Simulation device for in-source accumulation efficiency based on micro-fracture quantity

Abstract

This invention relates to the field of source-end reservoir formation simulation technology, specifically a simulation device based on the effect of microfracture number on source-end reservoir formation efficiency. The device includes a test platform, an experimental chamber, and a fracture-forming assembly. An experimental chamber is fixed to the upper side of the test platform, and a loading container containing reservoir samples is placed inside. A borehole is vertically drilled at the center of the reservoir sample, and an injection mechanism slides through the borehole. A storage tank is located on one side of the test platform, connected to the injection mechanism via a delivery pump. A pressure-applying assembly is positioned on the upper side of the reservoir sample, capable of compressing the upper surface of the sample. This invention features a reasonable and compact structure, is easy to use, and allows for the injection of oil and gas into the reservoir sample using the injection mechanism, thereby artificially controlling the distribution of oil and gas to form specific reservoirs. The pressure-applying assembly simulates ground pressure movement, and the fracture-forming assembly assists in the formation of flow fractures within the reservoir sample, enabling multi-faceted experimental simulations.

Description

Technical Field

[0001] This invention relates to the field of source-endogenous hydrocarbon accumulation simulation experiment technology, and is a simulation device based on the effect of the number of microcracks on source-endogenous hydrocarbon accumulation efficiency. Background Technology

[0002] In oil and gas exploration and development, oil and gas in underground reservoirs can enter the wellbore and be extracted. Generally, the presence of microfractures can improve the permeability and porosity of the reservoir, thereby increasing the flow and recovery rate of oil and gas in the reservoir.

[0003] Chinese patent application CN118361231A discloses a simulation experimental device for oil and gas reservoir formation, including an oil shale experimental simulation chamber and a workbench. The oil shale experimental simulation chamber contains a simulated geological layer and includes a protective shell located on one side of the top of the chamber. An oil shale conveying simulation component is movably mounted on the side wall of the protective shell and can be moved to directly above the oil shale experimental simulation chamber. An oil shale screening and recovery component is located inside the protective shell. An oil shale storage component is located inside the protective shell, and the oil shale screening and recovery component is connected to the oil shale storage component. The oil shale screening and recovery component is also connected to the oil shale conveying simulation component. The top of the oil shale experimental simulation chamber is open, and the four side walls of the chamber are made of transparent material.

[0004] In existing technologies, the simulation of reservoir formation within the source is not sufficiently accurate in replicating the actual reservoir conditions, which may affect the reliability of the experimental structure. Furthermore, the distribution of oil and gas within the reservoir in different samples is difficult to control artificially, resulting in significant limitations. Summary of the Invention

[0005] This invention provides a simulation device for the effect of the number of microcracks on the efficiency of reservoir formation within the source, which overcomes the shortcomings of the prior art and can effectively solve the problem that the existing reservoir formation simulation experiments do not fully reproduce the real reservoir conditions, which may affect the reliability of the experimental structure.

[0006] The technical solution of the present invention is achieved through the following measures: a simulation device for the source-in-oil accumulation efficiency based on the number of microfractures, comprising a test platform, an experimental chamber, and a fracture-making component. The experimental chamber is fixed on the upper side of the test platform, and a loading box is placed inside the experimental chamber. The loading box stores reservoir rock samples. A borehole is vertically drilled at the center of the reservoir rock sample, and an injection mechanism is slidably connected inside the borehole. A storage tank is provided on one side of the test platform, and the storage tank is connected to the injection mechanism through a delivery pump. A pressure-applying component is provided on the upper side of the reservoir rock sample, which can compress the upper side of the reservoir rock sample. Several fracture-making components are provided circumferentially inside the reservoir rock sample, and all fracture-making components are vertically embedded in the reservoir rock sample. The fracture-making components can create fractures inside the reservoir rock sample.

