Coal seam gas extraction drilling anti-sloughing supporting device and method

Abstract

The invention provides a coal seam gas extraction drilling anti-sloughing supporting device and a supporting method, the coal seam gas extraction drilling anti-sloughing supporting device comprises a supporting screen pipe, the supporting screen pipe comprises a plurality of screen pipe fixing plates, and every two adjacent screen pipe fixing plates are connected through a screen pipe moving part; the damping assembly is connected with the screen pipe fixing plate in a sliding mode, and the damping assembly is used for conducting anti-sloughing supporting on the coal seam gas extraction drill hole; the center pipe is connected with the multiple damping assemblies through the multiple telescopic control assemblies. The positions of the screen pipe fixing plate and other structures can be adjusted through the telescopic control assembly, so that the supporting screen pipe can stretch out and draw back, the supporting screen pipe can be conveniently placed into a coal seam gas extraction drill hole, the supporting screen pipe can be unfolded, and in the unfolding process of the supporting screen pipe, the supporting screen pipe is not prone to falling off. The damping assembly firstly makes contact with the wall of the coal seam drill hole and generates secondary stress disturbance on the coal seam, gas extraction is facilitated, when the supporting screen pipe is completely unfolded, the damping assembly is inserted into the coal seam, damage of the coal seam to the screen pipe and other structures can be reduced, and the supporting effect on the coal seam gas extraction drill hole is achieved.

Description

Technical Field

[0001] The invention relates to the field of coal seam gas extraction, and in particular to a coal seam gas extraction drilling anti-collapse support device and a support method. Background Art

[0002] Coal seam gas is a mixture of methane, carbon dioxide and nitrogen that escapes from coal and surrounding rocks. Gas is a colorless, tasteless, odorless gas that can burn or explode. It is insoluble in water and has a higher diffusion rate than air. It is non-toxic, but it can cause suffocation when the concentration is very high. There are two main forms of gas in coal seams. The gas in the permeable space is mainly in a free gas state, called free gas or free gas. This state of gas obeys the ideal gas state equation. The other is called adsorbed gas, which is mainly adsorbed on the microporous surface of coal and inside coal particles, occupying the vacancies in the coal molecular structure or the space between coal molecules. When mining coal seams, the coal body is damaged or affected by mining, and part of the gas stored in the coal body will leave the coal body and flow into the mining space.

[0003] Since the coal body in high-gas soft coal seams is relatively soft, long-distance directional drilling is often prone to hole collapse after drilling, causing borehole blockage or even scrapping, which seriously restricts the efficient extraction of underground gas and affects mine safety production. In order to prevent and control the phenomenon of borehole collapse in different coal seams, different working faces, and different stress environments, the innovation and upgrading of hole collapse prevention and control technology and methods is extremely important. In the authorized Chinese utility model patent "Announcement No.: CN214660327U, Name: Coal Seam Gas Extraction Drilling Support Device", it is through the support body A check assembly is provided on the support, and when the support leg pops out and is supported in the borehole, the check assembly is in an open state and is placed between the support leg and the bracket body. When the support leg rotates toward the receiving slot, it is restricted by the check assembly and stuck outside the receiving slot, effectively preventing the support leg supported in the borehole from shrinking and returning to the receiving slot, ensuring effective support of the support leg in the borehole, preventing the borehole from collapsing, and ensuring the smooth progress of gas extraction. However, in the above application, the support leg is difficult to open in the borehole, and the supporting performance is poor, the structural strength is low, the coal seam exerts a large force on the support device, and the support device is easily damaged. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of difficult installation and poor support performance in the prior art, and to provide a coal seam gas extraction drilling anti-collapse support device and a support method.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The present invention provides a coal seam gas extraction drilling anti-collapse support device and a support method, comprising a support screen pipe, wherein the support comprises a plurality of screen pipe fixing plates, and two adjacent screen pipe fixing plates are respectively connected through a screen pipe movable part;

[0007] Damping assembly, a plurality of damping assemblies are arranged inside the screen fixing plate, the damping assembly is slidably connected to the screen fixing plate, and the damping assembly is used for anti-collapse support of coal seam gas extraction drilling holes;

[0008] A central pipe, the central pipe being arranged inside the screen pipe fixing plate;

[0009] Telescopic control components, the central tube is connected to multiple damping components respectively through multiple telescopic control components.

