solenoid valve 322 are communicatively connected to the data acquisition and analysis module 6. The data acquisition and analysis module 6 can store and analyze the data monitored by the confining pressure gauge 314 and control the opening or closing of the first solenoid valve 313 and the second solenoid valve 322.

[0034] In some possible implementations, the data acquisition and analysis module 6 includes: several data lines 61; and a computer 62. The computer 62 is connected via the several data lines 61 to the temperature transmitter 515, the gas pressure transmitter 521, the gas solenoid valve 522, the gas flow meter 523, the gas cylinder pressure gauge 422, the gas pump pressure gauge 432, the first solenoid valve 313, the confining pressure gauge 314, and the second solenoid valve 422, respectively. The computer 62 can transmit relevant pressure, temperature, flow rate, and other data monitored by the temperature transmitter 515, gas pressure transmitter 521, gas flow meter 523, gas cylinder pressure gauge 422, gas pump pressure gauge 432, and confining pressure gauge 314 to the computer 62 in real time via the data lines 61. The computer 62 stores the data transmitted via the data lines 61 and analyzes gas flow rate and other data in real time. The computer 62 is also used to control the opening and closing of the gas solenoid valve 522, the first solenoid valve 313, and the second solenoid valve 422.

[0035] Example 2 This second embodiment provides a testing method for a salt rock permeability testing device based on temperature and pressure monitoring, including the following steps: S101 Prepare the test sample 7 and record the basic data related to the experiment; the preparation of the test sample 7 includes: processing the test sample 7 into a standard cylindrical shape by drilling or wire cutting, the test sample 7 is a salt rock sample, the salt rock sample is taken from an underground salt mine; the basic data includes the mass of the test sample 7, the height L of the test sample 7, the inner diameter r of the test sample 7, the cross-sectional area A of the test sample 7, and the volume V of the recovery bottle 513. b And the volume V of the gas collecting pipe 512 and the exhaust pipe 511 L ; S102 The test sample 7 is installed in the pressurized space of the confining pressure chamber 1; the installation of the test sample 7 in the pressurized space of the confining pressure chamber 1 includes: opening the confining pressure chamber 1, connecting the test sample 7 to the upper pressure head 21 and the lower pressure head 23, and installing the test sample 7, the upper pressure head 21, and the lower pressure head 23 as a whole in the confining pressure chamber 1, then connecting the air injection pipe 41 to the upper pressure head 21 and the exhaust pipe 511 to the lower pressure head 23, closing the confining pressure chamber 1 after the connection is completed, and tightly connecting the confining pressure chamber 1 to the confining pressure chamber base 26 with bolts; After S103 is installed, confining pressure is applied to the confining pressure chamber 1 through the confining pressure loading module 3. The application of confining pressure to the confining pressure chamber 1 through the confining pressure loading module 3 includes: opening the first solenoid valve 313 and the second solenoid valve 322, injecting hydraulic oil into the confining pressure chamber 1 through the oil injection pump 312, and closing the second solenoid valve 322 when the hydraulic oil fills the entire confining pressure chamber 1 and flows out from the oil drain pipe 321, and using the oil injection pump 312 to raise the confining pressure in the pressurized space to the confining pressure required for the experiment. S104 sequentially opens the gas solenoid valve 522, closes the gas pump valve 431, and opens the gas cylinder valve 423, inputting the gas from the gas cylinder 421 into the gas injection pump 433. After closing the gas cylinder valve 423, the gas pressure is adjusted to the required experimental pressure P by the gas injection pump 433. up ; After S105 is adjusted, open the air pump valve 431. Gas flows from the air pump 433 into the air injection pipe 41, the test sample 7 and the exhaust pipe 511. After the air pump valve 431 is opened, the air pump 433 needs to be kept open to keep the gas in the air injection pipe 41 constant at the set gas pressure value. After a period of time, observe whether the gas flow meter 523 can detect the gas flow. If the gas flow rate can be detected, the gas flow rate detected by the gas flow meter 523 is recorded at intervals to obtain several sets of gas flow rate values ​​Q; if the gas flow rate cannot be detected, the gas solenoid valve 522 is closed, and the gas flow rate value is calculated at intervals using the low flow monitoring device 51 and the basic data; the gas flow rate value calculated at intervals using the low flow monitoring device 51 and the basic data includes: calculating the amount of gas n0 in the recovery bottle 513, exhaust pipe 511 and gas collecting pipe 512 in the initial stage according to formula (1): (1); In the formula (1), P0 is the pressure inside the recovery bottle 513, exhaust pipe 511, and gas collecting pipe 512 in the initial stage, in MPa; V b For a recycling bottle with a volume of 513, m 3 V L The volume of exhaust pipe 511 and gas collecting pipe 512 is given in m. 3 Z0 is the gas compressibility factor at the initial moment, R is the gas constant, and T0 is the ambient temperature at the initial stage (°C). The gas compressibility factor Z0 at the initial moment can be calculated using the pr gas state equation. Calculate the volume V of the gas under standard conditions in the recovery bottle 513, exhaust pipe 511, and gas collecting pipe 512 at the initial stage according to formula (2). g,0 : (2); In the above formula (2), M is the molar mass of the gas, kg / mol; The density of the gas under standard conditions is kg / m³. 3 ; Open valve 514 of the recycling bottle to allow gas to enter the recycling bottle 513. Record the pressure and ambient temperature of the gas flowing into the recycling bottle 513 at regular intervals, and calculate the amount of gas n in the recycling bottle 513, exhaust pipe 511 and gas collecting pipe 512 at time t according to formula (3). t : (3); In the above formula (3), P t Z represents the pressure inside recovery bottle 513, exhaust pipe 511, and gas collecting pipe 512 at time t, in MPa; t Let T be the gas compressibility factor at time t. t Let be the ambient temperature at time t, in °C; where the gas compressibility factor Z0 at time t can be calculated using the pr gas state equation. Calculate the standard gas volume V in the recovery bottle 513, exhaust pipe 511 and gas collecting pipe 512 at time t according to formula (4). g,t : (4); The gas flow rate Q from the initial stage to time t is calculated according to equation (5): (5); In equation (5), Q is the average flow rate, m 3 / s; t represents time, in seconds; S107 calculates the permeability of the test sample based on each set of gas flow rate values, obtaining several sets of permeability data; the calculation of the permeability of the test sample based on each set of gas flow rate values ​​includes: calculating the permeability k of the test sample based on each set of gas flow rate values ​​Q detected by the gas flow meter or calculated by equation (5) and equation (6): (6); In equation (6), P is atmospheric pressure, MPa; up The pressure monitored by the gas pump pressure gauge is in MPa; P down The pressure monitored by the gas pressure transmitter is MPa; A is the cross-sectional area of ​​the test sample 7, m². 2 L represents the height of the test sample 7, in meters; μ represents the viscosity of the test gas. ; S108 compares the differences between several groups of permeability data, selects permeability data with a permeability change rate of less than 10%, calculates the average permeability, and obtains the measured permeability of the sample to be tested.