[0007] The following are further optimizations and / or improvements to the above-mentioned technical solution: Preferably, the injection mechanism includes a sealing kit, a conduit, an inner tube, a drain pipe, and a side drain component. A mounting hole is provided on the loading box corresponding to the borehole position. A sealing kit is installed inside the mounting hole. A conduit is slidably installed inside the sealing kit. An inner tube is coaxially rotatably installed inside the conduit. A drain pipe is fixed below the inner tube. A permeability enhancement component is provided between the inner tube and the drain pipe. The inner tube can directly inject oil and gas into the reservoir rock sample through the permeability enhancement component. Alternatively, the inner tube can communicate with the drain pipe through the permeability enhancement component. A side drain component is fixed at the lower end of the drain pipe. The side drain component has a side drain channel. Several through holes are provided along the circumference of the conduit corresponding to the position of the side drain component.

[0008] Preferably, the antireflective component includes a shaft cylinder and a plunger. The shaft cylinder is fixedly installed on the outside of the inner tube. Multiple inner cavities are distributed circumferentially inside the shaft cylinder, and a plunger is slidably installed in each inner cavity. A drive swashplate is rotatably installed on the upper inner side of the shaft cylinder. The lower side of the drive swashplate is inclined and a sliding guide groove is provided on the lower side of the drive swashplate. The plunger is slidably connected to the sliding guide groove through a ball joint. Several side outlets are provided on the inner tube. The side outlets are unidirectionally connected to the inner cavities at corresponding positions. A side tube is installed on the lower side of each inner cavity. A circulation tube is fixed on the upper outer side of the outlet tube. The lower end of the side tube is connected to the circulation tube. Multiple jet holes are opened on the circulation tube. The guide tube at the position of the jet hole is provided with an inner hole.

[0009] Preferably, the anti-reflection component also includes a cut-off pipe, the upper part of which is slidably disposed in the inner connecting pipe, and the lower part of which is slidably disposed in the drain pipe. A ball plug is fixed inside the inner connecting pipe by a bracket. The ball plug can seal the inner side of the upper end of the cut-off pipe. A throttling ring is coaxially fixed inside the inner connecting pipe above the side drain port. A flow-stopping ring is installed on the outer side of the upper end of the cut-off pipe. The flow-stopping ring and the throttling ring have inclined surfaces that can fit and seal. A baffle is provided on the outer side of the cut-off pipe below the throttling ring. An inner spring is provided on the cut-off pipe between the baffle and the inner side of the lower end of the inner connecting pipe.

[0010] Preferably, the pressure application component includes an outer shaft frame, which is fixed on the test chamber. An inner hydraulic cylinder and an outer hydraulic cylinder are vertically fixed on the outer shaft frame, with the inner hydraulic cylinder close to the borehole. Guide rods are vertically slidably installed on the outer shaft frame, and pressure plates are fixed at the ends of the guide rods. The protruding ends of the inner and outer hydraulic cylinders are respectively fixed to the pressure plates, and the pressure plates can directly contact the upper side of the reservoir rock sample.

[0011] Preferably, the fracture-forming component includes an elastic support tube, which is vertically inserted into the reservoir rock sample. A support frame is vertically and slidably installed inside the elastic support tube. A cylindrical component is coaxially fixed on the support frame. A sleeve is elastically connected to the upper side of the cylindrical component. A support ring is coaxially provided outside the sleeve. An annular inflatable bladder is provided between the support ring and the sleeve. An inner rod is rotatably installed inside the cylindrical component. An eccentric component is fixed on the inner rod.

[0012] Preferably, the upper end of the inner rod is fixed with a pressure plate, and a stop plate is provided inside the sleeve. The upper side of the stop plate contacts the lower side of the pressure plate and has a file tooth surface structure.

[0013] Preferably, the reservoir rock samples on the outer periphery of the borehole have multiple transverse channels, and oblique channels are set between adjacent transverse channels.

[0014] The present invention has a reasonable and compact structure and is easy to use. It can inject oil and gas into reservoir rock samples using an injection mechanism, thereby artificially controlling the distribution of oil and gas and forming specific oil reservoirs. It uses a pressure application component to simulate ground pressure movement, and a fracture-forming component to assist in the formation of flow fractures in reservoir rock samples, thereby conducting multi-faceted experimental simulations. Attached Figure Description

[0015] Appendix Figure 1 This is a schematic diagram of a partial cross-sectional view of an embodiment of the present invention.

