An experimental device and method for evaluating sensitivity of terrestrial shale

Abstract

The utility model relates to a kind of experimental device and method for evaluating terrestrial shale sensitivity, it is related to shale experimental equipment technical field. Including axial pressure system, displacement system, holder, the axial pressure system is used to output pressure medium, and pressure output end is sealed with the axial pressure medium import of holder Connection, the displacement system is used to transport the saturated medium of core module, and pressure output end is sealed with the input end of liquid inlet pipe Connection, the liquid outlet pipe of holder is connected with liquid storage container by first valve door. The present application solves the problem that shale reservoir is difficult to displace with low porosity and low permeability on one hand, on the other hand, it can avoid the closure of internal bedding seam of shale due to external force, ensure integrity, realize the effective development of displacement experiment, also provide accurate guidance for the development of field development plan.

Description

Technical Field

[0001] This invention relates to the field of shale experimental equipment technology, specifically to an experimental apparatus and method for evaluating the sensitivity of terrestrial shale. Background Technology

[0002] In recent years, China has made breakthrough progress in the exploration of continental shale oil. In the early stages of extraction, the formation energy is abundant and the production is high. However, as time goes on, the water cut continues to rise. Hydraulic fracturing has not been effective in reducing water cut; instead, it has further reduced production, and development problems have gradually emerged. Sensitivity, as one of the important parameters for reservoir stimulation, can provide important guidance for the selection of displacement fluids for secondary extraction. However, shale oil reservoirs are low in porosity and permeability, making displacement difficult. To solve this problem, a percolation + experimental testing technique was proposed. Combining nuclear magnetic resonance (NMR) experiments with saturated formation water, it was found that during natural percolation, the increase in movable fluid is about 30%; under pressurized percolation experimental conditions, the increase in movable fluid is about 60%, an increase of 2 times, indicating that continuous pressure extraction can effectively improve development results.

[0003] Based on effective permeation experimental techniques, sensitivity damage assessment experiments were conducted on the samples. It was found that the shale samples after permeation can not only be displaced, but also the sensitivity parameters can be evaluated through changes in permeability.

[0004] However, compared to the porous structure of sandstone, the fluid channels within shale are mainly pores and fractures. Due to the well-developed bedding fractures in shale reservoirs, traditional sensitivity assessment methods, such as displacement processes, impose confining pressures on the core radially exceeding the displacement pressure by 1.5–2 MPa. This process leads to the closure of bedding fractures within the shale reservoir. Bedding fractures, as important storage spaces within shale, are a crucial part of sensitivity assessment; closure not only leads to experimental failure but also renders the sensitivity assessment parameters invalid. Therefore, a passive confining pressure core holder has been invented, which can effectively protect the pore and fracture structure within the core and effectively conduct shale sensitivity assessment. Summary of the Invention

[0005] One objective of this invention is to provide an experimental apparatus for evaluating the sensitivity of continental shale, which can effectively protect the internal pore structure of the core, thereby enabling effective evaluation of shale sensitivity.

[0006] The technical solution to achieve the above objective is: an experimental device for evaluating the sensitivity of continental shale, characterized in that: it includes an axial compression system, a displacement system, and a clamp, the clamp including a cylinder, a core chamber for accommodating a core module is provided in the middle of the cylinder, a hollow cavity matching the diameter of the core module is provided in the core chamber, a centralizing ring is provided at both ends of the core chamber, and an inner pressure cap is threaded to both ends of the cylinder, the centralizing ring being positioned and pressed between the core chamber and the inner pressure cap;

[0007] A perforated piston and a cylindrical pad are sequentially attached to both ends of the core module. The perforated piston and the cylindrical pad are slidably disposed between the core chamber and the corresponding straightening ring. A sealing ring with an outer diameter matching the inner diameter of the core chamber is provided between the perforated piston and the core module. The sealing ring has a central hole.