[0010] In the present technical solution, the telescopic control assembly can be used to adjust the position of structures such as the screen fixing plate, so that the support screen can be telescoped, thereby facilitating the placement of the support screen into the coal seam gas extraction borehole. The support screen can be unfolded using the telescopic control assembly, and the damping assembly first contacts the coal seam borehole wall and generates secondary stress disturbance to the coal seam, which is beneficial to gas extraction. When the support screen is fully unfolded, the damping assembly has been inserted into the coal seam, which can reduce the damage of the coal seam to structures such as the screen, thereby supporting the coal seam gas extraction borehole.

[0011] Preferably, the screen tube movable part comprises an extension plate and an anti-slip plate, both sides of the extension plate are connected with anti-slip plates, and the two anti-slip plates are respectively slidably connected to the two screen tube fixed plates.

[0012] In the technical solution, two screen tube fixing plates can be movably connected by using a screen tube movable part.

[0013] Preferably, movable cavities are provided on both sides of the screen tube fixing plate, and the anti-slip plates are arranged in the movable cavities.

[0014] In the technical solution, the anti-slip plate can be used to prevent the expansion plate from slipping out of the screen tube fixing plate.

[0015] Preferably, the extension plate is provided with a plurality of communication openings.

[0016] In this technical solution, coal seam gas and the like enter the support screen pipe through the connecting port.

[0017] Preferably, the damping assembly comprises an anti-outlet plate and a damping block, and a plurality of damping blocks are connected to one side of the anti-outlet plate;

[0018] The screen tube fixing plate is provided with a telescopic opening, and one end of the damping block extends to the outside of the screen tube fixing plate through the telescopic opening.

[0019] In the technical solution, the damping assembly is used to increase the contact area between the supporting screen and the coal seam, and the protective screen can be supported in the borehole.

[0020] Preferably, the damping block is wrapped around the outside of the supporting frame, and one side of the supporting frame is connected to one side of the anti-falling plate;

[0021] The telescopic opening is connected with a positioning column, and the surface of the positioning column is slidably connected with the supporting frame.

[0022] In the technical solution, the positioning column is used to enable the damping block to move at the screen tube fixing plate, and the screen tube fixing plate can also be driven to move.

[0023] Preferably, the telescopic control assembly comprises a threaded shaft, the threaded shaft is arranged inside the central tube, and a plurality of movable plates are threadedly connected to the surface of the threaded shaft;

[0024] A plurality of control columns distributed in a circular array are arranged on the side of the movable plate, and both ends of the control columns are rotatably connected to a rotating frame respectively;

[0025] The rotating frame on one side is connected to the side of the moving plate, and the rotating frame on the other side is connected to one side of the anti-outlet plate.

[0026] In the technical solution, the telescopic control component can be used to drive the damping component and the screen tube fixing plate and other structures to move, so that the screen tube fixing plate and the damping component can be extended and contracted.

[0027] Preferably, the inner wall of the central tube is connected with a plurality of support plates, and the surface of the threaded shaft is rotatably connected to the support plates.

[0028] In this technical solution, the threaded shaft can be supported by a support plate.

[0029] Preferably, two adjacent screen tube fixing plates are connected via a disassembly mechanism, the disassembly mechanism comprises a plurality of disassembly components and a follower component, two adjacent disassembly components are connected via the follower component, and two sides of the disassembly component are detachably connected to the two screen tube fixing plates respectively;

[0030] The disassembly assembly comprises a fixing frame, the cross section of which is an H-shaped structure, and the fixing frame and the outer side of the damping assembly are detachably connected by a plurality of disassembly bolts;

[0031] The follower assembly includes a telescopic support, the two ends of which are slidably connected to the sides of two fixing frames, and elastic shielding belts are respectively provided on both sides of the fixing frames, and the two ends of the elastic shielding belts are respectively connected to the sides of the fixing frames;

[0032] The follower assembly also includes a special-shaped column, one end of the central tube is connected to the special-shaped column, and the other end of the central tube is provided with a special-shaped groove.

