Fracture plate model and simulation experiment device for proppant migration and plugging under complex fracture network conditions

Abstract

This invention proposes a joint plate model and simulation experimental device for proppant migration and plugging under complex joint network conditions, relating to the field of petrochemical technology. The joint plate model includes a joint plate model body, a transparent panel, a square moving piston, multiple flow strips, a joint width adjustment mechanism, and two multi-stage flanges. The transparent panel, the square moving piston, and the inner wall of the mounting groove form a sealed cavity. The square moving piston has a sealing sliding fit with the inner wall of the mounting groove and can reciprocate in a direction perpendicular to the transparent panel. The joint width adjustment mechanism drives the square moving piston to adjust the distance between the transparent panel and the square moving piston. This joint plate model and simulation experimental device for proppant migration and plugging under complex joint network conditions enables simulation of proppant migration and plugging in large-scale high-pressure complex joint networks under multi-stage, multi-plate, and different angle conditions.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, and in particular to a seam plate model and simulation experimental device for proppant migration and plugging under complex seam conditions. Background Technology

[0002] During oilfield operations, especially in the production enhancement phase, formation fracturing is necessary. This fracturing process requires evaluating the particle effect of the proppant and the proppant-carrying capacity of the fracturing fluid within the fracture. Therefore, simulation experiments involving proppant and fracturing fluid are necessary to obtain performance evaluations of these components during fracturing.

[0003] However, existing proppant and fracturing fluid simulation equipment is too simple, small in scale, and the simulated pressure is relatively low. It cannot realistically simulate the proppant placement and migration patterns in complex fractures under large-scale conditions and the flow under high pressure, thus limiting its guiding role in formation fracturing operations.

[0004] In view of this, based on years of experience in production and design in this and related fields, the inventor has designed a seam plate model and simulation experimental device for proppant migration and sealing under complex seam conditions through repeated experiments, in order to solve the problems existing in the prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a plate model and simulation experimental device for proppant migration and plugging under complex seam conditions, so as to realize the simulation experiment of proppant migration and plugging of large-scale high-pressure complex seam under multi-level, multi-plate and different angle conditions.

[0006] To achieve the above objectives, this invention proposes a seam plate model for proppant migration and sealing under complex seam mesh conditions, wherein the seam plate model includes: The main body of the seam panel model has a mounting slot; A transparent panel is sealed and installed in the opening of the mounting groove, thus closing the mounting groove. A square movable piston is located in the mounting groove and is arranged parallel to the transparent panel. The transparent panel, the square movable piston, and the inner wall of the mounting groove form a sealed cavity. The square movable piston is in a sealed sliding fit with the inner wall of the mounting groove and can reciprocate in a direction perpendicular to the transparent panel. Multiple flow bars are disposed within the sealed cavity, and the multiple flow bars have various curvatures to simulate different fluid flow states; A seam width adjustment mechanism, connected to the square moving piston, is used to drive the square moving piston to move in order to adjust the distance between the transparent panel and the square moving piston; Two multi-stage flanges are respectively disposed on opposite sides of the seam plate model body, and each multi-stage flange is sealed to the seam plate model body and communicates with the sealing cavity.

[0007] This invention also proposes a simulation experimental device for proppant migration and occlusion under complex mesh conditions, wherein the simulation experimental device includes: The slurry mixing tank is used to stir and mix proppant and fracturing fluid to form a proppant-carrying fluid; A screw pump, the inlet of which is connected to the outlet of the slurry mixing tank, is used to provide power for the circulation of the sand-carrying liquid; At least one seam plate model as described above, wherein the outlet of the screw pump is connected to the inlet of the seam plate model via a pipeline; A filter vessel is connected to the outlet of the fracture plate model via a pipeline. The filter vessel is equipped with a filter element for filtering the proppant in the proppant-carrying fluid flowing out of the fracture plate model. The outlet of the filter vessel is connected to the inlet of the slurry mixing tank via a pipeline so that the filtered fracturing fluid can flow back into the slurry mixing tank.