[0008] One side of the inner pressure cap has an outer port threadedly connected to an outer pressure cap that presses inward against a cylindrical pad on the same side, and the other side of the inner pressure cap has an outer port threadedly connected to an axial pressure piston that presses inward against a cylindrical pad on the same side. The outer sealing sleeve of the axial pressure piston is fitted with an axial pressure cylinder that seals and fits tightly against the inner pressure cap on the same side. A closed piston cavity is formed between the axial pressure cylinder, the axial pressure piston on the same side, and the inner pressure cap. An axial pressure medium inlet is provided on the axial pressure cylinder, and the axial pressure medium inlet communicates with the piston cavity through a medium channel provided in the side wall of the axial pressure cylinder.

[0009] The two perforated pistons on both sides are respectively provided with a central through hole. The central through hole of the perforated piston on the same side as the outer pressure cap is sealed and connected to the liquid inlet pipe. The liquid inlet pipe passes outward through the cylindrical pad on the same side and extends outward from the outer pressure cap. The central through hole of the perforated piston on the other side is sealed and connected to the liquid outlet pipe. The liquid outlet pipe passes outward through the cylindrical pad on the same side and extends outward from the axial pressure piston.

[0010] The axial pressure system is used to output pressure medium, and the pressure output end is sealed to the axial pressure medium inlet of the clamp. The displacement system is used to output saturated medium from the core module, and the pressure output end is sealed to the input end of the liquid inlet pipe. The liquid outlet pipe of the clamp is connected to a liquid storage container through a first valve.

[0011] Furthermore, the axial pressure system includes a medium storage container, an axial pressure flow pump, and a second valve connected in series, with the output end of the second valve connected to the axial pressure medium inlet of the clamp.

[0012] Furthermore, the working medium in the medium storage container is distilled water.

[0013] Furthermore, the displacement system includes a formation water storage container and a displacement flow pump connected in sequence, with the output end of the displacement flow pump connected to the inlet pipe.

[0014] Furthermore, an intermediate container is connected in series between the output end of the displacement flow pump and the inlet pipe, and a third valve is connected in series between the displacement flow pump and the intermediate container, and between the intermediate container and the inlet pipe. Furthermore, the cylindrical pads on both sides are fitted with the perforated pistons on the corresponding sides, and the centralizing rings on both sides are fitted with the same side ends of the core chamber through stop joints.

[0015] Furthermore, an annular pad is provided between the outer pressure cap and the cylindrical pad on the same side, and the annular pad and the cylindrical pad on the same side are fitted by a stop joint, and the axial pressure piston and the cylindrical pad on the same side are fitted by a stop joint.

[0016] Another object of the present invention is to provide an experimental method for evaluating the sensitivity of terrestrial shale to terrestrial shale, characterized by comprising the following steps:

[0017] 1) The core sample was saturated by simulated formation water absorption;

[0018] 2) After the core is saturated with permeation, the core is wrapped with epoxy resin to form a core module. The core module is polished and ground to make the diameter of the core module match the inner diameter of the core. At the same time, the two ends of the core module are cut to make the epoxy resin of the core module and the two end faces of the core flush.

[0019] 3) Loosen the outer pressure cap, and take out the annular pad, cylindrical pad, perforated piston, and sealing ring on the same side as the outer pressure cap in sequence. Then put the core module into the core chamber, and then put the removed sealing ring, perforated piston, cylindrical pad, and annular pad back into the cylinder in sequence. Finally, tighten the outer pressure cap so that the core module is clamped between the perforated pistons on both sides.

[0020] 4) Open the second valve and start the axial pressure flow pump. Distilled water in the medium storage container enters the piston chamber to form axial pressure. The axial pressure pushes the axial pressure piston, the cylindrical pad and the perforated piston on the same side to move inward, causing the sealing rings on both sides of the core module to be squeezed and deformed, thus achieving a seal between the core module and the outer periphery of the perforated piston end. At the same time, the central through hole of the perforated piston at both ends is connected to the hole in the core through the central hole of the sealing ring.

[0021] 5) Open the first valve and the third valve, start the displacement flow pump, and conduct the displacement experiment.