[0016] Appendix Figure 2 For the appendix Figure 1 An enlarged schematic diagram of the injection mechanism.

[0017] Appendix Figure 3 For the appendix Figure 1 A magnified structural diagram of the antireflective component in the image.

[0018] Appendix Figure 4 For the appendix Figure 3 A magnified structural diagram of point A in the diagram.

[0019] Appendix Figure 5 For the appendix Figure 1 An enlarged structural diagram of the pressure-applying component.

[0020] Appendix Figure 6 For the appendix Figure 1 An enlarged structural diagram of the seam-forming component.

[0021] The codes in the attached diagram are as follows: 1. Test chamber; 11. Delivery pump; 12. Storage tank; 13. Horizontal drain; 14. Angled drain; 2. Injection mechanism; 21. Sealing kit; 22. Conduit; 23. Internal connecting pipe; 24. Pipeline; 25. Side drain component; 26. Through hole; 3. Pressure application assembly; 31. Outer shaft bracket; 32. Inner ring hydraulic cylinder; 33. Outer ring hydraulic cylinder; 34. Guide rod; 35. Pressure plate; 4. Joint creation assembly. Components; 41. Elastic support tube; 42. Cylinder; 43. Support rod; 44. Sleeve; 45. Support ring; 46. Annular inflatable bladder; 47. Eccentric component; 48. Pressure plate; 5. Transparency enhancement component; 51. Shaft cylinder; 52. Drive swashplate; 53. Cut-off pipe; 54. Side pipe; 55. Circulation pipe; 56. Inner hole; 57. Plunger; 6. Throttling ring; 61. Ball plug; 62. Flow stop ring; 63. Side outlet; 64. Inner spring. Detailed Implementation

[0022] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0023] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0024] The present invention will be further described below with reference to embodiments and accompanying drawings: Example 1: As shown in the attached document Figures 1-6 As shown, the simulation device based on the number of microfractures affecting the reservoir formation efficiency includes a test platform, an experimental box 1, and a fracture-making component 4. The experimental box 1 is fixed on the upper side of the test platform. A loading box is placed inside the experimental box 1, which stores a reservoir rock sample. A borehole is vertically drilled at the center of the reservoir rock sample. An injection mechanism 2 is slidably connected inside the borehole. A storage tank 12 is provided on one side of the test platform. The storage tank 12 is connected to the injection mechanism 2 through a delivery pump 11. A pressure-applying component 3 is provided on the upper side of the reservoir rock sample. The pressure-applying component 3 can compress the upper side of the reservoir rock sample. Several fracture-making components 4 are arranged circumferentially inside the reservoir rock sample. All fracture-making components 4 are vertically embedded in the reservoir rock sample and can create fractures inside the reservoir rock sample.

[0025] In this invention, before conducting the reservoir accumulation simulation experiment, the injection mechanism 2 can be used to inject oil and gas into the reservoir rock sample, thereby artificially controlling the distribution of oil and gas to form homogeneous accumulation, patchy accumulation, slope accumulation, or fault accumulation. Then, the pressure application component 3 is used to simulate ground pressure movement to realize the restoration of the reservoir rock sample. The fracture-making component 4 can assist in the formation of flow fractures in the reservoir rock sample and adjust the number and development morphology of micro-fractures to conduct multi-faceted geological restoration simulation. The pumping pipe is installed on the test platform to simulate the wellbore for the movement of oil and gas. The pumping pipe can extend into the borehole, and the experimental box 1 controls the experimental temperature and humidity conditions to conduct multi-faceted experimental simulation.