[0008] Compared with the prior art, the present invention has the following features and advantages: The proposed model for proppant migration and plugging under complex fracture network conditions uses a transparent panel, a square movable piston, and the inner wall of the mounting groove to form a sealed cavity to simulate formation fractures. The distance between the transparent panel and the square movable piston is the fracture width. Through the transparent panel, researchers can intuitively observe the migration trajectory, settling velocity, and evolution of sand plugging in the fracture network in real time, providing intuitive and quantitative experimental data support for the study of proppant placement mechanism.

[0009] The simulation experimental device for proppant migration and plugging under complex fracture network conditions proposed in this invention uses a filter kettle to completely filter the proppant in the outlet fluid, allowing only the fracturing fluid to flow back to the slurry mixing tank, and then filter and recycle the fracturing fluid, which greatly reduces the cost of experimental consumables and makes it possible to conduct large-scale fracture plate experiments with long duration and large amount of sand without having to frequently interrupt the experiment and re-prepare the solution. Attached Figure Description

[0010] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0011] Figure 1 This is a schematic diagram of the structure of the simulation experimental device proposed in this invention; Figure 2 This is a schematic diagram of the structure of the seam plate model proposed in this invention; Figure 3 This is a schematic diagram of the installation of the flow bar in this invention; Figure 4 This is a schematic diagram of the installation of the transparent panel in this invention.

[0012] Explanation of reference numerals in the attached figures

[0013] 1. Control and communication line; 2. Screw pump; 3. First joint; 4. Screw elevator; 5. Feed hopper; 6. Slurry mixing tank; 7. Ball valve; 8. Bypass valve; 9. Flange; 10. Filter valve; 11. Seam plate model; 111. Seam plate model body; 112. Support beam; 12. Piping; 13. Third joint; 14. Filter tank; 15. Filter element; 16. Prop; 17. Multi-stage flange; 18. Data acquisition and control system; 19. Measurement signal 20. Second connector; 21. Square moving piston; 22. Drive motor; 23. Synchronous sprocket; 24. Chain; 25. Adjusting rod; 26. Bearing; 27. Seal; 28. Fixing rod; 29. ​​Displacement detection device; 30. Sand-carrying fluid; 31. Pressure measuring point; 32. Temperature measuring point; 33. Flow bar; 34. Pressure plate; 35. Transparent panel; 36. Locking bolt; 37. Multi-stage flange connection section; 100. Simulation experimental device. Detailed Implementation

[0014] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, and these should all be considered to fall within the scope of the invention.

[0015] This invention proposes a seam plate model 11 for proppant migration and sealing under complex seam mesh conditions, such as... Figure 2 As shown, the seam panel model 11 includes: The main body of the seam panel model 111 has a mounting slot; A transparent panel 35 is sealed and installed in the opening of the mounting groove, thus closing the mounting groove. A square movable piston 21 is located in the mounting groove and is set parallel to the transparent panel 35. The transparent panel 35, the square movable piston 21 and the inner wall of the mounting groove form a sealed cavity. The square movable piston 21 is in a sealed sliding fit with the inner wall of the mounting groove and can reciprocate in a direction perpendicular to the transparent panel 35. Multiple flow bars 33 are detachably installed in the sealed cavity. The multiple flow bars 33 have various curvatures to simulate different fluid flow states. A seam width adjustment mechanism is connected to a square moving piston 21 and is used to drive the square moving piston 21 to move in order to adjust the distance between the transparent panel 35 and the square moving piston 21. Two multi-stage flanges 17 are respectively set on opposite sides of the seam plate model body 111. Each multi-stage flange 17 is sealed to the seam plate model body 111 and communicates with the sealing cavity.

