A dynamic simulation system for pre-fracture fluid performance in thick and hard critical layers

Abstract

The present application discloses a dynamic simulation system for the performance of pre-fracture fracturing fluid in thick and hard critical layers, and relates to the technical field of fracturing fluid performance simulation. The present application includes a clamp body, one end of the clamp body is fixedly connected to a base plate, the other end of the outer wall of the clamp body is fixedly connected to a fixed plate, and a core plug is installed on one side of the fixed plate. The present application is provided with a clamping assembly, and when the core sample is placed inside the clamp body, a high-pressure air pump is used to pressurize the inside of the fixed block through the air inlet, so that the two clamps can be pushed to fit the core sample through the sealing plate, and the sealing air cushion can be inflated through the air pipe at the same time, so that the clamp body can firmly hold the core sample inside the clamp body, greatly improving the stability and sealing of the core sample inside the clamp body, so that the clamp body can adapt to the different sizes of different core samples, and improve the flexibility and breadth of the experiment.

Description

Technical Field

[0001] The present application relates to the technical field of fracturing fluid performance simulation, and in particular to a dynamic simulation system for pre-fracture fracturing fluid performance in thick and hard critical layers. Background Art

[0002] Fracturing fluid refers to a heterogeneous and unstable chemical system formed by a variety of additives in a certain ratio. Its main function is to transfer the high pressure generated by ground equipment to the formation, causing the formation to break and form cracks and transport proppant along the cracks. In daily simulation of real formation conditions, dynamic simulation of the performance of fracturing fluid for pre-fracture of thick and hard key layers is generally used to evaluate the performance of fracturing fluid under high pressure and high temperature environment.

[0003] In the coal mining field, hydraulic measures represented by hydraulic fracturing are widely used to increase coal seam permeability. Optimizing hydraulic fracturing parameters is the key to achieving ideal economic benefits, involving multiple dimensions such as fracturing section design parameters and construction parameters. Therefore, a dynamic simulation system can help researchers and engineers intelligently find the best matching set of fracturing parameters to improve fracturing efficiency and effectiveness. Existing simulation systems usually contain a series of sophisticated equipment, such as core holders, presses, constant temperature boxes, constant speed and constant pressure pumps, intermediate containers, and various valves. Among them, the role of the holder is particularly critical. It not only needs to fix the core sample, but also ensures the sealing during high-pressure experiments to ensure the accuracy and safety of the experiment.

[0004] However, when using a traditional core holder, the core sample is usually simply stuffed into the holder. This practice often leads to insufficient stability and sealing of the holder for the core sample. In addition, due to the different sizes of different core samples, traditional holders are difficult to adapt to cores of various specifications, which limits the flexibility and breadth of the experiment. For this reason, the present application provides a dynamic simulation system for the performance of pre-fracture fracturing fluid in thick and hard critical layers. Summary of the Invention

[0005] The purpose of this application is to solve the problem that the stability and sealing of the clamp on the core sample are insufficient, which limits the flexibility and breadth of the experiment. This application provides a dynamic simulation system for the performance of pre-fracture fracturing fluid in thick and hard critical layers.

[0006] In order to achieve the above-mentioned purpose, this application specifically adopts the following technical solutions:

[0007] A dynamic simulation system for the performance of pre-fracture fracturing fluid in thick and hard critical layers, comprising a clamp body, one end of the clamp body being fixedly connected to a base plate, the other end outer wall of the clamp body being fixedly connected to a fixing plate, a core plug being installed on one side of the fixing plate, a plurality of nuts being symmetrically threadedly connected to one side of the core plug, and the plurality of nuts being threadably connected to one side of the fixing plate, a liquid inlet being fixedly connected to the clamp body, a liquid outlet being fixedly connected to the clamp body, one end of each of the liquid inlet and the liquid outlet being fixedly connected to a solenoid valve, fixed blocks being symmetrically fixedly connected to both sides of the clamp body, a clamping assembly being installed inside the fixed block, and a sealing air cushion being fixedly connected inside the clamp body.

