CN114412417B

CN114412417B - Multi-stage coalbed methane combined production experimental device

Info

Publication number: CN114412417B
Application number: CN202011169883.0A
Authority: CN
Inventors: 孙斌; 田文广; 杨敏芳; 杨青; 祁灵
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2020-10-28
Filing date: 2020-10-28
Publication date: 2024-03-26
Anticipated expiration: 2040-10-28
Also published as: CN114412417A

Abstract

The invention provides a multi-stage coalbed methane combined production experimental device, which comprises: the oil-gas reservoir experimental cabin body is provided with a plurality of coal seam experimental cabins; the multi-channel type shaft is arranged in the oil and gas reservoir experimental cabin body along the up-down direction, the multi-channel type shaft is provided with a plurality of production shafts which are distributed inside and outside, the production shafts are communicated with the coal seam experimental cabins in a one-to-one correspondence manner, and the central production shaft is communicated with the coal seam experimental cabin on the top layer; a production string disposed within the central production wellbore; a shaft tail tube for storing oil, which is arranged at the lower end of the multi-channel shaft; and the tail tube power mechanism is arranged on the tail tube of the shaft and connected with the central production shaft, and is used for driving oil in the tail tube of the shaft to flow into the central production shaft. The invention relieves the technical problems of poor simulation reality of the simulation experiment device and larger error of the experiment result in the research of coal bed gas exploitation.

Description

Multi-stage coalbed methane combined production experimental device

Technical Field

The invention relates to the field of coalbed methane combined production, in particular to a multi-stage coalbed methane combined production experimental device.

Background

The coalbed methane is hydrocarbon gas which is stored in the coalbed and takes methane as a main component, takes the surface of coal matrix particles as a main component, and is partially dissociated in coal pores or dissolved in the coalbed water, is the associated mineral resource of coal, belongs to unconventional natural gas, and is clean, high-quality energy and chemical raw materials. In coal mining, the coalbed methane reserves are large, the existing well patterns can be utilized to the maximum extent by multi-stage coalbed methane combined mining, the development cost is saved, and the method is a main development trend of coalbed methane development.

Under factors such as actual coal industry exploitation geological conditions, geographical position, etc., technical researchers are inconvenient to further observe and research resource development and utilization in the industry field, so that simulation experiments are generally adopted for observation and research, but at present, the simulation reality of a simulation experiment device is poor, and the experimental result has larger error.

Disclosure of Invention

The invention aims to provide a multi-stage coalbed methane combined mining experimental device so as to solve the technical problems that simulation experimental devices in research of coalbed methane mining are poor in simulation reality and large in error of experimental results.

The above object of the present invention can be achieved by the following technical solutions:

the invention provides a multi-stage coalbed methane combined production experimental device, which comprises:

the oil-gas reservoir experiment cabin body is provided with a plurality of coal seam experiment cabins for loading coal samples, and the plurality of coal seam experiment cabins are distributed up and down;

the multi-channel type shaft is arranged in the oil-gas reservoir experimental cabin body along the up-down direction, a plurality of production shafts which are distributed inside and outside are arranged in the multi-channel type shaft, the production shafts are communicated with the coal seam experimental cabins in a one-to-one correspondence manner, and the central production shaft is communicated with the coal seam experimental cabin on the top layer;

a production string disposed within the production wellbore at a center;

a shaft tail tube for storing oil, which is arranged at the lower end of the multi-channel shaft;

and the tail tube power mechanism is arranged on the tail tube of the shaft and connected with the central production shaft, and is used for driving oil in the tail tube of the shaft to flow into the central production shaft.

In a preferred embodiment, the tail pipe power mechanism comprises a screw mechanism.

In a preferred embodiment, the tail pipe power mechanism comprises a one-way circulation device connected to the upper end of the screw mechanism, the screw mechanism being in communication with the central production well bore through the one-way circulation device, the one-way circulation device allowing oil to flow from the screw mechanism to the central production well bore and preventing oil from flowing from the central production well bore to the screw mechanism.

In a preferred embodiment, the hydrocarbon reservoir experimental capsule has a first sidewall and a second sidewall perpendicular to the X-axis, and a third sidewall and a fourth sidewall perpendicular to the Y-axis; the multi-stage coalbed methane combined production experimental device comprises an experimental cabin confining pressure device, wherein the experimental cabin confining pressure device comprises an X-direction confining pressure mechanism and a Y-direction confining pressure mechanism; the X-direction confining pressure mechanism comprises an X fixed block, an X moving block and an X-direction driving mechanism, wherein the X fixed block is in butt joint with the first side wall, the X moving block is in butt joint with the second side wall, and the X-direction driving mechanism is connected with the X moving block and is used for driving the X moving block to move towards the X fixed block; the Y-direction confining pressure mechanism comprises a Y fixed block, a Y movable block and a Y-direction driving mechanism, wherein the Y fixed block is in butt joint with the third side wall, the Y movable block is in butt joint with the fourth side wall, and the Y-direction driving mechanism is connected with the Y movable block and is used for driving the Y movable block to move towards the Y fixed block.

In a preferred embodiment, sealing cover plates are respectively arranged at the top of each layer of coal seam experimental cabin, the sealing cover plates can move up and down in the oil and gas reservoir experimental cabin, and the multi-channel shaft is inserted into each sealing cover plate and fixedly connected with each sealing cover plate; the multi-stage coalbed methane combined production experimental device comprises a lower pressurizing device, wherein the lower pressurizing device is connected with the multi-channel type shaft and can drive the multi-channel type shaft to move up and down.

