Coal measures gas multilayer co-mining device

Abstract

The application discloses a coal measure gas multilayer co-mining device, and relates to the technical field of coal measure gas mining. The device comprises a pumping pipe and a sealing assembly. The pumping pipe is arranged in a pumping hole. The pumping hole is surrounded by a rock layer and a coal measure gas layer. A space in the pumping hole and flush with the coal measure gas layer is a pumping space. The pumping pipe is externally fixed with the sealing assembly. The space between two adjacent sealing assemblies is the pumping space corresponding to the coal measure gas layer. The sealing assembly comprises a sealing ring and a ring capsule. The ring capsule is fixed to the outer circumferential side of the sealing ring. A section of the pumping pipe exposed to the pumping space is provided with a valve body for controlling the pumping of the coal measure gas. The application can effectively solve the technical problem of low co-mining productivity caused by the interlayer interference phenomenon during the multilayer co-mining of the coal measure gas, and can improve the pumping efficiency of the multilayer co-mining.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal measures gas exploitation, and in particular to a coal measures gas multi-layer co-extraction device. BACKGROUND

[0002] Coal measures gas refers to all natural gas generated in the process of coal formation with methane as the main component, and can be divided into coalbed methane, shale gas and tight sandstone gas according to the lithology. In some areas with multiple coal measures gas layers, there are characteristics such as multiple layers, small layer spacing and high gas content. Therefore, multi-layer co-extraction technology is often used for targeted extraction. However, multi-layer co-extraction may cause interlayer interference, resulting in low combined production capacity.

[0003] A coal measures gas multi-layer combined extraction device, method and system are disclosed in the Chinese patent document with the publication number CN116696291A and the publication date of September 5, 2023. The device includes multiple extraction assemblies arranged at each target reservoir in the well. The extraction assemblies are arranged in the perforated section of the target reservoir. The extraction assemblies divide the oil casing annulus area into an independent extraction zone corresponding to the perforated section and a flow channel that keeps the oil casing annulus area continuously connected. The independent extraction zone has a sampling outlet that connects the oil casing annulus area and is unidirectionally conductive. Based on the technical scheme of the invention, the interference between different reservoirs of coal measures vertical wells can be avoided, and the significance of combined extraction due to interlayer interference can be avoided. The invention can provide precise control for gas well extraction and real-time accurate production data, and provide reliable technical means for fine management of coal measures gas vertical wells.

[0004] The above-mentioned technology can avoid interference between different reservoirs, but each extraction space is an independent closed space, and the coal measures gas layers cannot communicate with each other. During multi-layer combined extraction, the extraction efficiency is not high. SUMMARY

[0005] To solve the above technical problems, the present application provides a coal measures gas multi-layer co-extraction device. The present application can effectively solve the technical problem of low combined production capacity caused by interlayer interference during multi-layer co-extraction, and improve the extraction efficiency of multi-layer co-extraction.

[0006] The present application is achieved by using the following technical solutions:

[0007] The coal measure gas multilayer co-extraction device comprises an extraction pipe and a sealing assembly, the extraction pipe is arranged in an extraction hole, the extraction hole is surrounded by a rock layer and a coal measure gas layer, the sealing assembly is fixed to the outer wall of the extraction pipe, the sealing assembly is arranged at the intersection of the rock layer and the coal measure gas layer, the space between two adjacent sealing assemblies corresponding to the coal measure gas layer is the extraction space, the sealing assembly comprises a sealing ring and a ring capsule, the ring capsule is fixed to the outer circumferential side of the sealing ring, and a valve body for controlling the extraction of the coal measure gas is arranged on the section of the extraction pipe exposed to the extraction space. During extraction, the space between the two sealing assemblies is formed into the extraction space by the expansion of the corresponding ring capsule, the extraction space is simultaneously formed in two adjacent coal measure gas layers, so that the two coal measure gas layers are synchronously extracted, and the other ring capsules are in a state of being compressed. During the extraction of the extraction pipe, the coal measure gas layers are processed in sequence from top to bottom.