[0008] By adopting the above technical solution, the core sample is inserted into the interior of the clamp body. At this time, the fixing plate and the core plug can be fitted together. By screwing multiple nuts in reverse, one end of the clamp body can be sealed through the core plug. After the core sample is placed in the interior of the clamp body, the clamping assembly inside the fixing block can be started to operate. The operation of the clamping assembly can securely hold core samples of different sizes in the interior of the clamp body. At the same time, when the clamping assembly is operating, the sealing air cushion can also be inflated, thereby greatly improving the stability and sealing of the core sample inside the clamp body. At the same time, the clamping assembly can also adapt to the different sizes of core samples, thereby improving the flexibility and breadth of the experiment.

[0009] Furthermore, the clamping assembly includes an air inlet fixedly connected to one side of the two fixed blocks, one end of the air inlet is fixedly connected to solenoid valve 2, one side of the two fixed blocks is fixedly connected with an air supply pipe, the ends of the two air supply pipes away from the fixed blocks are fixedly connected to the sealing air cushion, the interior of the two fixed blocks is slidably connected with a sealing plate, and a clip is provided on one side of the sealing plate.

[0010] By adopting the above technical solution, a high-pressure air pump is used to inflate the interior of the fixed block through the air inlet. At this time, the impact force of the air pump will push the sealing plate to move inside the fixed block, so that the sealing plate is gradually separated from one end of the air pipe. At this time, the gas will gradually enter the interior of the sealing air cushion through the air pipe, causing the sealing air cushion to gradually inflate and expand.

[0011] Furthermore, a connecting column is fixedly connected to one side of the sealing plate, the connecting column penetrates and is slidably connected to the inside of the clamp body, and an end of the connecting column away from the sealing plate is fixedly connected to a clamping plate.

[0012] By adopting the above technical solution, the two connecting columns are used to push the two clamps closer to each other inside the clamp body, so that the two clamps fit the core sample. In this way, the clamp body can adapt to the different sizes of different core samples, thereby improving the flexibility and breadth of the experiment.

[0013] Furthermore, the inner walls of the two clamping plates are fixedly connected with rubber pads, the side of the sealing plate away from the connecting column is fixedly connected with spring 1, and the end of the spring 1 away from the sealing plate is fixedly connected to the inner wall side of the fixed block.

[0014] By adopting the above technical solution, the friction between the clamping plate and the core sample can be increased by setting the rubber pad, thereby improving the clamping stability. After the pressure inside the fixed block is released, the sealing plate can be pulled to reset through one side of the spring.

[0015] Furthermore, the clamping member includes a connecting block fixedly connected to one side of the sealing plate, a groove is provided on one side of the connecting block, a spring 2 is fixedly connected inside the groove, a clamping block is slidably connected inside the groove, one end of the spring 2 is fixedly connected to one end of the groove, and a plurality of clamping grooves are provided on one side of the interior of the fixed block.

[0016] By adopting the above technical solution, when the two clamps are clamped and stabilized according to the size of the core sample, the clamping block will be on the same horizontal line as one of the slots, and the clamping block will be pushed into the corresponding slot according to spring 2 to effectively stabilize the position of the two clamps.

[0017] Furthermore, the end of the clamping block away from the second spring is arc-shaped, and the shape and size of the clamping slot are consistent with the arc-shaped end of the clamping block.

[0018] By adopting the above technical solution, after the influence of air pressure is lost, the card block and the card slot are separated through the arc guidance of the card block and the card slot.

[0019] Furthermore, a pressure sensor is fixedly connected to one side of the base plate, the pressure sensor is located inside the clamp body, the pressure sensor is electrically connected to an external controller, and the solenoid valve 1 is electrically connected to the external controller.

[0020] By adopting the above technical solution, the pressure condition inside the clamp body can be checked in real time through the pressure sensor. At the same time, when a deviation in the identified pressure occurs, the pressure inside the clamp body can be precisely controlled by controlling the solenoid valve 1 through an external controller.

[0021] Furthermore, a plurality of guide grooves are evenly formed on the inner wall of the holder body.

[0022] By adopting the above technical solution, the flow of the fracturing fluid in the core sample can be guided by the multiple guide grooves, ensuring the uniform distribution and effective penetration of the fluid in the experiment.