In a preferred embodiment, the lower pressurizing device comprises a piston cavity, a sealing ring piston and an oil supply mechanism, the tail tube of the shaft is fixedly connected with the multi-channel shaft, the tail tube of the shaft is installed in the piston cavity through the sealing ring piston, and the oil supply mechanism can convey oil to a space above the sealing ring piston in the piston cavity.

In a preferred embodiment, the multi-stage coalbed methane combined production experimental device comprises a hydraulic cylinder fixedly arranged above the oil-gas reservoir experimental cabin, and a piston rod of the hydraulic cylinder is abutted with the sealing cover plate of the top layer.

In a preferred embodiment, the multi-stage coalbed methane co-production experimental device comprises an oil supply barrel, wherein the oil supply barrel can supply oil to the tail pipe of the shaft; the top of each production pit shaft is equipped with the production export, and each the production export is connected with oil gas pipe control box through the oil pipe pipeline respectively, oil gas pipe control box can carry out the gas-liquid separation, the fluid after the oil gas pipe control box separation can be carried to the oil feed bucket.

In a preferred embodiment, the production wellbore is connected to the coal seam test pod by a production connection hole, the production connection hole comprising a flared portion that gradually enlarges from the production wellbore toward the coal seam test pod.

In a preferred embodiment, the multi-channel wellbore is manufactured using additive manufacturing.

In a preferred embodiment, the hydrocarbon reservoir experimental capsule comprises 3 coal seam experimental capsules, and the multi-channel well bore comprises 3 production well bores.

The invention has the characteristics and advantages that:

filling coal samples into each coal bed experimental cabin, and simulating a coal bed reservoir of the coal bed gas of the reservoir by a plurality of coal sample layers distributed up and down; the multi-channel well bore with a plurality of production well bores distributed inside and outside simulates the well bores in actual development and production, and the production well bores are communicated with the coal sample layers in a one-to-one correspondence manner, so that higher production efficiency can be achieved. The coalbed methane stored in the coal sample layer enters a corresponding production shaft and is discharged upwards; and for the central production shaft, the tail shaft power mechanism sends oil in the tail shaft of the shaft into the central production shaft, and the production pipe column is used for exploiting oil and coal bed gas. The multi-stage coalbed methane combined production experimental device is used for experiments, can accurately simulate multi-stage coalbed methane combined production, has higher simulation fidelity, and reduces errors of experimental results.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is an isometric view of a multi-stage coalbed methane combined production experimental device provided by the invention;

FIG. 2 is a cross-sectional view of a multi-stage coalbed methane combined production experimental device provided by the invention;

FIG. 3 is a schematic view of a multi-channel wellbore in the multi-stage coalbed methane co-production experimental apparatus shown in FIG. 2;

FIG. 4 is a schematic structural view of a tail pipe power mechanism in the multi-stage coalbed methane combined production experimental device shown in FIG. 2;

FIG. 5 is a schematic structural diagram of a unidirectional flow device in the multi-stage coalbed methane co-production experimental device shown in FIG. 2;

FIG. 6 is a schematic diagram of a production string in the multi-stage coalbed methane co-production experimental apparatus shown in FIG. 2;

fig. 7 is a schematic structural diagram of an experimental cabin confining pressure device in the multi-stage coalbed methane combined production experimental device shown in fig. 2.

Reference numerals illustrate:

13. an oil-gas reservoir experimental cabin body; 131. an X axis; 132. a Y axis;

130. the coal seam experiment cabin; 64. the primary coal seam experiment cabin; 68. the secondary coal seam experiment cabin; 47. three-level coal seam experiment cabins;

133. sealing the cover plate; 65. a primary coal seam separator plate; 69. a secondary coal seam separator plate; 48. a top layer sealing cover plate;

63. a bottom layer fixing plate; 201. a circular ring pressing plate;

11. a multi-channel wellbore;

111. a production wellbore; 39. an inner wellbore; 40. a middle layer shaft; 41. an outer wellbore;

30. sealing the annular space; 32. sealing the annular space; 34. sealing the annular space;

112. a production outlet; 36. a first pipe interface; 37. a second pipeline interface; 38. a third pipeline interface; 7. a flow meter; 10. a flow meter; 12. a flow meter;

113. producing a connecting hole; 1131. a flare part; 31. a first production connection hole; 33. a second production connection hole; 35. a third production connection hole;

114. a production string; 49. a production tubing; 50. a safety valve; 51. a cable packer; 52. a cable; 54. an oil drain valve; 55. a single flow valve; 56. an electric pump; 57. a separator; 58. an electrical protector; 59. a motor; 60. a centralizer; 61. an electric submersible pump;

46. a composite sealing strip; 62. an O-compound seal;

45. a wellbore tail; 44. a tail tube power mechanism;

43. a screw mechanism; 249. a servo motor; 246. a coupling; 248. a screw; 247. a connecting column; 250. sealing the connection member; 251. a connecting piece;

42. a unidirectional flow-through device; 242. an O-shaped sealing ring; 241. a pellet; 239. a spring; 240. a connecting piece; 238. a fixing member; 237. fixing the bolt; 243. a tube body; 244. an oil inlet; 245. oil outlet

200. The experimental cabin confining pressure device;

2001. an X-direction confining pressure mechanism; 229. x fixed blocks; 234. an X moving block;

2003. an X-direction driving mechanism; 226. an X rotating shaft; 236. an X base; 235. an X-block; 227. an X coupling; 228. an X servo motor;

2002. y-direction confining pressure mechanism; 230. a Y fixed block; 225. a Y moving block;

2004. a Y-direction driving mechanism; 231. a Y rotating shaft; 224. a Y base; 223. a Y-block; 233. a Y coupling; 232. a Y servo motor;