[0022] Furthermore, the core bedding direction in the core module is set along the axial direction of the core module; the magnitude of the axial pressure in step 4) is 0.5~1 MPa;

[0023] The specific process of the displacement experiment in step 5) is as follows: a. Start displacement at a flow rate of 0.05 ml / min, keep the displacement pressure lower than the axial pressure until the liquid outlet pipe starts to discharge liquid. When the liquid outlet flow rate is consistent with the liquid inlet flow rate, record the flow rate of the displacement pump and the pressure of the displacement pump, and calculate the core permeability.

[0024] b. Displacement experiments were conducted on the displacement flow pump at output flow rates of 0.1 ml / min, 0.15 ml / min, 0.2 ml / min, 0.25 ml / min, 0.3 ml / min and 0.4 ml / min respectively, and the displacement pressure was recorded under the stable flow rate condition.

[0025] Furthermore, the specific treatment steps for saturation by percolation in step 1) are as follows:

[0026] 1) The core samples were treated with salt and oil washing;

[0027] 2) The core was dried, then weighed, its length and diameter were measured, and nuclear magnetic resonance (NMR) tests were performed to obtain the signal data obtained from the NMR.

[0028] 3) Repeat step 2) and compare the two adjacent MRI data. If there is a change, proceed to step 2); if there is no change, proceed to step 4).

[0029] 4) Place the core and simulated formation water in different containers, and seal the two containers together with a hose to make the two containers connected. Then, evacuate both containers simultaneously.

[0030] 5) After vacuuming is completed, simulated formation water is poured into a container containing the core under vacuum conditions and saturated at normal pressure.

[0031] 6) Every 30-40 minutes, the core is removed from the container for weighing and nuclear magnetic resonance testing. Once the weighing data on adjacent sides are the same, the core enters the self-absorption state.

[0032] 7) After entering the self-absorption state, test the NMR signal once every other day;

[0033] 8) Compare the nuclear magnetic resonance data of two adjacent core samples after the self-absorption state. If there is a change, proceed to step 7); if there is no change, proceed to step 9.

[0034] 9) The core was subjected to high pressure and high temperature saturation, with the pressure and temperature matching those of the formation where the core was located. The nuclear magnetic resonance signal was tested once a week.

[0035] 10) Compare the nuclear magnetic resonance data of two adjacent core samples. If there is a change, proceed to step 9). If there is no change, the permeation saturation is completed.

[0036] The beneficial effects of this invention are: on the one hand, this invention solves the problem of low porosity and low permeability of shale reservoirs making them difficult to displace; on the other hand, it can effectively improve the problem of strong stress sensitivity of shale in traditional displacement processes.

[0037] In existing technologies, as displacement pressure increases, continuously applying confining pressure to the core through artificial means can induce strong stress sensitivity in shale, making it impossible to accurately assess the sensitivity. This invention employs a passive confining pressure displacement device, aligning the core bedding direction within the clamp along the axial direction of the core module. By applying axial pressure of 0.5~1 MPa to both ends of the core module, a seal is achieved at both ends. The relatively low axial pressure prevents closure of internal bedding fractures within the core module. Furthermore, the pressure is distributed through an outer epoxy resin layer, making the pressure applied to both ends of the core negligible. This completely avoids closure of internal bedding fractures in the shale due to external forces, ensuring integrity. Experimental displacement tests can be effectively conducted, providing precise guidance for the formulation of on-site development plans. Attached Figure Description

[0038] Figure 1 This is a system schematic diagram of the present invention;

[0039] Figure 2 This is a schematic diagram of the clamping device.

[0040] Figure 3 The images show the nuclear magnetic resonance spectra before and after conventional displacement under confining pressure.