[0023] In summary, this application has at least one of the following beneficial effects:

[0024] 1. The present application is provided with a clamping assembly. When the core sample is placed inside the clamp body, a high-pressure air pump is used to pressurize the inside of the fixed block through the air inlet, so that the two clamping plates can be pushed to fit the core sample through the sealing plate, and the sealing air cushion can also be inflated through the air pipe, so that the clamp body can firmly hold the core sample inside the clamp body, greatly improving the stability and sealing of the core sample inside the clamp body, so that the clamp body can adapt to different sizes of core samples, and improve the flexibility and breadth of the experiment.

[0025] 2. This application is provided with a clamping part. As the sealing plate moves inside the fixed block, it will drive the clamping plate to clamp and stabilize the core sample according to the size of the core sample. When stable, the clamping block and one of the slots will be on the same horizontal line. At this time, through the cooperation of the clamping block, the slot and the air pressure inside the fixed block, the positions of the two clamping plates can be effectively stabilized, so that the core sample can be firmly stabilized inside the clamp body, reducing the possibility of the core sample shaking during the experiment.

[0026] 3. This application is provided with a pressure sensor and a guide groove. The high-pressure fluid replenishment pump is started by the software to pressurize the inside of the clamp body to the pressure value required for the experiment. At this time, the pressure situation inside the clamp body can be viewed in real time through the pressure sensor. At the same time, when the pressure deviation is identified, the solenoid valve can be controlled by an external controller to accurately control the pressure inside the clamp body. In addition, the multiple guide grooves can be used to guide the flow of fracturing fluid in the core sample to ensure uniform distribution and effective penetration of the fluid in the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the three-dimensional structure of the device body in this application.

[0028] Figure 2 It is a cross-sectional view of the main body of the device in this application.

[0029] Figure 3 It is a schematic diagram of the connection structure of the device body in this application.

[0030] Figure 4 It is a schematic diagram of the three-dimensional structure of the clamping assembly in this application.

[0031] Figure 5 It is a schematic diagram of the internal structure of the clamping assembly in this application.

[0032] Figure 6 It is a cross-sectional view of the clamping member in this application.

[0033] Description of reference numerals:

[0034] 1. Clamp body; 2. Bottom plate; 3. Fixing plate; 4. Core plug; 5. Nut; 6. Liquid inlet; 7. Liquid outlet; 8. Solenoid valve 1; 9. Fixing block; 10. Air inlet; 11. Solenoid valve 2; 12. Sealing air cushion; 13. Air pipe; 14. Sealing plate; 15. Connecting column; 16. Clamping plate; 17. Rubber pad; 18. Spring 1; 19. Connecting block; 20. Groove; 21. Spring 2; 22. Block; 23. Slot; 24. Pressure sensor; 25. Diversion groove. DETAILED DESCRIPTION

[0035] The following is combined with Figure 1 —6 Further explain this application in detail.

[0036] The embodiments of the present application disclose a dynamic simulation system for pre-fracture fluid performance in thick and hard critical layers.

[0037] Reference Figure 1 、 Figure 2 and Figure 3 , a dynamic simulation system for the performance of pre-fracture fracturing fluid in thick and hard key layers, including a clamper body 1, one end of the clamper body 1 is fixedly connected to a bottom plate 2, the outer wall of the other end of the clamper body 1 is fixedly connected to a fixing plate 3, a core plug 4 is installed on one side of the fixing plate 3, and a plurality of nuts 5 are symmetrically threadedly connected to one side of the core plug 4, and the plurality of nuts 5 can be threadedly connected to one side of the fixing plate 3. A liquid inlet 6 is fixedly connected to the clamper body 1, and a liquid outlet 7 is fixedly connected to the clamper body 1. One end of the liquid inlet 6 and the liquid outlet 7 is fixedly connected to an electromagnetic valve 8, and fixed blocks 9 are symmetrically fixedly connected to both sides of the clamper body 1, and a clamping assembly is installed inside the fixed block 9. A sealing air cushion 12 is fixedly connected to the inside of the clamper body 1, and a pressure sensor 24 is fixedly connected to one side of the bottom plate 2. The pressure sensor 24 is located inside the clamper body 1, and the pressure sensor 24 is electrically connected to an external controller, and the electromagnetic valve 8 is electrically connected to the external controller.