202. a lower pressurizing device; 203. a piston chamber; 205. a seal ring piston;

2020. an oil supply mechanism; 204. a space; 206. a pipeline; 207. a control valve; 208. a control valve; 209. a pipeline; 210. a movable rod; 211. a piston; 222. a space;

8. a hydraulic cylinder; 6. a hydraulic cylinder bracket; 9. a hydraulic cylinder connection;

14. a signal lamp; 16. a matrix keyboard; 17. a main controller; 4. a pipeline control box; 24. an auxiliary material control box; 29. an experiment table;

22. an oil supply barrel; 15. an oil gas pipe control box; 21. an oil supply line; 23. an oil return pipeline;

26. a gas supply tank; 25. an air supply line; 67. a pipeline; 71. a pipeline; 73. a pipeline; 66. an electromagnetic valve; 70. an electromagnetic valve; 72. an electromagnetic valve; 27. an exhaust fan;

18. a first-stage gas collecting bottle; 19. a secondary gas collecting bottle; 20. three-stage gas collecting cylinders;

1. an air extracting pump; 2. an oil pump; 3. an electric control box; 5. a junction box; 28. a bottom cabinet; 29. an experiment table.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention provides a multi-stage coalbed methane combined production experimental device, which is shown in fig. 1 and 2, and comprises an oil-gas reservoir experimental cabin body 13, a multi-channel shaft 11, a production tubular column 114, a shaft tail tube 45 and a tail tube power mechanism 44, wherein the oil-gas reservoir experimental cabin body 13 is provided with a plurality of coal bed experimental cabins 130 for loading coal samples, and the plurality of coal bed experimental cabins 130 are distributed up and down; the multi-channel type shaft 11 is arranged in the oil and gas reservoir experimental cabin 13 along the up-down direction, the multi-channel type shaft 11 is provided with a plurality of production shafts 111 which are distributed inside and outside, the production shafts 111 are communicated with the coal seam experimental cabins 130 in a one-to-one correspondence manner, and the central production shaft 111 is communicated with the coal seam experimental cabin on the top layer; a production tubing string 114 is disposed within the central production wellbore 111; the tail shaft 45 is used for storing oil, and the tail shaft 45 is arranged at the lower end of the multi-channel shaft 11; the tail pipe power mechanism 44 is mounted on the tail pipe 45 of the shaft and is connected with the central production shaft 111 for driving oil in the tail pipe 45 of the shaft to flow into the central production shaft 111.

Filling coal samples into each coal seam experiment cabin 130, and simulating a coal seam reservoir of the coal seam gas of the reservoir by a plurality of coal sample layers distributed up and down; the multi-channel well bore 11 with the plurality of production well bores 111 distributed inside and outside simulates the well bores in actual development and production, and the plurality of production well bores 111 are communicated with the plurality of coal sample layers in a one-to-one correspondence manner, so that high production efficiency can be achieved. The coalbed methane stored in the coal sample layer enters the corresponding production shaft 111 and is discharged upwards; in the central production well bore 111, the tail pipe power mechanism 44 feeds the oil in the tail pipe of the well bore into the central production well bore 111, and the production pipe column 114 produces the oil and the coalbed methane. The multi-stage coalbed methane combined production experimental device is used for experiments, can accurately simulate multi-stage coalbed methane combined production, has higher simulation fidelity, and reduces errors of experimental results.

The number of the coal seam experiment cabins 130 in the oil and gas reservoir experiment cabin 13 can be one or more; preferably, as shown in fig. 2 and 3, the hydrocarbon reservoir experimental capsule 13 includes 3 coal seam experimental capsules 130 and the multi-channel wellbore 11 includes 3 production wellbores 111. As shown in fig. 2, the plurality of coal seam test cabins 130 are a primary coal seam test cabin 64, a secondary coal seam test cabin 68 and a tertiary coal seam test cabin 47 from bottom to top, respectively. As shown in fig. 1 to 3, the production bores 111 are an outer bore 41, a middle bore 40, and an inner bore 39 from outside to inside, and the inner bore 39 is the central production bore 111. Preferably, the outer wellbore 41, the middle wellbore 40, and the inner wellbore 39 are coaxially disposed. Wherein a closed annular space 30 is formed between the outer wellbore 41 and the middle wellbore 40; a closed annular space 32 is formed between the middle layer well bore 40 and the inner layer well bore 39; the closed space of the pipeline inside the inner layer shaft 39 is a closed annular space 34.

The top of each production well bore 111 is provided with a production outlet 112, as shown in fig. 3, a first line interface 36, a third line interface 38 and a second line interface 37, respectively. The oil pipe lines of the first pipe line interface 36, the second pipe line interface 37 and the third pipe line interface 38 are respectively provided with a flowmeter 7, a flowmeter 10, a flowmeter 12 and a control valve, well flow information in the pipeline is monitored in real time, monitoring data information is dynamically displayed on a display screen of the main controller 17 in real time, and experimental running state information is obtained.

The multi-stage coalbed methane combined production experimental device comprises an oil supply barrel 22, wherein the oil supply barrel 22 can supply oil to a shaft tail tube 45. The top end of the oil supply barrel 22 is provided with an oil supply pipeline 21 and an oil return pipeline 23, the oil supply pipeline 21 and the oil return pipeline 23 are respectively provided with a pipeline control valve, and oil supply is provided for the shaft tail tube 45 through a pipeline control box 4 under the control of the main controller.