[0026] The above-mentioned simulation device based on the number of microcracks to influence the efficiency of hydrocarbon accumulation within the source can be further optimized and / or improved according to actual needs: Example 2: As shown in the attached document Figure 2 , 3As shown, the injection mechanism 2 includes a sealing kit 21, a conduit 22, an inner pipe 23, a drain pipe 24, and a side drain component 25. A mounting hole is provided on the loading box corresponding to the drilling position. The sealing kit 21 is installed in the mounting hole. The conduit 22 is slidably installed inside the sealing kit 21. The inner pipe 23 is coaxially rotatably installed inside the conduit 22. A drain pipe 24 is fixed below the inner pipe 23. A permeability enhancement component 5 is provided between the inner pipe 23 and the drain pipe 24. The inner pipe 23 can directly inject oil and gas into the reservoir rock sample through the permeability enhancement component 5, or the inner pipe 23 can be connected to the drain pipe 24 through the permeability enhancement component 5. A side drain component 25 is fixed at the lower end of the drain pipe 24. The side drain component 25 has a side drain channel. Several through holes 26 are provided along the circumference of the conduit 22 corresponding to the position of the side drain component 25. The internal connecting pipe 23 can be driven to rotate by an external power device such as a motor. The internal connecting pipe 23 drives the permeability enhancement component 5, the pipe 24, and the side drain component 25 to rotate, so that oil and gas can only be injected when they are connected to the through hole 26 or the reservoir rock sample in a specific direction after passing through the internal connecting pipe 23, thereby realizing the artificial control of the oil and gas injection position.

[0027] Example 3: As shown in the attached document Figure 3 , 4 As shown, the anti-reflection component 5 includes a shaft cylinder 51 and a plunger 57. The shaft cylinder 51 is fixedly installed on the outside of the inner connecting pipe 23. The shaft cylinder 51 has multiple inner cavities distributed circumferentially inside, and the plunger 57 is slidably installed in each inner cavity. A drive swashplate 52 is rotatably installed on the upper inner side of the shaft cylinder 51. The lower side of the drive swashplate 52 is inclined, and a sliding guide groove is provided on the lower side of the drive swashplate 52. The plunger 57 is slidably connected to the sliding guide groove through a ball joint. The inner connecting pipe 23 is provided with several side outlets 63, which are unidirectionally connected to the inner cavities at corresponding positions. A side pipe 54 is installed on the lower side of each inner cavity. A circulation pipe 55 is fixed on the upper outer side of the outlet pipe 24. The lower end of the side pipe 54 is connected to the circulation pipe 55. Multiple jet holes are opened on the circulation pipe 55, and an inner hole 56 is provided on the guide pipe 21 corresponding to the position of the jet hole. When the oil and gas pressure is low, it passes through the internal connecting pipe 23 and then through the side outlet 63 into each inner cavity. The drive plate 52 rotates under the drive of the motor, and the inclined surface at the lower end of the drive plate 52 pushes the extrusion plunger 57, thereby pressurizing and sending the oil and gas to the side pipe 54 and the circulation pipe 55, and then injecting it into the reservoir rock sample through the jet hole and the inner hole 56.

[0028] Example 4: As shown in the appendix Figure 3 , 4As shown, the anti-reflection component 5 also includes a cut-off pipe 53. The upper part of the cut-off pipe 53 is slidably disposed in the inner connecting pipe 23, and the lower part of the cut-off pipe 53 is slidably disposed in the drain pipe 24. A ball plug 61 is fixed in the inner connecting pipe 23 by a bracket. The ball plug 61 can block the inner side of the upper end of the cut-off pipe 53. A throttling ring 6 is coaxially fixed in the inner connecting pipe 23 above the side drain port 63. A flow stop ring 62 is installed on the outer side of the upper end of the cut-off pipe 53. The flow stop ring 62 and the throttling ring 6 have inclined surfaces that can fit and seal. A baffle is provided on the outer side of the cut-off pipe 53 corresponding to the position below the throttling ring 6. An inner spring 64 is provided on the cut-off pipe 53 between the baffle and the inner side of the lower end of the inner connecting pipe 23. When oil and gas are transported under high pressure, the oil and gas push the cut-off pipe 53 downward, the inner spring 64 is compressed, the ball plug 61 disengages from the cut-off pipe 53 to open its upper port, and when the cut-off pipe 53 moves downward, the stop ring 62 and the throttling ring 6 seal and block the outer channel of the cut-off pipe 53, so that the oil and gas can enter the cut-off pipe 53 and flow into the drain pipe 24, and thus be transported in a direction by the side drain component 25. After the oil and gas injection is completed, the inner spring 64 pushes the cut-off pipe 53 to move upward and reset.