[0038] When conducting a simulation, first prepare the core samples, materials, water, etc. required for the experiment before the experiment, configure the fracturing fluid required for the experiment, then close all valves in the equipment, pour the fracturing fluid into the suction tank of the high-pressure fluid replenishment pump, then open the thermostat and adjust it to a suitable temperature, then take out the core sample for the experiment, and release the connection between the fixing plate 3 and the core plug 4 by screwing multiple nuts 5, so that the core plug 4 and nuts 5 are separated from the fixing plate 3, and then insert the core sample into the interior of the clamp body 1. At this time, the fixing plate 3 and the core plug 4 can be fitted together, and one end of the clamp body 1 can be sealed through the core plug 4 by screwing multiple nuts 5 in the opposite direction. After the core sample is placed inside the clamp body 1, the clamping assembly inside the fixing block 9 can be started to operate, and the operation of the clamping assembly can be used to clamp different sizes The core sample is firmly fixed in the inside of the clamp body 1. At the same time, when the clamping assembly is in operation, the sealing air cushion 12 can be inflated at the same time, thereby greatly improving the stability and sealing of the core sample in the clamp body 1. At the same time, the clamp body 1 can adapt to the different sizes of core samples, thereby improving the flexibility and breadth of the experiment. When the core sample is clamped stably, the medium in the container can be injected into the clamp body 1 through the liquid injection pump connected to the liquid inlet 6 to conduct the relevant liquid permeability test, and then the clamp body 1 is placed in the constant temperature box and the constant temperature box door is closed. The temperature of the constant temperature box is set according to the experimental requirements. After the temperature of the constant temperature box reaches the set stability, the confining pressure can be first injected into the filtration loss clamp by the ring pressure tracking pump, and then the back pressure pressure can be injected by the back pressure control pump.

[0039] Secondly, when conducting a dynamic filtration loss experiment of fracturing fluid, the core sample will be exposed to the fracturing fluid. At this time, the high-pressure fluid replenishment pump is started through the software to pressurize the inside of the clamp body 1 to the pressure value required for the experiment, and the pressure situation is checked in real time through the pressure sensor 24. Then the high-pressure circulation pump is started to make the fracturing fluid shear flow on the end face of the core sample and the core end face. At the same time, a filter cake is formed on the end face of the core under the action of the pressure difference. Part of the test liquid seeps out from the other end of the core through the filter cake, and the damage of the test liquid to the formation permeability is evaluated under real simulated formation conditions. After the core end face has been filtered out for a period of time according to the experimental requirements, the solenoid valve 8 can be opened to relieve the pressure inside the clamp body 1. Finally, the temperature control temperature of the thermostat is set to room temperature. After the temperature of the thermostat drops to room temperature, the thermostat is opened to perform a core permeability test on the core sample after filtration damage.

[0040] Reference Figure 1 、 Figure 4 and Figure 5The clamping assembly includes an air inlet 10 fixedly connected to one side of the two fixed blocks 9, one end of the air inlet 10 is fixedly connected to a solenoid valve 2 11, one side of the two fixed blocks 9 is fixedly connected with an air supply pipe 13, and the ends of the two air supply pipes 13 away from the fixed blocks 9 are fixedly connected to the sealing air cushion 12, and the interiors of the two fixed blocks 9 are slidably connected with a sealing plate 14, one side of the sealing plate 14 is provided with a clamping part, and one side of the sealing plate 14 is fixedly connected with a connecting column 15, which is slidably connected to the inside of the clamper body 1, and the end of the connecting column 15 away from the sealing plate 14 is fixedly connected to a splint 16, and the inner walls of the two splints 16 are fixedly connected to rubber pads 17, and the side of the sealing plate 14 away from the connecting column 15 is fixedly connected to a spring 18, and the end of the spring 18 away from the sealing plate 14 is fixedly connected to one side of the inner wall of the fixed block 9.