The multi-stage coalbed methane combined mining experimental device comprises a gas supply tank 26, wherein the top end of the gas supply tank 26 is connected with a gas supply pipeline 25, and a gas circuit control valve is designed on the gas supply pipeline 25. As shown in fig. 2, each coal seam experiment compartment is provided with a pipeline 67, a pipeline 71 and a pipeline 73; the output ports of the pipeline 67, the pipeline 71 and the pipeline 73 are respectively communicated with the primary coal seam experimental cabin 64, the secondary coal seam experimental cabin 68 and the tertiary coal seam experimental cabin 47.

The side part of the oil-gas reservoir experiment cabin 13 is respectively connected with the output ports of the pipeline 67, the pipeline 71 and the pipeline 73. The output ports of the pipeline 67, the pipeline 71 and the pipeline 73 are respectively communicated with the primary coal seam experimental cabin 64, the secondary coal seam experimental cabin 68 and the tertiary coal seam experimental cabin 47; the other output ends of the line 67, the line 71 and the line 73 are connected to the line control box 4. The air supply pipeline 25 is communicated with the primary coal seam experimental cabin 64, the secondary coal seam experimental cabin 68 and the tertiary coal seam experimental cabin 47 respectively through a pipeline 67, a pipeline 71 and a pipeline 73 which are connected to the pipeline control box 4. The pipeline control box 4 is connected with an air supply tank 26 through an air supply pipeline 25 and an air passage control valve, and the air supply tank 26 supplies air sources of all coal seam experiment cabins in the oil-gas reservoir experiment cabin body 13 under the control of the main controller 17.

Further, the electromagnetic valve 66, the electromagnetic valve 70 and the electromagnetic valve 72 are respectively arranged on the pipeline 67, the pipeline 71 and the pipeline 73, and the supply of the gas in the experimental cabins of different coal beds is realized by controlling the on-off of the electromagnetic valve 66, the electromagnetic valve 70 and the electromagnetic valve 72 under the control of intelligent system parameters of the main controller 17.

In one embodiment of the invention, the oil-gas reservoir experimental cabin 13 is connected with an auxiliary material control box 24, and the auxiliary material control box 24 controls and supplies the well liquid composition resources such as water, coal samples and the like in the oil-gas reservoir experimental cabin 13.

As shown in fig. 6, the production string includes an electric submersible pump 61, a centralizer 60, an electric protector 58, a separator 57, an electric pump 56, a single flow valve 55, a drain valve 54, a cable packer 51, a safety valve 50, a production tubing 49, a motor 59, and a cable 52. When the electric submersible pump 61 rotates at a high speed, the liquid filled in the impeller is thrown to the periphery along the vane flow passage under the action of centrifugal force, and the well liquid is lifted to the top outlet by overlapping the liquid pressure energy step by step.

In one embodiment of the present invention, the tail tube power mechanism 44 includes a screw mechanism 43, and the screw mechanism 43 includes a servo motor 249, a coupling 246, a screw 248, a connecting cylinder 247, a sealing connection 250, and a connection 251. As shown in fig. 4, the servo motor 249 is connected to the screw 248 via the coupling 246. The motor drives the screw 248 to rotate, the periphery of the helical blade on the screw 248 is filled with oil, and when the screw 248 rotates at a high speed, the oil is lifted up along the first stage of the helical shaft under the action of the helical blade on the screw 248 until reaching the oil outlet 245 of the unidirectional flow device 42. The unidirectional flow device 42 is designed to realize the unidirectional flow of the oil flow and prevent the reverse flow of the oil flow.

Further, as shown in fig. 4, the tail pipe power mechanism 44 includes a one-way circulation device 42, the one-way circulation device 42 being connected to an upper end of the screw mechanism 43, the screw mechanism 43 being in communication with the central production wellbore 111 through the one-way circulation device 42, the one-way circulation device allowing oil to flow from the screw mechanism 43 to the central production wellbore 111 and preventing oil from flowing from the central production wellbore 111 to the screw mechanism 43. The structure design of the unidirectional flow device realizes the unidirectional flow of the oil flow and prevents the reverse flow of the oil flow.

As shown in fig. 5, the tube 243 in the unidirectional flow device 42 has a hollow tubular structure, wherein an O-ring 242 is disposed at the inner diameter of the thin opening in the tube 243, a bead 241 is disposed on the O-ring 242, and a connecting member 240 having a profile of the bead 241 is disposed on the bead 241 and is in partial spherical contact with the bead 241. The fixing bolt 237 passes through the fixing piece 238 with a pin hole, and two ends of the fixing bolt 237 are in interference fit with the fixing piece 238 and the pipe body 243, so that the fixing effect on the fixing piece 238 is realized. Both the connecting member 240 and the fixing member 238 are designed with cylindrical recesses of the same outer diameter as the springs. The spring 239 is disposed at its opposite ends in the cylindrical recesses of the connecting member 240 and the fixing member 238, respectively. In the unidirectional flow device 42, when the oil flows in from the oil inlet 244, the ball 241 is lifted up by the expansion and contraction action of the spring 239, and when the oil flows in from the oil inlet 244, the oil flows out from the oil outlet 245. When the oil flow reversely flows from the position of the oil outlet 245, the small ball 241 is in sealing connection with the O-shaped sealing ring 242. The structural design of the unidirectional flow device 42 realizes the function of unidirectional flow of the oil flow and preventing the reverse flow of the oil flow.