[0029] Example 5: As shown in the attached document Figure 5 As shown, the pressure application assembly 3 includes an outer shaft frame 31, which is fixed to the experimental chamber 1. An inner ring hydraulic cylinder 32 and an outer ring hydraulic cylinder 33 are vertically fixed on the outer shaft frame 31. The inner ring hydraulic cylinder 32 is close to the borehole. Guide rods 34 are vertically slidably mounted on the outer shaft frame 31, and pressure plates 35 are fixed to the ends of the guide rods 34. The extended ends of the inner ring hydraulic cylinder 32 and the outer ring hydraulic cylinder 33 are respectively fixed to the pressure plates 35, allowing the pressure plates 35 to directly contact the upper side of the reservoir rock sample. During ground pressure simulation, the inner ring hydraulic cylinders 32 and the outer ring hydraulic cylinders 33, positioned in a circular orientation, can apply pressure independently or in combination, thereby recreating geological conditions.

[0030] Example 6: As attached Figure 6 As shown, the fracture-forming assembly 4 includes an elastic support tube 41, which is vertically inserted into the reservoir rock sample. A support frame 43 is vertically slidably installed inside the elastic support tube 41. A cylindrical component 42 is coaxially fixed on the support frame 43. A sleeve 44 is elastically connected to the upper side of the cylindrical component 42. A support ring 45 is coaxially provided outside the sleeve 44. An annular inflatable bladder 46 is provided between the support ring 45 and the sleeve 44. An inner rod is rotatably installed inside the cylindrical component 42, and an eccentric component 47 is fixed on the inner rod. The annular inflatable bladder 46 can cause the support ring 45 to undergo elastic deformation when inflated, and it contacts the inside of the elastic support tube 41. At this time, the inner rod can generate radial vibration by the eccentric component 47 under the drive of a micro motor, thereby forming a micro fracture in the reservoir rock sample.

[0031] Example 7: As attached Figure 6As shown, a pressure plate 48 is fixed to the upper end of the inner rod, and a stop plate is provided inside the sleeve 44. The upper side of the stop plate contacts the lower side of the pressure plate 48 and has a file-tooth surface structure. The inner rod can generate axial vibration through the contact action between the pressure plate 48 and the sleeve 44 under continuous rotation, further expanding the fracture structure. By controlling the rotation speed of the inner rod and adjusting the vibration frequency and amplitude, multiple fracture-forming components can be used to form fractures within the reservoir rock sample, exhibiting different characteristics. 1. Low microfracture density: Some reservoir samples may have almost no or very few microfractures. In this case, the reservoir sample has low permeability, limited oil and gas flow capacity, and relatively low source-end hydrocarbon accumulation efficiency.

[0032] 2. Uniform microfracture distribution: Microfractures are distributed uniformly in the reservoir samples. This distribution helps improve the overall permeability and porosity of the reservoir, thereby increasing the efficiency of intrasource hydrocarbon accumulation.

[0033] 3. Concentrated Microfracture Distribution: Microfractures in reservoir samples exhibit a concentrated distribution. This means that microfractures are mainly concentrated in specific areas or strata. In these areas or strata, reservoir permeability is significantly increased, which is conducive to the accumulation and extraction of oil and gas. However, excessive microfractures can create short-circuit paths, allowing oil and gas to flow directly through these paths, bypassing other oil-bearing areas. This short-circuit effect will prevent the effective recovery of unexploited oil and gas, thereby reducing the recovery rate.

[0034] 4. Network-like microfractures: Sometimes, microfractures may exist in a network-like form, creating complex interconnected channels. In this case, the reservoir's permeability and porosity are significantly enhanced, which is beneficial for oil and gas flow and extraction, but also increases the risk of fluid leakage and loss within the reservoir. Oil and gas can escape to other areas through the microfractures and cannot be extracted or collected.