[0036] Specifically, this invention provides a testing method for a salt rock permeability testing device based on temperature and pressure monitoring, solving the problem of permeability below 10. -21 m 2 The challenge of permeability testing for salt rock samples, while also possessing the capability to test permeability up to 10... -12 m 2 ~10 -21 m 2 The function of permeability analysis for other rock samples has certain technical practicality and value. It possesses the following beneficial effects: (1) It can perform permeability testing of ultra-low permeability media; (2) The device is simple and convenient to operate and has a high degree of automation.

[0037] It should be noted that the test method of the salt rock permeability test device based on temperature and pressure monitoring provided in this embodiment 2 uses the same salt rock permeability test device as described in this embodiment 1. Its implementation principle and technical concept are exactly the same as those in embodiment 1. Therefore, for the parts not described in detail in this embodiment 2, please refer to embodiment 1. They will not be repeated here.

[0038] Finally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0040] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A salt rock permeability testing device based on temperature and pressure monitoring, characterized in that, include: A confining chamber, wherein the confining chamber has a pressurized space; A fixing module is disposed inside the pressurized space and is used to fix the test sample. A confining pressure loading module, comprising an oil injection component and an oil discharge component, wherein the oil injection component is connected to the bottom of the pressurized space and the oil discharge component is connected to the top of the pressurized space; The gas injection pressure loading module passes through the confining pressure chamber and is connected to the top of the fixed module; A gas flow monitoring module, comprising a low flow monitoring element and a high flow monitoring element, wherein one end of the low flow monitoring element passes through the confining pressure chamber and is connected to the bottom of the fixed module, and the other end of the low flow monitoring element is connected to the high flow monitoring element; The data acquisition and analysis module is communicatively connected to the confining pressure loading module, the gas injection pressure loading module, and the gas flow monitoring module.