The tail pipe power mechanism 44 sequentially passes through the center position of the bottom of the outer layer shaft 41, the center position of the closed annular space 30 and the center position of the middle layer shaft 40 from the shaft tail pipe 45. The oil inlet 244 of the unidirectional flow device 42 is connected to the screw mechanism 43 by a connecting cylinder 247 on the screw mechanism 43 and a sealing connection 250. An oil outlet 245 in the unidirectional flow device 42 is connected with the connector 251. An oil outlet 245 and a connecting piece 251 of the unidirectional flow device 42 in the tail pipe power mechanism 44 are positioned at the upper end of the bottom center of the middle layer shaft 40, and a bottom position in the closed annular space 32 is closed. The lower end of the screw mechanism 43 in the closed annular space 32 is connected with a connecting piece 251 on the tail tube power mechanism 44, and the upper end of the screw mechanism 43 is connected with an oil inlet 244 of the unidirectional flow device 42 through a sealing connecting piece 250 on the screw mechanism 43. An oil outlet 245 of one-way flow device 42 is located within closed annular space 34 and one-way flow device 42 is located within closed annular space 32. The screw mechanism 43 is driven by the power of the servo motor 249 to rotate, so that the screw mechanism 43 and the unidirectional flow device 42 connected with the upper end of the screw mechanism are driven to rotate.

Further, sealing bearings are designed at the bottoms of the inner layer shaft 39, the middle layer shaft 40 and the outer layer shaft 41 and at the connecting parts contacted with the tail shaft power mechanism 44, the screw mechanism 43 and the unidirectional circulating device 42, so that sealing of different airtight annular spaces is realized, and interlayer gas-liquid interference is prevented. In the multi-channel wellbore 11, the oil in the closed annular space 30, the closed annular space 32, and the closed annular space 34 flows upward into the inner wellbore 39 through the screw mechanism 43 and the one-way circulation device 42.

Preferably, in the multi-channel well bore 11, the bottoms of the outer well bore 41, the middle well bore 40 and the inner well bore 39 are respectively provided with a one-way circulation device 42, and a well liquid extraction runner is from bottom to top to prevent backflow and influence on experimental results. To promote versatility, the unidirectional flow-through devices 42 are the same size.

As shown in fig. 1, 2 and 7, the hydrocarbon-bearing experimental tank 13 has a rectangular parallelepiped shape, and the hydrocarbon-bearing experimental tank 13 has a first side wall and a second side wall perpendicular to the X axis 131, and a third side wall and a fourth side wall perpendicular to the Y axis 132; the multi-stage coalbed methane combined production experimental device comprises an experimental cabin confining pressure device, wherein the experimental cabin confining pressure device comprises an X-direction confining pressure mechanism 2001 and a Y-direction confining pressure mechanism 2002; the X-direction confining pressure mechanism 2001 comprises an X-direction fixed block 229, an X-direction moving block 234 and an X-direction driving mechanism 2003, wherein the X-direction fixed block 229 is abutted against the first side wall, the X-direction moving block 234 is abutted against the second side wall, and the X-direction driving mechanism 2003 is connected with the X-direction moving block 234 and is used for driving the X-direction moving block 234 to move towards the X-direction fixed block 229; the Y-direction confining pressure mechanism 2002 includes a Y-direction fixed block 230, a Y-direction movable block 225, and a Y-direction driving mechanism 2004, wherein the Y-direction fixed block 230 abuts against the third side wall, the Y-direction movable block 225 abuts against the fourth side wall, and the Y-direction driving mechanism 2004 is connected to the Y-direction movable block 225 for driving the Y-direction movable block 225 to move toward the Y-direction fixed block 230. The second and fourth sidewalls may be hard non-slip rubber plates, and the second and fourth sidewalls may be deformed by the pushing of the X and Y moving blocks 234 and 225, respectively, to apply confining pressure.

Specifically, the X-direction drive mechanism includes an X-axis 226, an X-base 236, an X-stop 235, an X-coupling 227, and an X-servo motor 228; the Y-direction drive mechanism includes a Y-axis 231, a Y-base 224, a Y-stop 223, a Y-coupler 233, and a Y-servo motor 232.

The X fixed block 229 is fixedly connected with the X base 236 by screw locking, the X base is provided with a through threaded hole and a through hole in the X direction, the X moving block 234 is provided with a threaded hole, the bottom of the X moving block 234 is internally arranged at the central groove of the X base 236, one end of the X rotating shaft 226 is an optical axis, and the other end is provided with external threads. The X rotation shaft 226 has a through screw hole and a through hole in the X direction through the X base, and the X moving block 234 has a screw hole. One end of the X rotating shaft 226, which is provided with external threads, is connected with an X blocking piece 235, and one end of the optical axis is connected with an X servo motor 228 through an X coupler 227. The X servo motor 228 realizes forward and reverse rotation under the instruction of the main controller, and drives the X rotating shaft 226 to rotate forward and reverse under the rotation action of the X servo motor 228 so as to realize the reciprocating movement of the X moving block 234 in the X direction.

The Y fixed block 230 is fixedly connected with the Y base 224 by screw locking, the Y base 224 is provided with a through threaded hole and a through hole in the Y direction, the bottom of the Y moving block 225 provided with the threaded hole Y moving block 225 is internally arranged at the central groove of the Y base 224, one end of the Y rotating shaft 231 is an optical axis, and the other end is provided with external threads. The Y-axis 231 has a through-screw hole and a through-hole in the Y-direction through the Y-base, and the Y-moving block 225 has a screw hole. One end of the Y rotating shaft 231, which is provided with external threads, is connected with the Y blocking piece 223, and one end of the optical axis is connected with the Y servo motor 232 through the Y coupler 233. The Y servo motor 232 is instructed by the main controller to realize forward and reverse rotation, and the Y rotating shaft 231 is driven to rotate forward and reverse under the rotation action of the Y servo motor 232 to realize the reciprocating movement of the Y moving block 225 in the Y direction.