[0041] Figure 4 The nuclear magnetic resonance spectra before and after displacement using the present invention are shown. Detailed Implementation

[0042] like Figure 1 , 2 As shown, this invention discloses an experimental apparatus for evaluating the sensitivity of continental shale, including an axial compression system 1, a displacement system 2, and a clamp 3. The clamp 3 includes a horizontally arranged cylinder 3.1. A core chamber 3.2 for accommodating a core module 7 is provided in the middle of the cylinder 3.1. A hollow cavity 3.3 matching the diameter of the core module 7 is provided in the core chamber 3.2. A centralizing ring 3.4 is provided at both ends of the core chamber 3.2. The centralizing ring 3.4 and the core chamber 3.2 are respectively fitted with a stop. Preferably, the inner diameter of the core chamber 3.2 and the centralizing ring 3.4 are the same. An inner pressure cap 3.5 is threaded to both ends of the cylinder 3.1. The centralizing ring 3.4 is positioned and pressed between the core chamber 3.2 and the inner pressure cap 3.5.

[0043] A cylindrical pad 3.16 is slidably fitted inside the straightening ring 3.4. A perforated piston 3.6 is slidably installed between the cylindrical pad 3.16 and the core module 4. A sealing ring 3.7 with an outer diameter matching the inner diameter of the core chamber 3.2 is installed between the perforated piston 3.6 and the core module 4. The sealing ring 3.7 has a central hole.

[0044] The outer port of the left inner pressure cap 3.5 is threadedly connected to an outer pressure cap 3.8 that presses inward against the cylindrical pad 3.16 on the same side. The outer port of the right inner pressure cap 3.5 is threadedly connected to an axial pressure piston 3.9 that presses inward against the cylindrical pad 3.16 on the same side. An annular pad 3.17 is provided between the outer pressure cap 3.8 and the cylindrical pad 3.16 on the same side. The annular pad 3.17 and the cylindrical pad 3.16 on the left side, and the axial pressure piston 3.9 and the cylindrical pad 3.16 on the right side, are respectively fitted by a stop.

[0045] The axial pressure piston 3.9 is covered with an axial pressure cylinder 3.10 on its outer sealing sleeve. The axial pressure cylinder 3.10 is also sealed to the inner pressure cap 3.5. A closed piston cavity 3.11 is formed between the axial pressure cylinder 3.10, the axial pressure piston 3.9 and the inner pressure cap 3.5 on the same side. An axial pressure medium inlet 3.12 is provided on the axial pressure cylinder 3.10. The axial pressure medium inlet 3.12 is connected to the piston cavity 3.11 through a medium channel 3.13 provided in the side wall of the axial pressure cylinder 3.10.

[0046] Both perforated pistons 3.6 have central through holes. The central through hole of the left perforated piston 3.6 is sealed to the inlet pipe 3.14. The inlet pipe 3.14 passes outward through the cylindrical pad 3.16 on the left and extends outward to the outer pressure cap 3.8. The central through hole of the right perforated piston 3.6 is sealed to the outlet pipe 3.15. The outlet pipe 3.15 passes to the right through the cylindrical pad 3.16 on the same side and extends outward to the axial pressure piston 3.9.

[0047] The axial pressure system includes a medium storage container 1.1, an axial pressure flow pump 1.2, and a second valve 1.3 connected in series. The output end of the second valve 1.2 is connected to the axial pressure medium inlet 3.12 of the clamp 3. The working medium in the medium storage container 1.1 is distilled water.

[0048] The displacement system 2 includes a formation water storage container 2.1 and a displacement flow pump 2.2 connected in sequence. The output end of the displacement flow pump 2.2 is connected to the inlet pipe 3.14. An intermediate container 2.3 is also connected in series between the output end of the displacement flow pump 2.2 and the inlet pipe 3.14. A third valve 2.4 is connected in series between the displacement flow pump 2.2 and the intermediate container 2.3, and between the intermediate container 2.3 and the inlet pipe 3.14. The outlet pipe 3.15 of the clamp 3 is connected to the storage container 5 through the first valve 4. The storage container 5 is supported on the weighing device 6.

[0049] The experimental method for evaluating the sensitivity of terrestrial shale using the above-mentioned experimental apparatus is characterized by comprising the following steps:

[0050] 1) The core sample was saturated by simulated formation water absorption;

[0051] 2) After the core is saturated with permeation and wrapped with epoxy resin to form core module 7, the core module 7 is polished and ground to match the diameter of the core module 7 with the inner diameter of the core chamber 3.2. At the same time, the two ends of the core module 7 are cut to make the two end faces of the epoxy resin 7.1 and the core 7.2 flush.