[0041] When in use, first open one of the solenoid valves 11, so that one of the air inlets 10 is connected to the external high-pressure air pump, and then the high-pressure air pump is used to inflate the interior of the fixed block 9 through the air inlet 10. At this time, the impact force of the air pump will push the sealing plate 14 to move inside the fixed block 9, so that the sealing plate 14 is gradually separated from one end of the air supply pipe 13. At this time, the gas will gradually enter the interior of the sealing air cushion 12 through the air supply pipe 13, so that the sealing air cushion 12 is gradually inflated and expanded, so that the sealing effect inside the clamp body 1 is maintained by the expanded sealing air cushion 12, reducing the leakage of liquid and gas, and when pushing the sealing plate 14 to move, the sealing The guidance of the plate 14 will also push the connecting column 15 to slide, thereby pushing the two clamping plates 16 to approach each other inside the clamp body 1 through the two connecting columns 15. When the two rubber pads 17 on one side of the two clamping plates 16 are in contact with the core sample, the inflation of the fixed block 9 can be stopped, and then the solenoid valve 11 is closed to prevent air pressure leakage, so that the clamp body 1 can firmly hold the core sample inside the clamp body 1, and at the same time, the sealing air cushion 12 can be inflated, which greatly improves the stability and sealing of the core sample inside the clamp body 1, so that the clamp body 1 can adapt to the different sizes of core samples, thereby improving the flexibility and breadth of the experiment.

[0042] Reference Figure 4 、 Figure 5 and Figure 6 The clamping part includes a connecting block 19 fixedly connected to one side of the sealing plate 14, a groove 20 is provided on one side of the connecting block 19, a spring 21 is fixedly connected to the inside of the groove 20, a clamping block 22 is slidably connected to the inside of the groove 20, one end of the spring 21 is fixedly connected to one end of the groove 20, a plurality of clamping grooves 23 are provided on one side of the interior of the fixed block 9, the end of the clamping block 22 away from the spring 21 is arc-shaped, and the shape and size of the clamping groove 23 are consistent with the arc-shaped end of the clamping block 22.

[0043] When in use, as the sealing plate 14 moves inside the fixed block 9, it will also drive the connecting block 19 to move. In the process of moving the connecting block 19, the inner wall of the fixed block 9 is squeezed, and the block 22 will first enter the inside of the groove 20. Because a plurality of slots 23 are provided on one side of the fixed block 9, and the shape and size of the slots 23 are consistent with the arc-shaped end of the block 22, when the two clamping plates 16 are clamped and stabilized according to the size of the core sample, the block 22 and one of the slots 23 will be at the same horizontal line. At this time, according to the rebound contraction of the spring 21, the block 22 will be pushed into the inside of the corresponding slot 23, so that the air in the block 22, the slot 23 and the fixed block 9 can be tightened. The pressure fit can effectively stabilize the position of the two clamps 16, so that the core sample can be firmly stabilized inside the clamp body 1. After the subsequent simulation is completed, the solenoid valve 2 11 can be opened to discharge the air pressure inside the fixed block 9. At this time, after the air pressure influence is lost, the sealing plate 14 will be pulled to move by the spring 18. At this time, the arc-shaped guidance of the block 22 and the slot 23 will separate the block 22 from the slot 23, thereby releasing the connection between the block 22 and the slot 23, so that the sealing plate 14 is reset inside the fixed block 9. When the sealing plate 14 moves and resets, it will drive the clamps 16 away from each other through the connecting column 15 to release the clamping of the core sample.

[0044] Reference Figure 1 and Figure 2 A plurality of guide grooves 25 are evenly formed on the inner wall of the clamp body 1 .

[0045] During use, the multiple guide grooves 25 provided can guide the flow of the fracturing fluid in the core sample, thereby ensuring uniform distribution and effective penetration of the fluid during the experiment.