[0008] A gas equalizing assembly is arranged between the two sealing assemblies corresponding to each extraction space, the gas equalizing assembly comprises a flow guide sleeve, an air inlet, an air outlet and a connecting pipe, the flow guide sleeve is fixed between the two adjacent sealing assemblies, a plurality of air inlets are formed in the outer surface of the flow guide sleeve, the air inlets are connected to the air outlet through the connecting pipe, and the air outlet is located on the inner surface of the flow guide sleeve. The gas equalizing assembly can adjust the pressure of the coal measure gas flow entering the extraction pipe from the coal measure gas layer, and when the two adjacent coal measure gas layers are synchronously extracted, the pressure of the coal measure gas flow of the coal measure gas layer located at the lower side is slightly greater than that of the coal measure gas layer located at the upper side.

[0009] The outer diameter of the flow guide sleeve is smaller than the diameter of the extraction hole, and the inner diameter is greater than the diameter of the extraction pipe.

[0010] A plurality of flow resistance assemblies are arranged on the connecting pipe; the flow resistance assembly comprises a driving rod, a mounting seat, a return spring and a flow resistance plate, the mounting seat is fixed to the outer wall of the connecting pipe, the mounting seat and the position of the connecting pipe corresponding to the mounting seat are provided with through holes, the driving rod extends into the connecting pipe, one end of the driving rod is provided with a limiting end, the return spring is arranged between the limiting end and the mounting seat, the driving rod is a through pipe structure, the driving rod is connected to the flow resistance plate on one side in the connecting pipe, and when the flow resistance plate is filled with liquid, the flow resistance plate is in an arc state.

[0011] The driving rod is connected to an external hydraulic control pipe.

[0012] Magnets are arranged on the driving rod in an axial array.

[0013] An electromagnet is fixed to the mounting seat and corresponds to the magnets.

[0014] The auxiliary pipe is provided with air holes, and sealing rings are arranged on the upper and lower sides of the air holes, so that the auxiliary pipe and the extraction pipe form a separate annulus at the air holes.

[0015] The top of the extraction hole is provided with a sealing head, and the sealing head is provided with a through hole for the extraction pipe to pass through.

[0016] The air inlet is embedded with a blocking net.

[0017] Compared with the prior art, the beneficial effects of the present application are as follows:

[0018] 1、The present application uses the expansion of the corresponding annulus to simultaneously construct extraction space for two adjacent coal measure gas layers for synchronous extraction, and other annuli are in a state of contraction, which can improve the extraction efficiency and facilitate the communication between other coal measure gas layers, so that the coal measure gas in the high-permeability coal measure gas layer enters the low-permeability coal measure gas layer for crack-assisted reconstruction, thereby improving the subsequent extraction efficiency.

[0019] 2、The present application is provided with a gas equalizing assembly between the two sealing rings corresponding to each coal measure gas layer, which can adjust the coal measure gas flow pressure entering the extraction pipe from the coal measure gas layer, and when two adjacent coal measure gas layers are synchronously extracted, the coal measure gas flow pressure of the coal measure gas layer located below is slightly greater than that of the coal measure gas layer located above, thereby minimizing the disturbance between the two coal measure gas layers.

[0020] 3、The present application adjusts the damping between the magnetic force adjusting mounting seat and the driving rod to position the driving rod, which improves the precision of flow resistance and further reduces the disturbance between the two coal measure gas layers.

[0021] 4、The present application is also provided with an auxiliary pipe for injecting carbon dioxide into each layer of coal measure gas layer to displace the coal measure gas adsorbed in the rock, thereby further improving the extraction efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0022] The present application will be further described in detail below in conjunction with the drawings and specific embodiments, in which:

[0023] Figure 1 It is a structural schematic view of a coal measure gas multi-layer co-extraction device;

[0024] Figure 2 It is a structural schematic view of a gas equalizing assembly in a coal measure gas multi-layer co-extraction device;

[0025] Figure 3 It is a structural schematic view of a flow resistance assembly in a coal measure gas multi-layer co-extraction device;

[0026] Figure 4It is a kind of coal gas multilayer co-mining device auxiliary pipe structure schematic diagram;

[0027] Marked in the figure:

[0028] 1, extraction hole, 2, coal gas layer, 3, rock layer, 4, extraction pipe, 5, end cap, 6, sealing ring, 7, ring capsule, 8, auxiliary pipe, 9, gas distribution assembly, 10, valve body, 81, gas hole, 82, sealing ring, 91, flow guide sleeve, 92, gas inlet, 93, gas outlet, 94, communication pipe, 95, flow resistance assembly, 951, drive rod, 952, mounting seat, 953, reset spring, 954, electromagnetic seat, 955, magnet, 956, flow resistance plate. DETAILED DESCRIPTION

[0029] Example 1

[0030] As a preferred embodiment of the present application, a kind of coal gas multilayer co-mining device, including extraction pipe 4 and sealing assembly, the extraction pipe 4 is placed in extraction hole 1, and the extraction hole 1 is surrounded by rock layer 3 and coal gas layer 2, the pipe wall of the extraction pipe 4 is fixed with sealing assembly, the sealing assembly is arranged at the intersection of rock layer 3 and coal gas layer 2, corresponding to the space between two sealing assemblies adjacent to coal gas layer 2 above and below, i.e. extraction space, the sealing assembly includes sealing ring 6 and ring capsule 7, the outer circumferential side of the sealing ring 6 is fixed with ring capsule 7, and a section of the extraction pipe 4 exposed in extraction space is provided with valve body 10 for controlling extraction coal gas. When extracting, the space between two sealing assemblies is formed into extraction space by the expansion of corresponding ring capsule 7, and two adjacent coal gas layers 2 are simultaneously constructed into extraction space to be extracted synchronously, and other ring capsules 7 are in the state of contraction.

[0031] Example 2

[0032] As another preferred embodiment of the present application, this embodiment is based on example 1, and a gas distribution assembly 9 is arranged between the two sealing assemblies corresponding to each of the extraction spaces, the gas distribution assembly 9 includes flow guide sleeve 91, gas inlet 92, gas outlet 93 and communication pipe 94, the flow guide sleeve 91 is fixed between two adjacent sealing assemblies, the outer surface of the flow guide sleeve 91 is provided with a plurality of gas inlets 92, the gas inlets 92 are communicated with the gas outlets 93 through the communication pipes 94, and the gas outlets 93 are located on the inner surface of the flow guide sleeve 91. The outer diameter of the flow guide sleeve 91 is less than the diameter of the extraction hole 1, and the inner diameter is greater than the diameter of the extraction pipe 4.

[0033] The communication pipe 94 is provided with a plurality of flow resistance components 95; the flow resistance component 95 comprises a driving rod 951, a mounting base 952, a reset spring 953 and a flow resistance plate 956, wherein the mounting base 952 is fixed to one side of the communication pipe 94, the driving rod 951 is slidably connected in the mounting base 952, the driving rod 951 also sealingly slides into the communication pipe 94, the driving rod 951 is connected with the mounting base 952 by the reset spring 953 on one side, the driving rod 951 is a through pipe structure, one side of the driving rod 951 in the communication pipe 94 is communicated with the flow resistance plate 956, the flow resistance plate 956 is made of a deformable and inextensible material, when the flow resistance plate 956 is full of liquid, the flow resistance plate 956 is in an arc shape.

[0034] The gas equalizing component 9 can adjust the coalbed gas flow pressure from the coalbed gas layer 2 into the extraction pipe 4, and when two adjacent distributed coalbed gas layers 2 are synchronously extracted, the coalbed gas flow pressure of the relatively lower coalbed gas layer 2 is slightly greater than that of the upper coalbed gas layer 2, so as to reduce the disturbance between the two coalbed gas layers 2 as much as possible. It should be explained that the flow resistance plate 956 is made of a deformable and inextensible material, when the flow resistance plate 956 is full of liquid, the flow resistance plate 956 is in an arc shape, so that the loading of the flow resistance plate 956 can be realized, the driving rod 951 can be connected with an external hydraulic control pipe to control the liquid pressure in the driving rod 951, in the embodiment, the flow pressure can be controlled by loading different numbers of flow resistance plates 956, the flow resistance plate 956 can not only control the flow pressure, but also can flow resistance in a relatively soft manner.