The oil-gas reservoir experiment cabin 13 is arranged in a rectangular space formed by the X fixed block 229, the X base 236, the X movable block 234, the Y fixed block 230, the Y base 224 and the Y movable block 225, so that the peripheral pressure control function of the oil-gas reservoir experiment cabin 13 is realized.

In an embodiment of the present invention, the top of each layer of coal seam experiment cabin 130 is respectively provided with a sealing cover plate 133, the sealing cover plates 133 can move up and down in the oil and gas reservoir experiment cabin 13, and the multi-channel shaft 11 is inserted into each sealing cover plate 133 and fixedly connected with each sealing cover plate 133. As shown in fig. 2, each seal cover plate 133 is a primary seam splitter plate 65, a secondary seam splitter plate 69, and a top seal cover plate 48, respectively, from bottom to top. The oil and gas reservoir experiment cabin 13 is also provided with a bottom layer fixing plate 63. In the oil-gas reservoir experiment cabin body 13, a primary coal seam experiment cabin 64 is formed between a primary coal seam partition plate 65 and a bottom layer fixing plate 63; a secondary coal seam experiment cabin 68 is formed between the primary coal seam partition plate 65 and the secondary coal seam partition plate 69; a third-level coal seam test chamber 47 is formed between the second-level coal seam divider 69 and the top-level seal cover 48. The primary coal seam experimental cabin 64, the secondary coal seam experimental cabin 68 and the tertiary coal seam experimental cabin 47 are respectively provided with a primary coal seam coal sample, a secondary coal seam coal sample and a tertiary coal seam coal sample.

The primary coal seam separating plate 65, the secondary coal seam separating plate 69, the top sealing cover plate 48 and the bottom fixing plate 63 are all rectangular in shape, and circular through holes are formed in the centers of the rectangles. The multi-channel shaft 11 passes through the round hole, and sequentially passes through the top sealing cover plate 48, the primary coal seam partition plate 65, the secondary coal seam partition plate 69 and the bottom fixing plate 63 from the top of the oil-gas reservoir experiment cabin body 13. To enhance versatility, the inside diameter of each circular through hole is the same size as the outside diameter of the multi-channel wellbore 11.

In an embodiment of the present invention, the multi-stage coalbed methane co-production experimental device includes a lower pressurizing device 202, where the lower pressurizing device 202 is connected to the multi-channel well bore 11, and can drive the multi-channel well bore 11 to move up and down, so as to drive the sealing cover plate 133 to move up and down.

As shown in fig. 2, the lower pressurizing device 202 includes a piston chamber 203, a seal ring piston, and an oil supply mechanism 2020, the wellbore tail is fixedly connected to the multi-channel wellbore 11, the wellbore tail is mounted in the piston chamber 203 through the seal ring piston, and the oil supply mechanism 2020 can supply oil to a space above the seal ring piston in the piston chamber 203. The oil supply mechanism 2020 drives the multi-channel type shaft 11 to move downwards together under the action of the pressure difference between the inner oil and the outer oil, and simultaneously drives the multi-channel type shaft 11 to move downwards, so that the pressure in the experiment cabin is applied.

Specifically, the seal ring piston 205 is in sliding contact with the interior of the piston chamber 203, and the bottom extension of the multi-channel wellbore 11, the wellbore tail 45, and the seal ring piston 205 are sealingly designed within the piston chamber 203 in the lower pressurization device 202.

Opening the control valve 208, closing the control valve 207, lifting the movable rod 210 upwards while the piston 211 in the space 222 is lifted, and at this time, injecting the oil in the space 204 into the space 222 through the pipeline 209; the control valve 208 is closed, the control valve 207 is opened, the movable rod 210 is pulled downwards, at this time, along with the downward movement of the piston 211, the oil injected into the previous space 222 flows into the piston cavity 203 through the pipeline 206, and under the action of the downward pressure, the sealing ring piston 205 drives the multi-channel type shaft 11 to move downwards together, and simultaneously drives the annular pressing plate 201 arranged on the multi-channel type shaft 11 to move downwards, so that the pressure of the experimental cabin is exerted. Preferably, the multi-channel well bore 11 is provided with a circular ring pressure plate 201 on the outer wall of each laboratory chamber section.

In an embodiment of the invention, the multi-stage coalbed methane combined production experimental device comprises an upper pressurizing device, wherein the upper pressurizing device comprises a hydraulic cylinder fixedly arranged above the oil-gas reservoir experimental cabin 13, and a piston rod of the hydraulic cylinder is abutted with a sealing cover plate 133 of the top layer.

Specifically, the upper pressurizing device further includes a cylinder bracket 6 and a cylinder connector 9. As shown in fig. 2, the hydraulic cylinder support 6 is arranged on the experiment table 29, and the hydraulic cylinder support 6, the hydraulic cylinder 8 and the hydraulic cylinder connecting piece 9 are sequentially connected downwards to form an assembly. The top of the hydraulic cylinder connecting piece 9 is designed into a rectangle, the hydraulic cylinder 8 is connected to the center of the rectangle, four points of the rectangle are respectively designed with a quadrangular extending end, and the end face of the extending end is contacted with a top layer sealing cover plate 48 on the top layer of the oil-gas reservoir experiment cabin 13. The design of the appearance structure of the hydraulic cylinder connecting piece 9 is beneficial to the uniform distribution of pressure on the oil-gas reservoir experiment cabin 13 when the hydraulic cylinder 8 is pressed down in the experimental operation process, and reduces the experimental error of the simulation experiment device.