[0016] The fracture plate model 11 proposed in this invention for proppant migration and plugging under complex fracture network conditions forms a sealed cavity by a transparent panel 35, a square movable piston 21, and the inner wall of the mounting groove to simulate formation fractures. The distance between the transparent panel 35 and the square movable piston 21 is the fracture width. Through the transparent panel 35, researchers can intuitively observe the migration trajectory, settling velocity, and evolution of sand plugging process of the proppant-carrying fluid 30 (a mixture of proppant and fracturing fluid) in the fracture network in real time, providing intuitive and quantitative experimental data support for the study of proppant placement mechanism.

[0017] The proposed seam plate model 11 for proppant transport and sealing under complex seam conditions has a square moving piston 21 that can reciprocate along a direction perpendicular to the transparent panel 35 under the drive of the seam width adjustment mechanism to achieve different seam widths. Without changing the model, it can realize accurate comparison experiments of a single variable (seam width), which greatly improves experimental efficiency and data comparability.

[0018] The seam plate model 11 proposed in this invention for proppant transport and sealing under complex seam conditions has multiple flow strips 33 set in the sealing cavity. The multiple flow strips 33 have various curvatures, which can make the sand-carrying liquid 30 generate different fluid flow states, thereby more realistically simulating the complex seam morphology.

[0019] In an optional embodiment of the present invention, a plurality of pressure measuring points 31 and a plurality of temperature measuring points 32 are provided within the sealed cavity. Each pressure measuring point 31 is equipped with a pressure measuring instrument, and each temperature measuring point 32 is equipped with a temperature measuring instrument, to measure the pressure and temperature parameters at different turbulence locations within the sealed cavity. By observing the temperature field, pressure field, and the effect of flow around the proppant, a better simulation evaluation of the proppant and fracturing fluid can be performed.

[0020] In one optional example of this implementation, pressure measuring point 31 and temperature measuring point 32 are interspersed.

[0021] In an optional example of this embodiment, the pressure measuring instrument and the temperature measuring instrument are detachably fixed to the seam plate model body 111.

[0022] In an optional embodiment of the invention, a plurality of flow strips 33 are detachably fixedly connected to the seam plate model body 111.

[0023] In an optional embodiment of the present invention, such as Figure 3 As shown, multiple flow strips 33, multiple pressure measuring points 31, and multiple temperature measuring points 32 are distributed in a cross pattern.

[0024] In an optional embodiment of the present invention, the flow bar 33 is formed by pressing stainless steel plate, which has high strength and corrosion resistance.

[0025] In an optional embodiment of the invention, different flow strips 33 have different curvatures to simulate different fluid flow regimes.

[0026] In an optional embodiment of the invention, the transparent panel 35 is pressed onto the seam plate model body 111 by a clamping plate 34 and a plurality of locking bolts 36.

[0027] In this embodiment, the clamping plate 34 is pressed against the transparent panel 35 on the surface of the sewing board model body 111 facing away from it. Multiple locking bolts 36 are evenly distributed on the clamping plate 34. Each locking bolt 36 passes through the clamping plate 34 and the transparent panel 35 and is threadedly connected to the sewing board model body 111, thereby sealing and fixing the transparent panel 35 to the sewing board model body 111, so that the transparent panel 35 can withstand greater pressure and ensure the sealing between the transparent panel 35 and the sewing board model body 111.

[0028] In an optional embodiment of the present invention, the transparent panel 35 is composed of multiple transparent panel pieces. A clamping plate 34 is provided at the seam between two adjacent transparent panel pieces. A support beam 112 is provided on the panel model body 111 to align with the seam. The clamping plate 34 and the support beam 112 clamp the two transparent panel pieces and cover the seam, thereby achieving a sealed connection between the two transparent panel pieces. Furthermore, a locking bolt 36 passes through the clamping plate 34, the transparent panel piece, and the support beam 112 in sequence, sealing and fixing the clamping plate 34, the transparent panel piece, and the support beam 112 together.