[0035] Example 8: As attached Figure 5 As shown, multiple transverse channels 13 are distributed on the outer periphery of the borehole, and oblique channels 14 are set between adjacent transverse channels 13. The distribution of oil and gas injection was adjusted according to experimental conditions to simulate common hydrocarbon accumulation patterns within oil and gas sources. Homogeneous reservoir formation: Oil and gas are evenly distributed throughout the reservoir sample, forming a homogeneous reservoir. In this case, the reservoir's permeability and pore connectivity are relatively uniform, allowing oil and gas to flow and be extracted effectively from the entire reservoir.

[0036] Patch formation: Oil and gas exist in reservoir rock samples in the form of patches. This means that oil and gas are mainly concentrated in some specific areas or patches, while other areas may have less or no oil and gas.

[0037] Slope accumulation: Slope accumulation refers to the formation of oil and gas accumulation in reservoir rock samples along slopes or inclined surfaces.

[0038] Fold formation: the morphology of oil and gas accumulation in reservoir rock samples within fold structures. In fold structures, oil and gas typically accumulate at the top of the fold or near the fold belt, forming high-yield areas.

[0039] Fault-induced hydrocarbon accumulation: Fault-induced hydrocarbon accumulation refers to the accumulation of oil and gas in reservoir rock samples due to fault activity. Faults can form migration channels for oil and gas, allowing them to move from low-permeability areas to high-permeability areas.

[0040] The specific simulation process of this invention is as follows: a representative reservoir rock sample is selected and placed in a loading box. At this time, the reservoir rock sample is preferentially drilled with boreholes, transverse channels 13 and oblique channels 14. The injection mechanism 2 extends into the borehole and injects oil and gas into the transverse channels 13 and oblique channels 14 to change the distribution pattern of oil and gas. Then, the pressure application component 3 simulates the ground pressure movement to realize the geological restoration of the reservoir rock sample. The fracture creation component 4 creates and expands the internal fractures of the reservoir rock sample to change the permeability of the reservoir rock sample. The pumping pipe is used to simulate the wellbore to transport oil and gas, and the flow rate data of oil and gas accumulation and migration are recorded.

[0041] The above technical features constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A simulation device for the effect of microfracture number on source hydrocarbon accumulation efficiency, characterized in that... The system includes a test platform, an experimental chamber, and fracture-making components. The experimental chamber is fixed on the upper side of the test platform, and a loading box is placed inside the experimental chamber. The loading box stores reservoir rock samples. A borehole is vertically drilled at the center of the reservoir rock sample, and an injection mechanism slides through the borehole. A storage tank is located on one side of the test platform, and the storage tank is connected to the injection mechanism through a delivery pump. A pressure-applying component is installed on the upper side of the reservoir rock sample, which can compress the upper side of the reservoir rock sample. Several fracture-making components are installed circumferentially inside the reservoir rock sample, and all fracture-making components are vertically embedded in the reservoir rock sample. The fracture-making components can create fractures inside the reservoir rock sample.

2. The simulation device for the effect of microfracture number on source hydrocarbon accumulation efficiency according to claim 1, characterized in that... The injection mechanism includes a sealing kit, a conduit, an inner tube, a manifold, and a side drain component. A mounting hole is provided on the loading box corresponding to the borehole position. A sealing kit is installed inside the mounting hole. A conduit is slidably installed inside the sealing kit. An inner tube is coaxially rotatably installed inside the conduit. A manifold is fixed below the inner tube. A permeability enhancement component is provided between the inner tube and the manifold. The inner tube can directly inject oil and gas into the reservoir rock sample through the permeability enhancement component, or the inner tube can communicate with the manifold through the permeability enhancement component. A side drain component is fixed at the lower end of the manifold. The side drain component has a side drain channel. Several through holes are provided along the circumference of the conduit corresponding to the position of the side drain component.

3. The simulation device for the effect of microfracture number on source hydrocarbon accumulation efficiency according to claim 2, characterized in that... The anti-reflection component includes a shaft and a plunger. The shaft is fixedly installed on the outside of the inner tube. Multiple inner cavities are distributed circumferentially inside the shaft, and a plunger is slidably installed in each inner cavity. A drive swashplate is rotatably installed on the upper inner side of the shaft. The lower side of the drive swashplate is inclined and has a sliding guide groove. The plunger is slidably connected to the sliding guide groove through a ball joint. Several side outlets are provided on the inner tube, and the side outlets are unidirectionally connected to the corresponding inner cavities. A side tube is installed on the lower side of each inner cavity. A circulation tube is fixed on the upper outer side of the outlet tube. The lower end of the side tube is connected to the circulation tube. Multiple jet holes are opened on the circulation tube, and the guide tube at the corresponding jet hole position has an inner hole.