[0046] The implementation principle of the dynamic simulation system for pre-fracture fracturing fluid performance of thick hard key layers in this embodiment is as follows: when conducting the simulation, first prepare the core samples, materials, water, etc. required for the experiment before the experiment, configure the fracturing fluid required for the experiment, then close all valves in the equipment, pour the fracturing fluid into the suction tank of the high-pressure fluid replenishment pump, then open the constant temperature box and adjust it to the appropriate temperature, then take out the core sample for the experiment, and release the connection between the fixing plate 3 and the core plug 4 by screwing multiple nuts 5, so that the core plug 4 and the nuts 5 are separated from the fixing plate 3, and then Then, the core sample is inserted into the interior of the holder body 1. At this time, the fixing plate 3 can be fitted with the core plug 4. By screwing multiple nuts 5 in the opposite direction, one end of the holder body 1 can be sealed through the core plug 4. After the core sample is placed inside the holder body 1, one of the solenoid valves 11 can be opened to connect one of the air inlets 10 to the external high-pressure air pump. Then, the high-pressure air pump is used to inflate the interior of the fixed block 9 through the air inlet 10. At this time, the impact force of the air pump will push the sealing plate 14 inside the fixed block 9. The sealing plate 14 is moved so that the sealing plate 14 is gradually separated from one end of the gas pipe 13. At this time, the gas will gradually enter the interior of the sealing air cushion 12 through the gas pipe 13, so that the sealing air cushion 12 is gradually inflated. The expanded sealing air cushion 12 is used to maintain the sealing effect inside the clamp body 1, reducing the leakage of liquid and gas. When the sealing plate 14 is pushed to move, the connecting column 15 is also pushed to slide by the guidance of the sealing plate 14, so that the two clamping plates 16 are pushed to the clamp body 1 through the two connecting columns 15. The interiors of the two clamps 16 are close to each other, and when the two rubber pads 17 on one side of the two clamps 16 are in contact with the core sample, the inflation of the fixing block 9 can be stopped, and then the electromagnetic valve 11 is closed to prevent air pressure leakage, so that the clamp body 1 can firmly hold the core sample inside the clamp body 1, and at the same time, the sealing air cushion 12 can be inflated, which greatly improves the stability and sealing of the core sample inside the clamp body 1, so that the clamp body 1 can adapt to different sizes of core samples, thereby improving the flexibility and versatility of the experiment;

[0047] In addition, as the sealing plate 14 moves inside the fixed block 9, it will also drive the connecting block 19 to move. In the process of the movement of the connecting block 19, the inner wall of the fixed block 9 is squeezed, and the card block 22 will first enter the interior of the groove 20. Because a plurality of card slots 23 are opened on one side of the fixed block 9, and the shape and size of the card slots 23 are consistent with the arc-shaped end of the card block 22, when the two clamping plates 16 are clamped and stabilized according to the size of the core sample, the card block 22 and one of the card slots 23 will be at the same horizontal line. At this time, according to the rebound contraction of the spring 21, the card block 22 will be pushed into the interior of the corresponding card slot 23, thereby through the card block 22, the card slot 23 and the internal air pressure of the fixed block 9. The cooperation can effectively stabilize the positions of the two clamping plates 16, so that the core sample can be firmly and stably fixed inside the clamp body 1. When the subsequent simulation is completed, the electromagnetic valve 2 11 can be opened to discharge the air pressure inside the fixed block 9. At this time, after the air pressure is lost, the sealing plate 14 is pulled to move by the spring 18. At this time, the arc-shaped guidance of the clamping block 22 and the clamping groove 23 will separate the clamping block 22 from the clamping groove 23, thereby releasing the clamping connection between the clamping block 22 and the clamping groove 23, so that the sealing plate 14 is reset inside the fixed block 9. When the sealing plate 14 moves and resets, it will drive the clamping plates 16 away from each other through the connecting column 15 to release the clamping of the core sample.

[0048] When the core sample is clamped stably, the medium in the container can be injected into the holder body 1 through the liquid injection pump connected to the liquid inlet 6 to perform the relevant liquid permeability test. Then, the holder body 1 is placed in the constant temperature box and the constant temperature box door is closed. The temperature of the constant temperature box is set according to the experimental requirements. After the constant temperature reaches the set stable temperature, the surrounding pressure tracking pump can be used to first inject the confining pressure into the filtration loss holder, and then the back pressure control pump can be used to inject the back pressure.