In one embodiment of the present invention, each production outlet 112 is connected to the oil-gas pipe control box 15 through an oil pipe, the oil-gas pipe control box 15 can perform gas-liquid separation, and the separation of gas and liquid is achieved through the oil-gas pipe control box 15: the separated gas is led into a first-stage gas collecting bottle 18, a second-stage gas collecting bottle 19 and a third-stage gas collecting bottle 20 through pipelines; the separated oil can be transferred to the oil supply tub 22. The primary gas collecting bottle 18, the secondary gas collecting bottle 19 and the tertiary gas collecting bottle 20 are connected with the oil gas pipe control box 15 through pipelines, the pipelines are connected with the air pump 1, and the air pump 1 provides power to drive the separated gas to flow; the separated gas can flow into the first-stage gas collection bottle 18, the second-stage gas collection bottle 19 and the third-stage gas collection bottle 20 to serve as standby gas collection bottles, and after the first-stage gas collection bottle 18 is filled, the gas flows into the second-stage gas collection bottle 19 and the third-stage gas collection bottle 20 in sequence.

The well fluid in the production oil pipe 49 is pumped out of the well surface under the power drive of the oil pump 2, and is conveyed to the oil-gas pipe control box 15 through oil pipe pipelines respectively connected with the first pipeline interface 36, the second pipeline interface 37 and the third pipeline interface 38, and after gas-liquid separation is carried out in the oil-gas pipe control box 15, the oil fluid circularly flows into the oil supply barrel 22 through the oil return pipeline 23, so that the recycling is realized. The oil return pipeline 23 is connected with an oil pump 2, and the oil pump 2 provides power to enable oil to flow to the oil supply barrel 22.

In one embodiment of the present invention, the production wellbore 111 is connected to the coal seam test pod 130 via a production connection hole 113, the production connection hole 113 including a flared portion 1131, the flared portion 1131 gradually expanding from the production wellbore 111 toward the coal seam test pod. The horn-shaped outer port of the horn mouth 1131 is designed, so that the contact surface is increased, and the coal bed gas collection efficiency is effectively improved; effectively replace traditional multilayer annular ring design, promote airtight space air tightness.

Specifically, first production connecting holes 31 are circumferentially and uniformly distributed on the lower circumferential outer wall of the outer layer shaft 41, the first production connecting holes 31 are production connecting holes 113 for connecting the outer layer shaft 41 with the coal seam experimental cabin 130, the inner ports of the first production connecting holes 31 are communicated with the closed annular space 30, the horn-shaped outer ports of the first production connecting holes 31 are positioned in the primary coal seam experimental cabin 64, wherein the horn-shaped outer ports of the first production connecting holes 31 are connected with vent holes arranged on the primary coal seam coal sample in the primary coal seam experimental cabin 64

Second production connecting holes 33 are uniformly distributed on the circumference of the middle circumference outer wall of the middle shaft 40, the second production connecting holes 33 are production connecting holes 113 for connecting the middle shaft 40 and the coal seam experimental cabin 130, the second production connecting holes 33 penetrate through the airtight annular space 30, the inner ports of the second production connecting holes 33 are communicated with the airtight annular space 32, the horn-shaped outer ports of the second production connecting holes 33 are positioned in the secondary coal seam experimental cabin 68, and the horn-shaped outer ports of the second production connecting holes 33 are connected with vent holes arranged on a secondary coal seam coal sample in the secondary coal seam experimental cabin 68.

Third production connecting holes 35 are uniformly distributed on the circumference of the outer wall of the upper part of the inner layer shaft 39, the third production connecting holes 35 are production connecting holes 113 for connecting the inner layer shaft 39 with the coal seam experimental cabin 130, the third production connecting holes 35 penetrate through the airtight annular space 30 and the airtight annular space 32, the inner ports of the third production connecting holes 35 are communicated with the airtight annular space 34, the horn-shaped outer ports of the third production connecting holes 35 are positioned in the three-level coal seam experimental cabin 47, and the horn-shaped outer ports of the third production connecting holes 35 are connected with vent holes arranged on three-level coal seam coal samples in the three-level coal seam experimental cabin 47.

In one embodiment of the invention, the multi-channel wellbore 11 is manufactured using additive manufacturing. Specifically, the multi-channel wellbore 11 is a unitary multi-channel structure based on additive manufacturing technology, i.e. rapid prototyping by 3D printing technology. The multi-channel type shaft 11 structural design based on the additive manufacturing technology is superior to the traditional fastening piece connecting type oil pipe shaft structural design in terms of tightness, rigidity and stability, and effectively prevents the pressure balance in each independent closed annular space from being damaged, and experimental results are affected.

In order to improve sealing performance, the bottoms of the rectangular peripheral edges of the primary coal seam partition plate 65, the secondary coal seam partition plate 69 and the top sealing cover plate 48 are provided with composite sealing strips 46 which are in sliding fit with the inner wall of the oil-gas reservoir experiment cabin body 13, the lower edge of the inner diameter of the round hole is provided with O-shaped composite sealing pieces 62 which are in sliding fit with the multi-channel pit shaft 11, effective sealing among all levels of coal seam experiment cabins is achieved, and pressure balance in each independent closed cabin is prevented from being damaged, and experimental results are influenced. Preferably, the inner diameter of the O-ring composite seal 62 is the same size as the outer diameter of the multi-channel wellbore 11 to further enhance sealing performance.