[0029] By adopting the above structure, large-sized windows can be decomposed into standard-sized small panels, significantly reducing processing difficulty and manufacturing costs, making it physically possible to simulate larger-scale mesh models. Simultaneously, the support beam 112 and the clamping plate 34 form a double-sided reinforcing rib structure at the joint, transforming the joint into a rigid support point and effectively counteracting the outward thrust of the high-pressure fluid within the sealed cavity on the transparent panel 35. Multiple locking bolts 36 are evenly distributed on the transparent panel bodies on both sides of the joint via the clamping plate 34, and then transmitted to the high-rigidity mesh model body 111 via the support beam 112. This significantly shortens the stress span of the transparent panel 35, allowing it to withstand higher experimental pressures than a single large panel under the same wall thickness, significantly improving the safety of experimental operations.

[0030] In one optional example of this implementation, the transparent panel is made of plexiglass or tempered glass.

[0031] In an optional embodiment of this implementation, a sealing ring is also provided between the transparent panel 35 and the seam plate model body 111 to ensure a high-pressure seal between the transparent panel 35 and the seam plate model body 111.

[0032] In an optional embodiment of the present invention, the seam width adjustment mechanism includes: Multiple adjustment rods 25 are set on the side of the sewing board model body 111 facing away from the transparent panel 35. The multiple adjustment rods 25 are spaced apart, and each adjustment rod 25 vertically penetrates the sewing board model body 111 and is fixedly connected to the square moving piston 21. The drive assembly is connected to and drives multiple adjusting rods 25 to move synchronously in a direction perpendicular to the seam board model body 111. Using this structure, the square moving piston 21 is moved synchronously by multiple adjusting rods 25, achieving synchronous and precise adjustment of the relatively large square moving piston 21 and ensuring the seal between the square moving piston 21 and the seam board model body 111.

[0033] In one optional example of this embodiment, multiple adjusting rods 25 are evenly distributed on the side of the seam plate model body 111 facing away from the transparent panel 35. In this way, the pushing and pulling forces applied by the multiple adjusting rods 25 to the square moving piston 21 are more uniform, ensuring the smooth movement of the square moving piston 21.

[0034] In an optional example of this embodiment, the drive assembly includes a drive motor 22, a chain 24, and multiple synchronous sprockets 23. The synchronous sprockets 23 are rotatably mounted on the seam plate model body 111 via bearings 26. Each synchronous sprocket 23 corresponds to an adjusting rod 25. The synchronous sprockets 23 and the adjusting rods 25 are coaxially arranged, and the rotation shaft of the synchronous sprocket 23 is threadedly engaged with the adjusting rod 25. The drive motor 22 synchronously drives the multiple synchronous sprockets 23 via the chain 24 to synchronously drive each adjusting rod 25 to advance or retract synchronously.

[0035] In an alternative example, one end of the bearing 26 is detachably and sealingly connected to the seam plate model body 111, and the adjusting rod 25 passes through the seam plate model body 111 and is in a sealing sliding fit with the seam plate model body 111.

[0036] In an optional example, a seal 27 is provided between the adjusting rod 25 and the seam plate model body 111.

[0037] Preferably, the seal 27 is a rotary seal.

[0038] In an optional embodiment of the present invention, a displacement detection device 29 is also provided on the seam plate model body 111 to detect the displacement of the square moving piston 21 and realize the real-time measurement of the displacement of the square moving piston 21.

[0039] In an optional example of this implementation, the displacement detection device 29 is connected to the square movable piston 21 via a fixed rod 28.

[0040] In an optional embodiment of the present invention, the multi-stage flange 17 is a multi-channel welded flange with multiple connection ports in multiple directions, so that proppant fluid 30 (a mixture of proppant and fracturing fluid) from multiple directions can enter the fracture plate model 11 through the multi-stage flange 17.