2. The salt rock permeability testing device according to claim 1, characterized in that, The fixing module includes: The upper pressure head has a cylindrical structure and is located at the top of the pressurization space. The upper pressure head has a gas inflow channel inside. One end of the gas inflow channel is in contact with the top surface of the sample to be tested, and the other end of the gas inflow channel is connected to the gas injection pressure loading module. The lower pressure head has a cylindrical structure and is located at the bottom of the pressurization space. The test sample is installed between the upper pressure head and the lower pressure head. A gas outflow channel is provided inside the lower pressure head. One end of the gas outflow channel is in contact with the bottom surface of the test sample, and the other end of the gas outflow channel is connected to the low flow monitoring device. A pressure bar is disposed at the top of the confining chamber, and the bottom surface of the pressure bar is in contact with the top surface of the upper pressure head; A confining pressure chamber base is installed at the bottom of the confining pressure chamber and connected to the lower pressure head.

3. The salt rock permeability testing device according to claim 2, characterized in that: The low-flow monitoring device includes an exhaust pipe, a gas collecting pipe, a recovery bottle, a recovery bottle valve, and a temperature transmitter. One end of the exhaust pipe passes through the base of the confining pressure chamber and the bottom of the confining pressure chamber, and is connected to the gas outflow channel. One end of the gas collecting pipe is connected to the middle of the exhaust pipe, and the other end of the gas collecting pipe is connected to the recovery bottle. The recovery bottle valve is installed on the gas collecting pipe, and the temperature transmitter is communicatively connected to the data acquisition and analysis module. The high-flow monitoring device includes a gas pressure transmitter, a gas solenoid valve, and a gas flow meter. The gas pressure transmitter, the gas solenoid valve, and the gas flow meter are arranged adjacent to each other at one end of the exhaust pipe. The gas pressure transmitter, the gas solenoid valve, and the gas flow meter are communicatively connected to the data acquisition and analysis module.

4. The salt rock permeability testing device according to claim 3, characterized in that, The gas injection pressure loading module includes: The gas injection pipe has one end passing through the base of the confining pressure chamber and the bottom of the confining pressure chamber, and is connected to the gas inflow channel. The gas injection device includes a gas cylinder, a gas cylinder pressure gauge, and a gas cylinder valve. The gas cylinder is connected to the other end of the gas injection pipe. The gas cylinder pressure gauge and the gas cylinder valve are arranged adjacent to each other at the other end of the gas injection pipe along the gas inflow channel toward the gas cylinder. The gas cylinder pressure gauge is communicatively connected to the data acquisition and analysis module. The pressure regulating component includes an air pump valve, an air pump pressure gauge, and an air injection pump. The air pump valve, the air pump pressure gauge, and the air injection pump are arranged adjacent to each other on the air injection pipe along the gas inflow channel toward the gas cylinder. The air pump pressure gauge is communicatively connected to the data acquisition and analysis module.

5. The salt rock permeability testing device according to claim 4, characterized in that: The oil injection component includes an oil injection pipe, an oil injection pump, a first solenoid valve, and a confining pressure gauge. One end of the oil injection pipe passes through the confining pressure chamber and is connected to the bottom of the pressurized space. The oil injection pump, the first solenoid valve, and the confining pressure gauge are arranged adjacent to each other on the oil injection pipe along the other end of the oil injection pipe toward one end of the oil injection pipe. The first solenoid valve and the confining pressure gauge are communicatively connected to the data acquisition and analysis module. The oil discharge component includes an oil discharge pipe and a second solenoid valve. The oil discharge pipe passes through the confining pressure chamber and is connected to the top of the pressurized space. The second solenoid valve is mounted on the oil discharge pipe and is communicatively connected to the data acquisition and analysis module.

6. The salt rock permeability testing device according to claim 5, characterized in that, The data acquisition and analysis module includes: Several data lines; The computer is communicatively connected to the temperature transmitter, the gas pressure transmitter, the gas solenoid valve, the gas flow meter, the gas cylinder pressure gauge, the gas pump pressure gauge, the first solenoid valve, the confining pressure gauge, and the second solenoid valve via several data lines.