[0052] 3) Loosen the outer pressure cap 3.8, and take out the annular pad 3.17, cylindrical pad 3.16, perforated piston 3.6, and sealing ring 3.7 on the same side as the outer pressure cap in sequence. Then put the core module 7 into the core chamber, and then put the removed sealing ring 3.7, perforated piston 3.6, cylindrical pad 3.16, and annular pad 3.17 back into the cylinder 3.1 in sequence. Finally, tighten the outer pressure cap 3.8 so that the core module 7 is clamped between the perforated pistons 3.6 on both sides.

[0053] 4) Open the second valve 1.3 and start the axial pressure flow pump 1.2. The distilled water in the medium storage container 1.1 enters the piston chamber 3.11 to form axial pressure. The axial pressure is 0.5~1 MPa. The axial pressure pushes the axial pressure piston 3.9 and the cylindrical pad 3.16 and the perforated piston 3.6 on the same side to move inward, so that the sealing rings 3.7 on both sides of the core module 7 are squeezed and deformed, so as to achieve the seal between the core module 7 and the outer periphery of the end of the perforated piston 3.6. At the same time, the central through hole of the perforated pistons 3.6 at both ends is connected to the hole in the core 7.2 through the central hole of the sealing ring 3.7.

[0054] 4) Open the first valve 4 and the third valve 2.4, and start the displacement flow pump 2.2 at a flow rate of 0.05 ml / min. Keep the displacement pressure lower than the axial pressure until liquid starts to flow from the outlet pipe 3.15. When the liquid flow rate of the outlet pipe 3.15 is the same as the liquid flow rate of the inlet pipe, record the flow rate and pressure of the displacement flow pump 2.2, and calculate the core permeability.

[0055] 5) Control the displacement flow rate of pump 2.2 and conduct displacement experiments at output flow rates of 0.1 ml / min, 0.15 ml / min, 0.2 ml / min, 0.25 ml / min, 0.3 ml / min and 0.4 ml / min respectively, and record the displacement pressure under the stable flow rate condition.

[0056] As a further illustration of this embodiment, the epoxy resin coating of the core is a mature existing technology, and its specific process steps will not be described in detail.

[0057] Furthermore, the specific treatment steps for saturation by percolation in step 1) are as follows:

[0058] 1) The core samples were treated with salt and oil washing;

[0059] 2) The core was dried at 60℃ for 16 hours, then weighed, its length and diameter were measured, and nuclear magnetic resonance (NMR) tests were performed to obtain the signal data obtained from the NMR.

[0060] 3) Repeat step 2) and compare the data from two adjacent NMR studies. If there is a change, proceed to step 2); if there is no change, proceed to step 4).

[0061] 4) Place the core and simulated formation water in different containers, and seal the two containers together with a hose to make the two containers connected. Then, evacuate both containers simultaneously.

[0062] 5) After vacuuming is completed, simulated formation water is poured into a container containing the core under vacuum conditions and saturated at normal pressure.

[0063] 6) Every 30-40 minutes, the core is removed from the container for weighing and nuclear magnetic resonance testing. Once the weighing data on adjacent sides are the same, the core enters the self-absorption state.

[0064] 7) After entering the self-absorption state, test the NMR signal once every other day;

[0065] 8) Compare the nuclear magnetic resonance data of two adjacent core samples after the self-absorption state. If there is a change, proceed to step 7); if there is no change, proceed to step 9.

[0066] 9) The core was subjected to high pressure and high temperature saturation, with the pressure and temperature being consistent with the pressure and temperature of the formation where the core was located. The nuclear magnetic resonance signal was tested once a week.

[0067] 10) Compare the nuclear magnetic resonance data of two adjacent core samples. If there is a change, proceed to step 9). If there is no change, the permeation saturation is completed.