4. The simulation device based on the effect of microfracture number on source hydrocarbon accumulation efficiency according to claim 3, characterized in that... The anti-reflection component also includes a cut-off pipe, the upper part of which is slidably disposed in the inner connecting pipe, and the lower part of which is slidably disposed in the drain pipe. A ball plug is fixed inside the inner connecting pipe by a bracket. The ball plug can seal the inner side of the upper end of the cut-off pipe. A throttling ring is coaxially fixed inside the inner connecting pipe above the side drain port. A flow stop ring is installed on the outer side of the upper end of the cut-off pipe. The flow stop ring and the throttling ring have inclined surfaces that can fit together and seal. A baffle is provided on the outer side of the cut-off pipe below the throttling ring. An inner spring is provided on the cut-off pipe between the baffle and the inner side of the lower end of the inner connecting pipe.

5. The simulation device based on the effect of microfracture number on source hydrocarbon accumulation efficiency according to claim 1, 2, 3, or 4, characterized in that... The pressure application assembly includes an outer shaft frame, which is fixed on the experimental chamber. An inner hydraulic cylinder and an outer hydraulic cylinder are vertically fixed on the outer shaft frame. The inner hydraulic cylinder is close to the borehole. Guide rods are vertically slidably installed on the outer shaft frame. A pressure plate is fixed to the end of the guide rod. The protruding ends of the inner and outer hydraulic cylinders are respectively fixed to the pressure plate. The pressure plate can directly contact the upper side of the reservoir rock sample.

6. The simulation device based on the effect of microfracture number on source hydrocarbon accumulation efficiency according to claim 1, 2, 3, or 4, characterized in that... The fracture-forming assembly includes an elastic support tube, which is vertically inserted into the reservoir rock sample. A support frame is vertically and slidably installed inside the elastic support tube. A cylindrical component is coaxially fixed on the support frame. A sleeve is elastically connected to the upper side of the cylindrical component. A support ring is coaxially installed outside the sleeve. An annular inflatable bladder is provided between the support ring and the sleeve. An inner rod is rotatably installed inside the cylindrical component. An eccentric component is fixed on the inner rod.

7. The simulation device for the effect of microfracture number on source hydrocarbon accumulation efficiency according to claim 5, characterized in that... The fracture-forming assembly includes an elastic support tube, which is vertically inserted into the reservoir rock sample. A support frame is vertically and slidably installed inside the elastic support tube. A cylindrical component is coaxially fixed on the support frame. A sleeve is elastically connected to the upper side of the cylindrical component. A support ring is coaxially installed outside the sleeve. An annular inflatable bladder is provided between the support ring and the sleeve. An inner rod is rotatably installed inside the cylindrical component. An eccentric component is fixed on the inner rod.

8. The simulation device for the effect of microfracture number on source hydrocarbon accumulation efficiency according to claim 6, characterized in that... The upper end of the inner rod is fixed with a pressure plate, and a stop plate is provided inside the sleeve. The upper side of the stop plate contacts the lower side of the pressure plate and has a file tooth surface structure.

9. The simulation device for the effect of microfracture number on source hydrocarbon accumulation efficiency according to claim 7, characterized in that... The upper end of the inner rod is fixed with a pressure plate, and a stop plate is provided inside the sleeve. The upper side of the stop plate contacts the lower side of the pressure plate and has a file tooth surface structure.

10. The simulation device based on the effect of microfracture number on intrasource hydrocarbon accumulation efficiency according to claim 1, 2, 3, 4, 7, 8, or 9, characterized in that... Multiple transverse channels are distributed in the reservoir rock samples on the outer periphery of the borehole, and oblique channels are set between adjacent transverse channels.

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