[0033] In the technical solution, the installation and disassembly of adjacent support screens can be completed by using the disassembly and assembly mechanism, which is convenient for changing the length of the support device and facilitating the use, transportation and storage of the support device.

[0034] The support method comprises the following steps:

[0035] Step 1: Length control. According to the length of the coal seam gas extraction borehole, multiple screen fixing plates are connected in sequence to form a support screen of corresponding length. When connecting, two support screens are placed in the fixing frame. At this time, the angle of the central pipe and the fixing frame is adjusted so that the special-shaped column at one central pipe is installed in the special-shaped groove at the other central pipe. Then, multiple disassembly and assembly bolts are installed in sequence to complete the connection of the two support screens. Then, multiple support screens are connected in sequence to form a support screen of corresponding length.

[0036] Step 2: Place the support screen pipe and lower it into the coal seam gas extraction borehole;

[0037] Step three, anti-collapse support, pull the threaded shaft to drive the moving plate to move, cooperate with the rotating frame to move the control column to the outside of the screen fixing plate, then drive the anti-out plate to move to the outside of the screen fixing plate, and then drive the supporting frame and the damping block to move to the outside of the screen fixing plate, extend the damping block out of the screen fixing plate, and then continue to drive the screen fixing plate to move outward, thereby stretching multiple screen fixing plates. When the screen fixing plate moves, multiple damping components move outward respectively, and the extension plate can be exposed at this time. Finally, the damping block is inserted into the coal body, and the screen fixing plate is in close contact with the coal seam gas extraction borehole wall.

[0038] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0039] The positive and progressive effects of the present invention are:

[0040] The present invention utilizes a telescopic control component to adjust the position of structures such as a screen fixing plate, so that the support screen can be telescoped, thereby facilitating the placement of the support screen into a coal seam gas extraction borehole. The support screen can be deployed using the telescopic control component. During the deployment of the support screen, the damping component first contacts the coal seam borehole wall and generates secondary stress disturbance to the coal seam, which is beneficial to gas extraction. When the support screen is fully deployed, the damping component has been inserted into the coal seam, which can reduce the damage of the coal seam to structures such as the screen, thereby supporting the coal seam gas extraction borehole. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1It is a structural schematic diagram of a coal seam gas extraction drilling anti-collapse support device and a support method according to an embodiment of the present invention.

[0042] Figure 2 for Figure 1 The side view structural schematic diagram of the overall contraction state of the coal seam gas extraction drilling anti-collapse support device and support method is shown.

[0043] Figure 3 for Figure 1 The side view structural schematic diagram of the overall deployed state of the coal seam gas extraction drilling anti-collapse support device and support method is shown.

[0044] Figure 4 for Figure 1 The overall internal structure schematic diagram of the coal seam gas extraction drilling anti-collapse support device and support method is shown.

[0045] Figure 5 for Figure 1 The cross-sectional structural schematic diagram of the storage state of the telescopic control component of the coal seam gas extraction drilling anti-collapse support device and support method is shown.

[0046] Figure 6 for Figure 1 The cross-sectional structural schematic diagram of the damping component of the coal seam gas extraction drilling anti-collapse support device and support method is shown.

[0047] Figure 7 for Figure 1 The diagram shown is a cross-sectional structural diagram of the disassembly and assembly components and follower components of the coal seam gas extraction drilling anti-collapse support device and support method.

[0048] Figure 8 for Figure 4 The schematic diagram of the partially enlarged structure at point A of the coal seam gas extraction drilling anti-collapse support device and support method is shown.

[0049] Description of Reference Numerals

[0050] 1. Screen tube fixing plate;

[0051] 2. Screen tube movable parts; 21. Extension plate; 22. Anti-slip plate;

[0052] 3. Damping assembly; 31. Anti-exit plate; 32. Damping block; 33. Support frame; 34. Positioning column;

[0053] 4. Center tube;

[0054] 5. telescopic control assembly; 51. threaded shaft; 52. moving plate; 53. control column; 54. rotating frame; 55. supporting plate;

[0055] 6. Disassembly and assembly of components; 61. Fixing bracket; 62. Disassembly and assembly of bolts;