[0041] In one optional example of this implementation, such as Figure 4 As shown, the multi-level flange 17 is connected to the seam plate model body 111 via the multi-level flange connecting section 37 to achieve the combination of different seam plate models 11. The connection between the multi-level flange 17 and the multi-level flange connecting section 37 allows multiple different seam plate models 11 to be combined together. Two adjacent different seam plate models 11 can be connected via the multi-level flanges 17 on the left and right sides. Since the multi-level flange 17 has connection ports in multiple directions, the most suitable direction of connection can be selected for connection, while other unnecessary connection ports are closed, allowing each seam plate model 11 to have different tilt directions or placement positions, thereby simulating the shape of a multi-level seam mesh.

[0042] In an optional example, the multi-stage flange 17 is detachably bolted to the multi-stage flange connection section 37.

[0043] In an optional example, a sealing ring can be arranged inside the multi-stage flange 17 to achieve a seal for the system.

[0044] In an optional embodiment of the present invention, the dimensions of the seam plate model 11 are preferably 1100mm × 350mm (length × width).

[0045] In an optional embodiment of the present invention, the seam width adjustment range of the seam plate model 11 is 0.01-10mm.

[0046] In an optional embodiment of the present invention, a plurality of moisture-filtering valves 10 are connected to the seam plate model 11.

[0047] like Figure 1 As shown, the present invention also proposes a simulation experimental device 100 for proppant migration and plugging under complex mesh conditions, comprising: The slurry mixing tank 6 is used to stir and mix proppant and fracturing fluid to form proppant-carrying fluid (a mixture of proppant and fracturing fluid). Screw pump 2, whose inlet is connected to the outlet of slurry mixing tank 6, is used to provide power for the circulation of sand-carrying liquid; At least one of the seam plate models 11 as described above, the outlet of the screw pump 2 is connected to the inlet of the seam plate model 11 via a pipeline; The filter vessel 14 is connected to the outlet of the fracture plate model 11 via a pipeline. The filter vessel 14 is equipped with a filter element for filtering the proppant in the sand-carrying fluid flowing out of the fracture plate model 11. The outlet of the filter vessel 14 is connected to the inlet of the slurry mixing tank 6 via a pipeline 12 so that the filtered fracturing fluid flows back into the slurry mixing tank 6.

[0048] The simulation experimental device 100 for proppant migration and plugging under complex fracture network conditions proposed in this invention uses a filter vessel 14 to effectively retain the proppant in the outlet fluid, allowing only the fracturing fluid to flow back to the slurry mixing tank 6. By filtering, the fracturing fluid is recovered and recycled, which greatly reduces the cost of experimental consumables and makes it possible to conduct large-scale fracture plate experiments with long duration and large sand volume without having to frequently interrupt the experiment and re-prepare the solution.

[0049] In an optional embodiment of the present invention, the simulation experimental device 100 for proppant migration and plugging under complex crack network conditions includes multiple crack plate models 11. The multiple crack plate models 11 are connected by multi-level flanges 17 to form a fluid communication relationship in a group consisting of series branches, parallel branches and their combinations. The spatial arrangement direction of each crack plate model 11 includes at least the horizontal direction and / or the vertical direction to simulate a three-dimensional network crack system.

[0050] In this embodiment, the multi-level flanges 17 at the outlet and inlet of the seam plate model 11 have reserved interfaces in multiple directions. By connecting the multi-level flanges 17, multiple forms of cracks (seam plate model 11) exist in the same circulation loop, breaking the limitation that the traditional single simulation test device can only simulate one crack angle, and effectively simulating the movement pattern within the multi-level seam network of cracks.

[0051] In this embodiment, by combining multiple seam plate models 11 in different quantities and positions, it is possible to simulate the main seam and branch seam under different seam network conditions, so as to realize the high-pressure sealing and migration simulation experiment of proppant under complex conditions.

[0052] In an optional embodiment of the present invention, each seam plate model 11 is provided with a bypass valve 8 on its inlet and outlet pipes to control the opening and closing of the corresponding seam plate model 11's pipe, so as to meet different connection conditions.

[0053] In an optional embodiment of the present invention, the simulation experimental apparatus 100 further includes a screw conveyor 4, which is connected to the slurry mixing tank 6 and is used to deliver proppant into the slurry mixing tank 6.