7. The testing method of the salt rock permeability testing device based on temperature and pressure monitoring as described in any one of claims 1-6, characterized in that, Includes the following steps: Prepare the test samples and record the basic data related to the experiment; The test sample is installed in the pressurized space of the confining pressure chamber; After installation, confining pressure is applied to the confining pressure chamber through the confining pressure loading module; Open the gas solenoid valve in sequence, close the gas pump valve, open the gas cylinder valve, input the gas from the gas cylinder into the gas injection pump, close the gas cylinder valve, and adjust the gas pressure to the required pressure for the experiment using the gas injection pump. After adjustment, open the air pump valve and observe whether the gas flow meter can detect the gas flow after a period of time. If the gas flow rate can be monitored, record the gas flow rate detected by the gas flow meter at regular intervals to obtain several sets of gas flow rate values; if the gas flow rate cannot be monitored, close the gas solenoid valve, and calculate the gas flow rate value at regular intervals using the low flow monitoring device and the aforementioned basic data. The permeability of the sample to be tested is calculated based on the gas flow rate value of each group, resulting in several sets of permeability data; By comparing the differences among several sets of permeability data, the permeability data with a permeability change rate of less than 10% are selected to calculate the average permeability, thus obtaining the measured permeability of the sample to be tested.

8. The test method according to claim 7, characterized in that, The gas flow rate values ​​calculated at regular intervals using the low-flow monitoring device and the aforementioned basic data include: The amount of gas n0 in the recovery bottle, exhaust pipe, and gas collecting pipe during the initial stage is calculated according to formula (1): （1）； In equation (1), P0 is the pressure inside the recovery bottle, exhaust pipe, and gas collecting pipe in the initial stage, and V b V is the volume of the recycled bottle. L Let Z0 be the volume of the exhaust pipe and the gas collection pipe, Z0 be the gas compressibility factor at the initial moment, R be the gas constant, and T0 be the ambient temperature at the initial stage. Calculate the volume V of gas under standard conditions in the recovery bottle, exhaust pipe, and gas collecting pipe during the initial stage according to formula (2). g,0 : （2）； In equation (2), M is the molar mass of the gas. This refers to the gas density under standard conditions. Open the valve of the recovery bottle to allow gas to enter the recovery bottle. Calculate the amount of gas, n, in the recovery bottle, exhaust pipe, and gas collecting pipe at time t according to equation (3) at regular intervals. t : （3）； In the above formula (3), P t Let Z be the pressure inside the recovery bottle, exhaust pipe, and gas collection pipe at time t. t Let T be the gas compressibility factor at time t. t Let t be the ambient temperature at time t; Calculate the standard gas volume V in the recovery bottle, exhaust pipe, and gas collecting pipe at time t according to equation (4). g,t : （4）； The gas flow rate Q from the initial stage to time t is calculated according to equation (5): （5）。 9. The test method according to claim 8, characterized in that, The permeability of the test sample is calculated based on the gas flow rate values ​​for each group, including: Calculate the permeability k of the sample to be tested based on the gas flow rate Q of each group and equation (6): （6）； In equation (6), P is atmospheric pressure, P up The pressure monitored by the gas pump pressure gauge, P down The pressure is monitored by the gas pressure transmitter, A is the cross-sectional area of ​​the test sample, L is the height of the test sample, and μ is the viscosity of the test gas.

10. The test method according to claim 9, characterized in that: The basic data includes the mass of the test sample, the height of the test sample, the inner diameter of the test sample, the cross-sectional area of ​​the test sample, the volume of the recovery bottle, and the volume of the exhaust pipe and the gas collection pipe. The step of installing the test sample in the pressurized space of the confining pressure chamber includes: opening the confining pressure chamber, connecting the test sample to the upper pressure head and the lower pressure head, and installing the test sample and the upper and lower pressure heads as a whole in the confining pressure chamber, then connecting the air injection pipe to the upper pressure head and the exhaust pipe to the lower pressure head, closing the confining pressure chamber after the connection is completed, and tightly connecting the confining pressure chamber to the confining pressure chamber base with bolts. The process of applying confining pressure to the confining pressure chamber via the confining pressure loading module includes: opening the first solenoid valve and the second solenoid valve, injecting hydraulic oil into the confining pressure chamber via an oil injection pump, and closing the second solenoid valve when the hydraulic oil fills the entire confining pressure chamber and flows out from the oil drain pipe, and using the oil injection pump to raise the confining pressure in the pressurized space to the confining pressure required for the experiment.

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