[0035] Embodiment 3

[0036] As another preferred embodiment of the present application, on the basis of embodiment 2, the driving rod 951 is provided with a plurality of magnets 955 arranged along the axial direction thereof, the mounting base 952 is fixed with an electromagnetic base 954, a plurality of electromagnets corresponding to the magnets 955 are fixed on the electromagnetic base 954, and the electromagnets can attract the magnets 955.

[0037] The magnetic force of the electromagnet is adjustable, in the implementation, the damping between the mounting base 952 and the driving rod 951 is adjusted by controlling the magnetic force of the electromagnet, and the driving rod 951 can also be positioned.

[0038] Embodiment 4

[0039] As the best embodiment of the present application, the present application comprises the extraction pipe 4 and the sealing assembly, the extraction pipe 4 is arranged in the extraction hole 1, the extraction hole 1 is surrounded by the rock layer 3 and the coal measure gas layer 2, the sealing assembly is fixed outside the pipe wall of the extraction pipe 4, the sealing assembly is arranged at the intersection of the rock layer 3 and the coal measure gas layer 2, the space between the two sealing assemblies corresponding to the coal measure gas layer 2 and adjacent to each other is the extraction space, the sealing assembly comprises the sealing ring 6 and the ring capsule 7, the ring capsule 7 is fixed on the outer circumferential side of the sealing ring 6, and a section of the extraction pipe 4 exposed in the extraction space is provided with the valve body 10 for controlling the extraction of the coal measure gas. During the extraction, the space between the two sealing assemblies is formed into the extraction space by the expansion of the corresponding ring capsule 7, the extraction space is simultaneously constructed for the two adjacent distributed coal measure gas layers 2 so as to be synchronously extracted, and the other ring capsules 7 are in the state of being contracted. It should be explained that in the embodiment, the two coal measure gas layers 2 are extracted each time, so that the extraction efficiency is improved, and the two coal measure gas layers 2 are adjacent to each other, that is, there is no other coal measure gas layer 2 between the two coal measure gas layers 2, but there may be the rock layer 3 and the like. Since the two adjacent coal measure gas layers 2 are extracted each time, the other coal measure gas layers 2 may be communicated with each other. Thus, during the extraction, the space between the two adjacent distributed coal measure gas layers 2 is formed into the extraction space by the expansion of the corresponding ring capsule 7 so as to be synchronously extracted, and the other ring capsules 7 are in the state of being contracted, so that the other coal measure gas layers 2 are communicated with each other

[0040] A gas equalizing assembly 9 is arranged between the two sealing assemblies corresponding to each extraction space, the gas equalizing assembly 9 comprises a flow guide sleeve 91, an air inlet 92, an air outlet 93 and a communication pipe 94, the flow guide sleeve 91 is fixed between the two adjacent sealing assemblies, a plurality of air inlets 92 are formed in the outer surface of the flow guide sleeve 91, the air inlets 92 are communicated with the air outlets 93 through the communication pipe 94, and the air outlets 93 are located on the inner surface of the flow guide sleeve 91. The outer diameter of the flow guide sleeve 91 is smaller than the diameter of the extraction hole 1, and the inner diameter is larger than the diameter of the extraction pipe 4.

[0041] The communication pipe 94 is provided with a plurality of flow resistance components 95; the flow resistance component 95 comprises a driving rod 951, a mounting seat 952, a reset spring 953 and a flow resistance plate 956, the mounting seat 952 is fixed on the outer wall of the communication pipe 94, the mounting seat 952 and the mounting seat 952 correspond to the position of the communication pipe 94 and are provided with through holes, the driving rod 951 extends into the communication pipe 94, one end of the driving rod 951 is provided with a limiting end, the limiting end and the mounting seat 952 are provided with a reset spring 953, the driving rod 951 is a through pipe structure, and the driving rod 951 is connected with the flow resistance plate 956 on one side of the communication pipe 94. The driving rod 951 is connected with the external hydraulic control pipe, the flow resistance plate 956 is made of a deformable and inextensible material, and when the flow resistance plate 956 is filled with liquid, the flow resistance plate 956 is in an arc shape.