[0068] Using this invention, a comparative experiment was conducted on two core samples from the same stratum, and the results are as follows:

[0069] Figure 3 The images show the nuclear magnetic resonance spectra before and after conventional displacement under confining pressure. Figure 4 The images shown are the nuclear magnetic resonance spectra before and after displacement according to this invention. Figure 3 , 4 The nuclear magnetic resonance spectrum results show that the internal pore space of the core decreases sharply before and after traditional confining pressure displacement, while the internal pore space of the core remains basically unchanged before and after displacement using the device and method of this invention. This indicates that for shale reservoirs, the traditional confining pressure method causes significant damage to the core and cannot effectively achieve shale sensitivity evaluation.

Claims

1. An experimental apparatus for evaluating the sensitivity of a continental shale, characterized by: The core module is formed by wrapping an epoxy resin outside a saturated core, and a hollow cavity matching the diameter of the core module is arranged in the core chamber, and a centralizing ring is arranged at both ends of the core chamber, and an internal pressure cap is threadedly connected to both ends of the cylinder, and the centralizing ring is positioned and compressed between the core chamber and the internal pressure cap. The two ends of the core module are sequentially attached with a hole piston and a cylindrical pad, and the hole piston and the cylindrical pad are slidingly arranged between the core chamber and the corresponding side centralizing ring, and a sealing ring with an outer diameter matching the inner diameter of the core chamber is arranged between the hole piston and the core module. The outer port of one side of the internal pressure cap is threadedly connected with an external pressure cap that is pressed inward to the same side cylindrical pad, and the outer port of the other side of the internal pressure cap is threadedly connected with an axial pressure piston that is pressed inward to the same side cylindrical pad, and an axial pressure cylinder is arranged on the outer sealing sleeve of the axial pressure piston and is sealingly attached to the same side internal pressure cap, and a closed piston cavity is formed between the axial pressure cylinder, the same side axial pressure piston and the internal pressure cap, and an axial pressure medium inlet is arranged on the axial pressure cylinder, and the axial pressure medium inlet is communicated with the piston cavity through a medium channel arranged in the side wall of the axial pressure cylinder. The center of the hole piston on both sides is provided with a central through hole, and the central through hole of the hole piston on the same side of the external pressure cap is sealingly connected with a liquid inlet pipe, and the liquid inlet pipe penetrates outward through the same side cylindrical pad and extends out of the external pressure cap, and the central through hole of the hole piston on the other side is sealingly connected with a liquid outlet pipe, and the liquid outlet pipe penetrates outward through the same side cylindrical pad and extends out of the axial pressure piston. The axial pressure system is used to output pressure medium, and the pressure output end is sealingly connected with the axial pressure medium inlet of the holder, the displacement system is used to output the saturated medium of the core module, and the pressure output end is sealingly connected with the input end of the liquid inlet pipe, and the liquid outlet pipe of the holder is connected with a liquid storage container through a first valve. The core layering direction in the holder is arranged along the axial direction of the core module, and the sealing of the two ends of the core is realized by applying an axial pressure of 0.5-1mpa at both ends of the core module.

2. The experimental device for evaluating the sensitivity of a continental shale according to claim 1, characterized in that: The axial pressure system comprises a medium storage container, an axial pressure flow pump and a second valve connected in series.

3. The experimental device for evaluating the sensitivity of a continental shale according to claim 2, characterized in that: The working medium in the medium storage container is distilled water.

4. The experimental device for evaluating the sensitivity of a continental shale according to claim 3, characterized in that: The displacement system comprises a formation water storage container and a displacement flow pump connected in series, and the output end of the displacement flow pump is connected with the liquid inlet pipe.

5. The experimental device for evaluating the sensitivity of a continental shale according to claim 4, characterized in that: An intermediate container is further connected between the output end of the displacement flow pump and the liquid inlet pipe, and a third valve is connected between the displacement flow pump and the intermediate container and between the intermediate container and the liquid inlet pipe.

6. The experimental device for evaluating the sensitivity of a continental shale according to claim 1, characterized in that: The two cylindrical pads and the corresponding hole pistons, and the two centralizing rings and the same side ends of the core chamber are all connected through a stop port.