[0054] In an optional embodiment of the present invention, the proppant is sand particles, and the screw conveyor 4 serves as the main power component for providing and conveying sand. The screw mechanism driven by the motor conveys the sand through the feed hopper 5 into the tank of the slurry mixing tank 6.

[0055] In one optional example of this embodiment, the slurry mixing tank 6 uses a top-mounted rotary motor to stir and mix the substances inside the tank evenly.

[0056] In an optional embodiment of the present invention, the outlet of the slurry mixing tank 6 is connected to the inlet of the screw pump 2 via the first connector 3.

[0057] In an optional example of this implementation, the first connector 3 is an 8040 reducer.

[0058] In an optional embodiment of the present invention, a second connector 20, a flange 9, a ball valve and a DN20 flange are sequentially provided on the pipeline between the screw pump 2 and the slotted plate model 11.

[0059] In this embodiment, the second connector 20 is a 6520 reducer.

[0060] In an optional embodiment of the present invention, the connecting pipeline between the outlet of the slotted plate model 11 and the filter tank 14 is sequentially provided with a third connector 13 (4020 reducer), a DN40 flange and a corresponding ball valve.

[0061] In an optional embodiment of the present invention, a DN40 and a ball valve 7 are provided on the pipeline 12. When the simulation experimental device 100 is running, the ball valve 7 at the upper end is opened, and the fracturing fluid can be filtered through the filter vessel 14 and then flowed back into the slurry mixing tank 6.

[0062] In an optional embodiment of the present invention, a settling device is provided at the bottom of the filter vessel 14, and the filtered proppant 16 can enter the settling device at the bottom for repeated use.

[0063] In an optional embodiment of the present invention, the proppant transport and plugging simulation experimental device 100 further includes a data acquisition and control system 18. The data acquisition and control system 18 is connected to the slurry mixing tank 6, the screw pump 2 and the screw elevator 4 respectively through the control communication line 1, and is used to control the motor speed of the slurry mixing tank 6 and the screw pump 2 as well as the conveying capacity of the screw elevator 4.

[0064] In an optional example of this implementation, the data acquisition and control system 18 is connected to each pressure measuring instrument and each temperature measuring instrument via measurement signal lines 19 to acquire pressure signals and temperature signals.

[0065] Please refer to Figure 1 , Figure 2 The following is a detailed description of the specific implementation process of the seam plate model 11 and the simulation experimental device 100 for proppant migration and sealing under complex seam conditions proposed in this invention, with reference to an embodiment.

[0066] The simulation experimental device 100 in this invention enables the proppant-carrying fluid (a mixture of proppant and fracturing fluid) to circulate through the connection of different components, pipelines 12, and valves. The flow simulation is carried out in the fracture plate model 11. Each fracture plate model 11 is designed with multi-stage flanges 17 at both ends. The multi-stage flanges 17 can realize the connection and sealing of different fracture plate models 11. The proppant 16 (sand body) is filtered through the filter vessel 14 connected to the outlet of the multi-stage flange 17. The fluid is transported to the slurry mixing tank 6 by the circulation power of the screw pump 2. The fluid coming out of the filter vessel 14 and into the pipeline 12 becomes fracturing fluid without proppant after filtration. The flow rate of the fracturing fluid is matched with the amount of sand transported by the screw elevator 4. Under the action of the screw pump 2 and the screw elevator 4, they are synchronously injected and circulated. The mixture is stirred and mixed in the slurry mixing tank 6. It enters the screw pump 2 from the pipeline 12 and the first connector 3 at the lower end of the slurry mixing tank 6. Then, under the action of the screw pump 2, it is circulated again and then enters the fracture plate model 11 to complete the entire flow cycle.

[0067] The proppant and fracturing fluid circulate and flow in the fracture surface simulated by the fracture plate model 11. By controlling the fracture width of the fracture plate model 11, the proppant migration and sealing under different fracture width conditions are simulated.