[0042] The gas equalizing component 9 can adjust the coal measure gas flow pressure from the coal measure gas layer 2 into the extraction pipe 4, and when two adjacent coal measure gas layers 2 are synchronously extracted, the coal measure gas flow pressure of the lower coal measure gas layer 2 is slightly greater than that of the upper coal measure gas layer 2. Thus, the disturbance between the two coal measure gas layers 2 is reduced as much as possible. It should be explained that the flow resistance plate 956 is made of a deformable and inextensible material, and when the flow resistance plate 956 is filled with liquid, the flow resistance plate 956 is in an arc shape, so that the loading of the flow resistance plate 956 can be realized, and the driving rod 951 can be connected with the external hydraulic control pipe to control the liquid pressure in the driving rod 951. In the embodiment, the flow pressure can be controlled by loading different numbers of flow resistance plates 956. The flow resistance plate 956 can not only control the flow pressure, but also can flow resistance in a relatively soft manner.

[0043] The driving rod 951 is provided with a plurality of magnets 955 arranged along the axial direction, the mounting seat 952 is fixed with an electromagnetic seat 954, and the electromagnetic seat 954 is fixed with an electromagnet corresponding to the magnet 955. The electromagnet can attract the magnet 955. In the embodiment, the magnetic force of the electromagnet is adjustable, and in the implementation, the damping between the mounting seat 952 and the driving rod 951 is adjusted by controlling the magnetic force of the electromagnet, and the driving rod 951 can also be positioned.

[0044] The auxiliary pipe 8 is provided with air holes 81, and sealing rings 82 are arranged on the upper and lower sides of the air holes 81, so that the auxiliary pipe 8 and the extraction pipe 4 form a separate annulus at the air holes 81. Carbon dioxide can be injected into each coal measure gas layer 2 through the auxiliary pipe 8 to displace the coal measure gas adsorbed in the rock. In the initial stage of implementation, the first coal measure gas layer 2 and the second coal measure gas layer 2 are extracted first, at this time, the annulus 7 corresponding to the first coal measure gas layer 2 and the second coal measure gas layer 2 is expanded to be blocked, and the annulus 7 corresponding to the third coal measure gas layer 2 and the fourth coal measure gas layer 2 is contracted to communicate with each other, at the same time, the valve body 10 corresponding to the first coal measure gas layer 2 and the second coal measure gas layer 2 is opened, and the valve body 10 corresponding to the third coal measure gas layer 2 and the fourth coal measure gas layer 2 is closed; at this time, the annulus 7 corresponding to the fifth coal measure gas layer 2 is expanded, and the valve body 10 corresponding to the fifth coal measure gas layer 2 is opened, the auxiliary pipe 8 is lowered into the extraction pipe 4, and the sealing ring 82 is located at the valve body 10 corresponding to the fifth coal measure gas layer 2, so that the gas provided by the auxiliary pipe 8 can enter the fifth coal measure gas layer 2 through the valve body 10 corresponding to the fifth coal measure gas layer 2 without affecting other coal measure gas layers 2.

[0045] The top of the extraction hole 1 is provided with a sealing head 5, and the sealing head 5 is provided with a through hole through which the extraction pipe 4 passes.

[0046] The air inlet 92 is embedded with a blocking net.

[0047] In this embodiment, when extracting, the expansion of the corresponding annulus 7 can simultaneously construct extraction spaces for two adjacent coal measure gas layers 2 to be extracted synchronously, and other annuli 7 are in a contracted state, which can improve the extraction efficiency and facilitate the communication between other coal measure gas layers 2, so that the coal measure gas in the coal measure gas layer 2 with high permeability enters the coal measure gas layer 2 with low permeability to assist in the reconstruction of the fissure, thereby improving the subsequent extraction efficiency. In addition, a gas equalizing assembly 9 is arranged between the two sealing rings 6 corresponding to each coal measure gas layer 2, which can adjust the coal measure gas flow pressure entering the extraction pipe 4 from the coal measure gas layer 2, and when two adjacent coal measure gas layers 2 are extracted synchronously, the coal measure gas flow pressure of the coal measure gas layer 2 located below is slightly greater than that of the coal measure gas layer 2 located above, so as to reduce the disturbance between the two coal measure gas layers 2 as much as possible. When the coal measure gas layer 2 region is extracted by the multi-layer co-extraction technology, the disturbance between the coal measure gas layers 2 can be reduced, and the extraction efficiency can be improved.