7. The experimental device for evaluating the sensitivity of a continental shale according to claim 1, characterized in that: An annular pad is arranged between the external pressure cap and the same side cylindrical pad, and the annular pad and the same side cylindrical pad are connected through a stop port, and the axial pressure piston and the same side cylindrical pad are connected through a stop port.

8. The experimental method of evaluating the sensitivity of a continental shale using an experimental device of claim 5, wherein, The method comprises the following steps: 1) Saturate the core by simulating formation water. 2) After the core is saturated by imbibition, the core module is formed by wrapping the core with epoxy resin, and the core module is polished to match the diameter of the core module with the inner diameter of the core chamber. Meanwhile, the two ends of the core module are cut to make the epoxy resin and the two end faces of the core flush; 3) Loosen the outer pressure cap, and sequentially remove the annular pad, cylindrical pad, piston with hole, and sealing ring on the same side of the outer pressure cap. Then, the core module is loaded into the core chamber. The removed sealing ring, piston with hole, cylindrical pad, and annular pad are sequentially reloaded into the cylinder. Finally, the outer pressure cap is tightened to clamp the core module between the two pistons with hole; 4) Open the second valve and start the axial pressure flow pump. The distilled water in the medium storage container enters the piston cavity to form an axial pressure. The axial pressure pushes the axial piston and the cylindrical pad and piston with hole on the same side to move inward, causing the sealing rings on both sides of the core module to deform and seal the space between the core module and the outer periphery of the end of the piston with hole. Meanwhile, the central through hole of the piston with hole on both ends communicates with the hole in the core through the central hole of the sealing ring; 5) Open the first valve and the third valve, and start the displacement flow pump to perform displacement experiment.

9. The experimental method of evaluating the sensitivity of a continental shale according to claim 8, wherein: The core in the core module is arranged in the axial direction of the core module. In step 4), the axial pressure is 0.5-1mpa; In step 5), the specific process of the displacement experiment is as follows: a. Start displacement at a flow rate of 0.05ml / min, keep the displacement pressure lower than the axial pressure, until the liquid outlet pipe starts to discharge liquid. When the liquid flow rate of the liquid outlet pipe is consistent with the liquid flow rate of the liquid inlet pipe, record the flow rate of the displacement flow pump and the pressure of the displacement pump, and calculate the core permeability; b. The displacement flow pump is sequentially operated at output flow rates of 0.1ml / min, 0.15ml / min, 0.2ml / min, 0.25ml / min, 0.3ml / min, and 0.4ml / min to perform displacement experiments, respectively. The displacement pressure under stable conditions at each flow rate is recorded.

10. The experimental method of the experimental device for evaluating the sensitivity of continental shale according to claim 7, characterized in that: In step 1), the specific treatment steps for imbibition saturation are as follows: 1) Wash the core with salt and oil; 2) Dry the core, then weigh it, measure its length and diameter, and perform nuclear magnetic resonance test to obtain the signal data measured by nuclear magnetic resonance; 3) Repeat step 2), and compare the nuclear magnetic resonance data of the two adjacent times. If there is a change, go to step 2). If there is no change, go to step 4); 4) Place the core and simulated formation water in different containers, and connect the two containers by a hose to make them communicate. Then, vacuumize the two containers simultaneously; 5) After vacuumization, pour the simulated formation water into the container containing the core under vacuum condition to achieve normal pressure saturation; 6) Every 30-40 minutes, take out the core from the container to weigh it and perform nuclear magnetic resonance test once. After the weight data of the two adjacent sides are the same, the core enters the imbibition state; 7) After entering the imbibition state, test the nuclear magnetic signal once every day. ​ 8) compare the two adjacent core NMR data after self-saturation, if there is a change, go to step 7), if there is no change, go to step 9); 9) saturate the core at high pressure and high temperature, the pressure and temperature are consistent with the formation pressure and temperature where the core is located, test the NMR signal every other week; 10) compare the two adjacent core NMR data, if there is a change, go to step 9), if there is no change, complete the imbibition saturation.

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