[0068] Among them, the screw conveyor 4 serves as the main power component for providing and conveying sand. Driven by a motor, the screw mechanism transports the sand through the feed hopper 5 to the slurry mixing tank 6. The slurry mixing tank 6 uses a rotating motor at the top to stir and mix the materials inside the tank evenly. Simultaneously, the slurry mixing tank 6 also functions to recover the fracturing fluid flowing through the pipeline 12. When the simulation experimental device 100 is running, opening the upper ball valve 7 allows the liquid to be filtered through the filter vessel 14 and then returned to the slurry mixing tank 6. At the lower end of the slurry mixing tank 6, the outlet is connected to the screw pump 2 via valves and pipelines. The screw pump 2, driven by the rotating motor and the internal screw, draws the mixture from the slurry mixing tank 6 into the internal... The cavity, under the action of the screw of the screw pump 2, pushes the mixture to the reducing flange of the second connector 20. At the outlet of the screw pump 2, it is connected to the multi-stage flange 17 at the inlet of the seam plate model 11 through the second connector 20, ball valve and DN20 flange. Multi-stage flanges 17 are arranged at both ends of the seam plate model 11 to connect various directions. They are sealed by bolts and sealing rings. Through the multi-stage flanges 17, different seam plate models 11 can be connected to form various branch seams and different main seams in the vertical and horizontal directions. Bypass valves 8 are arranged at the inlet and outlet positions of different seam plate models 11 to open and close the pipelines of different branch seams to meet different connection conditions.

[0069] At the outlet of the seam plate model 11, it is connected to the third joint 13, DN40 flange, corresponding ball valve and filter tank 14 through pipeline and third joint 13. The outlet of filter tank 14 is connected to the slurry mixing tank 6 through DN40, ball valve and pipeline 12 to achieve fluid circulation. The main function of filter tank 14 is to filter the proppant 16 (sand body) in the sand-carrying liquid circulating out of seam plate model 11 through filter element 15 (e.g. filter screen). The filtered proppant 16 can enter the sedimentation device at the bottom and be reused repeatedly. The outflowing medium does not contain proppant. Therefore, the fluid at the outlet can be used as the fluid source in slurry mixing tank 6. The fluid after removing proppant 16 and the sand on the screw conveyor 4 can enter slurry mixing tank 6 in a fixed ratio for multiple cycles.

[0070] During the cyclic process, the overall simulation experimental device 100 performs data acquisition, processing, and control through the control communication line 1, the measurement signal line 19, and the data acquisition and control system 18. The control communication line 1 controls the rotation of the motors of the slurry mixing tank 6 and the screw pump 2, while the data acquisition and control system 18 performs frequency conversion control to adjust the flow rates of the screw pump 2 and the screw elevator 4. The parameters of each temperature measuring instrument and each pressure measuring instrument are acquired through the measurement signal line 19 and displayed in real time.

[0071] The data acquisition and control system 18 serves as the central hub, acquiring signals and performing real-time control through control communication lines 1 and measurement signal lines 19 at various locations.

[0072] The detailed explanations of the above embodiments are intended only to explain the present invention so as to facilitate a better understanding of the present invention. However, these descriptions should not be construed as limiting the present invention for any reason. In particular, the various features described in different embodiments can be arbitrarily combined with each other to form other embodiments. Unless there is an explicit description to the contrary, these features should be understood to be applicable to any embodiment, and not limited to the described embodiments.