Claims

1. A multi-layer co-extraction device for coalbed methane, characterized in that: The system includes an extraction pipe (4) and a sealing assembly. The extraction pipe (4) is placed in an extraction hole (1). The extraction hole (1) is surrounded by a rock layer (3) and a coalbed methane layer (2). The space inside the extraction hole (1) that is flush with the coalbed methane layer (2) is the extraction space. A sealing assembly is fixed to the outside of the pipe wall of the extraction pipe (4). The sealing assembly is set at the junction of the rock layer (3) and the coalbed methane layer (2). The space between two adjacent sealing assemblies corresponds to the extraction space of the coalbed methane layer (2). The sealing assembly includes a sealing ring (6) and a ring bag (7). A ring bag (7) is fixed to the outer periphery of the sealing ring (6). A valve body (10) for controlling the extraction of coalbed methane is provided on the section of the extraction pipe (4) exposed in the extraction space. A gas equalization component (9) is provided between the two sealing components corresponding to each extraction space. The gas equalization component (9) includes a guide sleeve (91), an air inlet (92), an air outlet (93), and a connecting pipe (94). The guide sleeve (91) is fixed between two adjacent sealing components. Multiple air inlets (92) are opened on the outer surface of the guide sleeve (91). The air inlets (92) are connected to the air outlets (93) through the connecting pipes (94). The air outlets (93) are located on the inner surface of the guide sleeve (91). The connecting pipe (94) is provided with a plurality of flow-blocking components (95); the flow-blocking component (95) includes a drive rod (951), a mounting base (952), a return spring (953) and a flow-blocking plate (956). The mounting base (952) is fixed to the outer wall of the connecting pipe (94). The mounting base (952) and the corresponding position of the connecting pipe (94) are provided with through holes. The drive rod (951) extends into the connecting pipe (94). One end of the drive rod (951) is provided with a limiting end. A return spring (953) is provided between the limiting end and the mounting base (952). The drive rod (951) is a through pipe structure. The flow-blocking plate (956) is connected to one side of the drive rod (951) in the connecting pipe (94).

2. The coalbed methane multi-layer co-extraction device according to claim 1, characterized in that: The outer diameter of the guide sleeve (91) is smaller than the diameter of the extraction hole (1), and the inner diameter is larger than the diameter of the extraction pipe (4).

3. The coalbed methane multi-layer co-extraction device according to claim 1, characterized in that: The drive rod (951) is connected to an external hydraulic control pipe.

4. A coalbed methane multi-layer co-extraction device according to claim 3, characterized in that: The drive rod (951) is provided with magnets (955) arranged in an array along its axial direction.

5. A coalbed methane multi-layer co-extraction device according to claim 4, characterized in that: An electromagnetic base (954) is fixed on the mounting base (952), and an electromagnet corresponding to the magnet (955) is fixed on the electromagnetic base (954).

6. A coalbed methane multi-layer co-extraction device according to claim 1, characterized in that: An auxiliary pipe (8) is also provided in the extraction pipe (4). An air hole (81) is provided on the auxiliary pipe (8). Sealing rings (82) are provided on the upper and lower sides of the air hole (81), so that the auxiliary pipe (8) and the extraction pipe (4) form a separate annulus at the air hole (81).

7. A coalbed methane multi-layer co-extraction device according to claim 1, characterized in that: The top of the extraction hole (1) is provided with a sealing head (5), and the sealing head (5) is provided with a through hole for the extraction tube (4) to pass through.

8. A coalbed methane multi-layer co-extraction device according to claim 1, characterized in that: An intercepting net is embedded in the air inlet (92).

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