[0049] Secondly, when conducting a dynamic filtration loss experiment of fracturing fluid, the core sample will be exposed to the fracturing fluid. At this time, the high-pressure fluid replenishment pump is started through the software to pressurize the inside of the clamp body 1 to the pressure value required for the experiment, and the pressure situation is checked in real time through the pressure sensor 24. Then the high-pressure circulation pump is started to make the fracturing fluid shear flow on the end face of the core sample and the core end face. At the same time, a filter cake is formed on the end face of the core under the action of the pressure difference. Part of the test liquid seeps out from the other end of the core through the filter cake, and the damage of the test liquid to the formation permeability is evaluated under real simulated formation conditions. After the core end face has been filtered out for a period of time according to the experimental requirements, the solenoid valve 8 can be opened to relieve the pressure inside the clamp body 1. Finally, the temperature control temperature of the thermostat is set to room temperature. After the temperature of the thermostat drops to room temperature, the thermostat is opened to perform a core permeability test on the core sample after filtration damage.

Claims

1. A dynamic simulation system for the performance of pre-fracture fluid in thick and hard critical layers, comprising a holder body (1), characterized in that: One end of the clamp body (1) is fixedly connected to a base plate (2), the other end outer wall of the clamp body (1) is fixedly connected to a fixing plate (3), one side of the fixing plate (3) is installed with a core plug (4), one side of the core plug (4) is symmetrically threaded with a plurality of nuts (5), and the plurality of nuts (5) can be threadedly connected to one side of the fixing plate (3), the clamp body (1) is fixedly connected to a liquid inlet (6), the clamp body (1) is fixedly connected to a liquid outlet (7), one end of each of the liquid inlet (6) and the liquid outlet (7) is fixedly connected to a solenoid valve (8), the two sides of the clamp body (1) are symmetrically fixedly connected to fixing blocks (9), the interior of the fixing block (9) is installed with a clamping assembly, and the interior of the clamp body (1) is fixedly connected to a sealing air cushion (12); The clamping assembly includes an air inlet (10) fixedly connected to one side of two fixed blocks (9), one end of the air inlet (10) is fixedly connected to a second solenoid valve (11), one side of the two fixed blocks (9) is penetrated and fixedly connected to an air supply pipe (13), one end of the two air supply pipes (13) away from the fixed blocks (9) is penetrated and fixedly connected to a sealing air cushion (12), the interior of the two fixed blocks (9) is slidably connected to a sealing plate (14), and one side of the sealing plate (14) is provided with a clamping member.

2. A dynamic simulation system for pre-fracture fluid performance in thick and hard critical layers according to claim 1, characterized in that: A connecting column (15) is fixedly connected to one side of the sealing plate (14), and the connecting column (15) is slidably connected to the inside of the clamp body (1). An end of the connecting column (15) away from the sealing plate (14) is fixedly connected to a clamping plate (16).

3. A dynamic simulation system for pre-fracture fluid performance in thick and hard critical layers according to claim 2, characterized in that: The inner walls of the two clamping plates (16) are fixedly connected with rubber pads (17), the side of the sealing plate (14) away from the connecting column (15) is fixedly connected with a spring 1 (18), and the end of the spring 1 (18) away from the sealing plate (14) is fixedly connected to the inner wall of the fixed block (9).

4. The dynamic simulation system for pre-fracture fluid performance in thick and hard critical layers according to claim 1, characterized in that: The clamping member comprises a connecting block (19) fixedly connected to one side of the sealing plate (14), a groove (20) being provided on one side of the connecting block (19), a spring 2 (21) being fixedly connected inside the groove (20), a clamping block (22) being slidably connected inside the groove (20), one end of the spring 2 (21) being fixedly connected to one end of the groove (20), and a plurality of clamping grooves (23) being provided on one side of the interior of the fixing block (9).

5. A dynamic simulation system for pre-fracture fluid performance in thick and hard critical layers according to claim 4, characterized in that: The end of the clamping block (22) away from the second spring (21) is arc-shaped, and the shape and size of the clamping slot (23) are consistent with the arc-shaped end of the clamping block (22).

6. The dynamic simulation system for pre-fracture fluid performance in thick and hard critical layers according to claim 1, characterized in that: A pressure sensor (24) is fixedly connected to one side of the base plate (2), and the pressure sensor (24) is located inside the clamp body (1). The pressure sensor (24) is electrically connected to an external controller, and the solenoid valve (8) is electrically connected to the external controller.

7. The dynamic simulation system for pre-fracture fluid performance in thick and hard critical layers according to claim 1, characterized in that: A plurality of guide grooves (25) are evenly arranged on the inner wall of the clamp body (1).

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