Claims

1. A seam plate model for proppant transport and sealing under complex seam mesh conditions, characterized in that, The seam panel model includes: The main body of the seam panel model has a mounting slot; A transparent panel is sealed and installed in the opening of the mounting groove, thus closing the mounting groove. A square movable piston is located in the mounting groove and is arranged parallel to the transparent panel. The transparent panel, the square movable piston, and the inner wall of the mounting groove form a sealed cavity. The square movable piston is in a sealed sliding fit with the inner wall of the mounting groove and can reciprocate in a direction perpendicular to the transparent panel. Multiple flow bars are disposed within the sealed cavity, and the multiple flow bars have various curvatures to simulate different fluid flow states; A seam width adjustment mechanism, connected to the square moving piston, is used to drive the square moving piston to move in order to adjust the distance between the transparent panel and the square moving piston; Two multi-stage flanges are respectively disposed on opposite sides of the seam plate model body, and each multi-stage flange is sealed to the seam plate model body and communicates with the sealing cavity.

2. The seam plate model for proppant migration and sealing under complex seam mesh conditions as described in claim 1, characterized in that, The sealed cavity is equipped with multiple pressure measuring instruments and / or multiple temperature measuring instruments.

3. The seam plate model for proppant migration and sealing under complex seam mesh conditions as described in claim 1, characterized in that, The transparent panel is pressed onto the body of the seam plate model by a pressure plate and multiple locking bolts.

4. The seam plate model for proppant migration and sealing under complex seam mesh conditions as described in claim 1, characterized in that, The seam width adjustment mechanism includes: Multiple adjustment rods are provided on the side of the sewing board model body facing away from the transparent panel. The multiple adjustment rods are spaced apart, and each adjustment rod vertically penetrates the sewing board model body and is fixedly connected to the square movable piston. A drive assembly is connected to and drives the plurality of adjustment rods to move synchronously in a direction perpendicular to the body of the seam board model.

5. The seam plate model for proppant migration and sealing under complex seam mesh conditions as described in claim 4, characterized in that, The drive assembly includes a drive motor, a chain, and multiple synchronous sprockets. The synchronous sprockets are rotatably mounted on the seam plate model body via bearings. Each synchronous sprocket corresponds to one of the adjusting rods. The synchronous sprockets and adjusting rods are coaxially arranged and threadedly engaged. The drive motor synchronously drives multiple synchronous sprockets through the chain to synchronously drive each adjusting rod to advance or retract synchronously.

6. The seam plate model for proppant migration and sealing under complex seam mesh conditions as described in claim 1, characterized in that, The seam plate model body is also equipped with a displacement detection device for detecting the displacement of the square moving piston.

7. The seam plate model for proppant migration and sealing under complex seam mesh conditions as described in claim 1, characterized in that, The multi-stage flange is connected to the seam plate model body through a multi-stage flange connection section.

8. A simulation experimental apparatus for proppant migration and plugging under complex mesh conditions, characterized in that, The simulation experimental apparatus includes: A slurry mixing tank is used to stir and mix proppant and fracturing fluid to form a proppant-carrying fluid. A screw pump, the inlet of which is connected to the outlet of the slurry mixing tank, is used to provide power for the circulation of the sand-carrying liquid; At least one seam board model as described in any one of claims 1 to 7, wherein the outlet of the screw pump is connected to the inlet of the seam board model via a pipeline; A filter vessel is connected to the outlet of the fracture plate model via a pipeline. The filter vessel is equipped with a filter element for filtering the proppant in the proppant-carrying fluid flowing out of the fracture plate model. The outlet of the filter vessel is connected to the inlet of the slurry mixing tank via a pipeline so that the filtered fracturing fluid can flow back into the slurry mixing tank.

9. The simulation experimental apparatus for proppant migration and plugging under complex mesh conditions as described in claim 8, characterized in that, The simulation experimental device includes multiple seam plate models, which are connected by multi-level flanges to form a fluid communication relationship in a group consisting of series branches, parallel branches and their combinations. The spatial arrangement direction of each seam plate model includes at least the horizontal direction and / or the vertical direction.

10. The simulation experimental apparatus for proppant migration and closure under complex mesh conditions as described in claim 8, characterized in that, The simulation experimental device also includes a data acquisition and control system, which is connected to the slurry mixing tank and the screw pump respectively through control communication lines, and is used to control the motor speed of the slurry mixing tank and the screw pump.

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