As shown in fig. 1, the multi-stage coalbed methane combined mining experimental device comprises a junction box 5, a bottom cabinet 28, an experiment table 29 and an exhaust fan 27, wherein an oil supply barrel 22, an air supply tank 26 and an auxiliary material control box 24, and a primary air collecting bottle 18, a secondary air collecting bottle 19, a tertiary air collecting bottle 20 and the exhaust fan 27 are arranged in the bottom cabinet 28; the experiment table 29 is arranged above the bottom cabinet 28; the main controller 17, the oil gas pipe control box 15, the experiment cabin confining pressure device 200, the multi-channel shaft 11, the junction box 5, the electric cabinet 3, the pipeline control box 4, the hydraulic cylinder support 6, the hydraulic cylinder 8, the hydraulic cylinder connecting piece 9, the air pump 1, the oil pump 2, the signal lamp 14 and the matrix keyboard 16 are arranged on the experiment table 29, and each component and pipeline space in the multi-stage coalbed methane combined production experiment device are reasonable in layout and convenient to operate and overhaul.

The multi-stage coalbed methane combined mining experimental device comprises a signal lamp 14, a matrix keyboard 16 and a main controller 17, and experimental key index elements such as experimental running states, gas liquid flow and the like can be displayed on a display screen of the main controller 17 in real time under the control action of the main controller 17. If the experiment is interrupted, the buzzer alarms and prompts, and meanwhile, the signal lamp 14 flashes, so that the operation safety of the experiment is improved.

The foregoing is merely a few embodiments of the present invention and those skilled in the art may make various modifications or alterations to the embodiments of the present invention in light of the disclosure herein without departing from the spirit and scope of the invention.

Claims

1. Multistage coalbed methane closes adopts experimental apparatus, its characterized in that includes:

a production string disposed within the production wellbore at a center;

2. The multi-stage coalbed methane co-production experimental device of claim 1, wherein the tail pipe power mechanism comprises a screw mechanism.

3. The multi-stage coalbed methane co-production experimental device of claim 2, wherein the tail pipe power mechanism comprises a one-way circulation device connected to an upper end of the screw mechanism, the screw mechanism being in communication with the central production well bore through the one-way circulation device, the one-way circulation device allowing oil to flow from the screw mechanism to the central production well bore and preventing oil from flowing from the central production well bore to the screw mechanism.

4. The multi-stage coalbed methane co-production experimental device of claim 1, wherein the hydrocarbon reservoir experimental capsule has a first sidewall and a second sidewall perpendicular to an X-axis, and a third sidewall and a fourth sidewall perpendicular to a Y-axis; the multi-stage coalbed methane combined production experimental device comprises an experimental cabin confining pressure device, wherein the experimental cabin confining pressure device comprises an X-direction confining pressure mechanism and a Y-direction confining pressure mechanism;

the X-direction confining pressure mechanism comprises an X fixed block, an X moving block and an X-direction driving mechanism, wherein the X fixed block is in butt joint with the first side wall, the X moving block is in butt joint with the second side wall, and the X-direction driving mechanism is connected with the X moving block and is used for driving the X moving block to move towards the X fixed block;

the Y-direction confining pressure mechanism comprises a Y fixed block, a Y movable block and a Y-direction driving mechanism, wherein the Y fixed block is in butt joint with the third side wall, the Y movable block is in butt joint with the fourth side wall, and the Y-direction driving mechanism is connected with the Y movable block and is used for driving the Y movable block to move towards the Y fixed block.

5. The multi-stage coalbed methane combined production experimental device according to claim 1, wherein sealing cover plates are respectively arranged at the top of each layer of coalbed methane experimental cabin, the sealing cover plates can move up and down in the oil-gas reservoir experimental cabin, and the multi-channel shaft is inserted into each sealing cover plate and fixedly connected with each sealing cover plate;

the multi-stage coalbed methane combined production experimental device comprises a lower pressurizing device, wherein the lower pressurizing device is connected with the multi-channel type shaft and can drive the multi-channel type shaft to move up and down.

6. The multi-stage coalbed methane combined production experimental device according to claim 5, wherein the lower pressurizing device comprises a piston cavity, a sealing ring piston and an oil supply mechanism, the shaft tail tube is fixedly connected with the multi-channel shaft, the shaft tail tube is installed in the piston cavity through the sealing ring piston, and the oil supply mechanism can convey oil to a space above the sealing ring piston in the piston cavity.

7. The multi-stage coalbed methane combined production experimental device according to claim 5, wherein the multi-stage coalbed methane combined production experimental device comprises a hydraulic cylinder fixedly arranged above the oil-gas reservoir experimental cabin body, and a piston rod of the hydraulic cylinder is abutted with the sealing cover plate of the top layer.

8. The multi-stage coalbed methane co-production experimental device of claim 1, wherein the multi-stage coalbed methane co-production experimental device comprises an oil supply barrel capable of supplying oil to the wellbore tail pipe;

the top of each production pit shaft is equipped with the production export, and each the production export is connected with oil gas pipe control box through the oil pipe pipeline respectively, oil gas pipe control box can carry out the gas-liquid separation, the fluid after the oil gas pipe control box separation can be carried to the oil feed bucket.

9. The multi-stage coalbed methane co-production experimental device of claim 1, wherein the production wellbore is connected with the coalbed methane experimental cabin through a production connection hole, the production connection hole comprises a flared portion, and the flared portion gradually expands from the production wellbore toward the coalbed methane experimental cabin.

10. The multi-stage coalbed methane co-production experimental device of claim 1, wherein the multi-channel wellbore is manufactured with additive materials.

11. The multi-stage coalbed methane co-production experimental device of claim 1, wherein the hydrocarbon reservoir experimental capsule body comprises 3 of the coalbed experimental capsules and the multi-channel well bore comprises 3 of the production well bores.