[0056] 7. Follow-up assembly; 71. Telescopic support column; 72. Elastic shielding belt; 73. Special-shaped column; 74. Special-shaped groove. DETAILED DESCRIPTION

[0057] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0058] Figures 1 to 8 The structure diagram of an embodiment of the coal seam gas extraction drilling anti-collapse support device and support method of the present invention is shown. The coal seam gas extraction drilling anti-collapse support device and support method include a support screen, the support includes a plurality of screen fixing plates 1, and two adjacent screen fixing plates 1 are respectively connected by a screen movable part 2;

[0059] Damping components 3, a plurality of damping components 3 are arranged inside the screen fixing plate 1, the damping components 3 are slidably connected to the screen fixing plate 1, and the damping components 3 are used to perform anti-collapse support on the coal seam gas extraction drilling hole;

[0060] A central pipe 4, wherein the central pipe 4 is arranged inside the screen tube fixing plate 1;

[0061] The central tube 4 is connected to the plurality of damping assemblies 3 through the plurality of telescopic control assemblies 5 .

[0062] In the present technical solution, the telescopic control component 5 can be used to adjust the position of the screen fixing plate 1 and other structures, so that the support screen can be telescoped, thereby facilitating the placement of the support screen into the coal seam gas extraction borehole. The support screen can be unfolded by the telescopic control component 5. At this time, the damping component 3 is used to contact the coal seam borehole wall, and the damping component 3 is used to perform secondary disturbance on the coal seam pressure, which is beneficial to gas extraction and can reduce the damage of the coal seam to the screen fixing plate 1 and other structures, thereby supporting the coal seam gas extraction borehole.

[0063] The screen tube movable part 2 comprises an extension plate 21 and an anti-slip plate 22 . Both sides of the extension plate 21 are connected with the anti-slip plates 22 . The two anti-slip plates 22 are slidably connected with the two screen tube fixed plates 1 , respectively.

[0064] In the technical solution, the two screen tube fixing plates 1 can be movably connected by using the screen tube movable member 2 .

[0065] Both sides of the screen tube fixing plate 1 are provided with movable cavities, and the anti-slip plates 22 are arranged in the movable cavities.

[0066] In the present technical solution, the anti-slip plate 22 can prevent the extension plate 21 from slipping out of the screen tube fixing plate 1 .

[0067] The extension plate 21 is provided with a plurality of communication openings.

[0068] In this technical solution, coal seam gas and the like enter the support screen pipe through the connecting port.

[0069] When in use, the screen pipe fixing plate 1 moves under the control of the damping assembly 3 and the telescopic control assembly 5, so that the screen pipe fixing plate 1 can store and spit out the extension plate 21, thereby completing the contraction and extension of the supporting screen pipe.

[0070] The damping assembly 3 includes an anti-outlet plate 31 and a damping block 32, and a plurality of damping blocks 32 are connected to one side of the anti-outlet plate 31;

[0071] The screen tube fixing plate 1 is provided with a telescopic opening, and one end of the damping block 32 extends to the outside of the screen tube fixing plate 1 through the telescopic opening.

[0072] In the present technical solution, the damping assembly 3 can be used to increase the contact area between the supporting screen and the coal seam, and can support the protective screen in the borehole.

[0073] During use, when the coal seam in the borehole exerts a force on the supporting screen pipe, the damping block 32 can reduce the damage to the screen pipe and play a supporting role, and the two damping blocks 32 in opposite directions can support each other.

[0074] The damping block 32 can increase the contact area between the support screen and the coal seam, thereby increasing the gas extraction efficiency.

[0075] The damping block 32 is wrapped around the outside of the support frame 33, and one side of the support frame 33 is connected to one side of the anti-outlet plate 31;

[0076] The telescopic opening is connected with a positioning column 34 , and the surface of the positioning column 34 is slidably connected with the support frame 33 .

[0077] In the present technical solution, the positioning column 34 is used to enable the damping block 32 to move at the screen tube fixing plate 1 , and can also drive the screen tube fixing plate 1 to move.

[0078] When in use, after the support screen is sent into the coal seam gas extraction borehole, the telescopic control assembly 5 controls the anti-out plate 31 to move, thereby driving the damping block 32 and the support frame 33 to move to the outside of the screen fixing plate 1. After the damping block 32 is exposed from the screen fixing plate 1, the anti-out plate 31 continues to push the screen fixing plate 1 and the positioning column 34 to move in the same direction, thereby completing the extension of the support screen;

[0079] When shrinking, the opposite method can be used, and the shrunken support screen can be easily sent into the coal seam gas extraction borehole.

[0080] The telescopic control assembly 5 includes a threaded shaft 51, which is arranged inside the central tube 4, and a plurality of movable plates 52 are threadedly connected to the surface of the threaded shaft 51;

[0081] A plurality of control columns 53 distributed in a circular array are arranged on the side of the moving plate 52, and both ends of the control columns 53 are rotatably connected to a rotating frame 54;

[0082] The rotating frame 54 on one side is connected to the side of the moving plate 52 , and the rotating frame 54 on the other side is connected to one side of the anti-outgoing plate 31 .

[0083] In the present technical solution, the telescopic control component 5 can be used to drive the damping component 3 and the screen tube fixing plate 1 and other structures to move, so that the screen tube fixing plate 1 and the damping component 3 can be extended and contracted.

[0084] The inner wall of the central tube 4 is connected with a plurality of support plates 55 , and the surface of the threaded shaft 51 is rotatably connected with the support plates 55 .

[0085] In this technical solution, the threaded shaft 51 can be supported by the support plate 55 .

[0086] When in use, the threaded shaft 51 is pulled to drive the movable plate 52 to move. At this time, the control column 53 can be driven to move outward with the cooperation of the rotating frame 54, thereby driving the anti-outlet plate 31 to move, and further controlling the extension and contraction of the screen tube fixing plate 1.

[0087] Two adjacent screen tube fixing plates 1 are connected by a disassembly mechanism, and the disassembly mechanism includes a plurality of disassembly components 6 and a follower component 7. Two adjacent disassembly components 6 are connected by the follower component 7, and the two sides of the disassembly component 6 are detachably connected to the two screen tube fixing plates 1 respectively;

[0088] The disassembly assembly 6 comprises a fixing frame 61, the cross section of the fixing frame 61 is an H-shaped structure, and the fixing frame 61 and the outer side of the damping assembly 3 are detachably connected by a plurality of disassembly bolts 62;

[0089] The follower assembly 7 includes a telescopic support 71, both ends of which are slidably connected to the sides of the two fixing frames 61, and both ends of the elastic shielding belt 72 are respectively provided on both sides of the fixing frames 61, and both ends of the elastic shielding belt 72 are respectively connected to the sides of the fixing frames 61;

[0090] The follower assembly 7 further includes a special-shaped column 73 , one end of the central tube 4 is connected to the special-shaped column 73 , and the other end of the central tube 4 is provided with a special-shaped groove 74 .

[0091] In the technical solution, the installation and disassembly of adjacent support screens can be completed by using the disassembly and assembly mechanism, which is convenient for changing the length of the support device and facilitating the use, transportation and storage of the support device.

[0092] When in use, according to the length of the coal seam gas extraction borehole, the screen pipe fixing plates 1 on both sides are placed on both sides of the fixing frame 61 respectively. At this time, the special-shaped column 73 at one central pipe 4 is installed in the special-shaped groove 74 at another central pipe 4, and then a plurality of disassembly and assembly bolts 62 are installed in sequence to connect the screen pipe fixing plate 1 and the fixing frame 61 to complete the connection between the two supporting screen pipes, and then a plurality of supporting screen pipes can be connected in sequence in the same way, thereby changing the length of the supporting device.

[0093] The support method comprises the following steps:

[0094] Step 1, length control, according to the length of the coal seam gas extraction borehole, multiple screen fixing plates 1 are connected in sequence to form a support screen of corresponding length. When connecting, two support screens are placed in the fixing frame 61. At this time, the angle of the central pipe 4 and the fixing frame 61 is adjusted so that the special-shaped column 73 at one central pipe 4 is installed in the special-shaped groove 74 at the other central pipe 4, and then multiple disassembly bolts 62 are installed in sequence to complete the connection of the two support screens, and then multiple support screens are connected in sequence to form a support screen of corresponding length;

[0095] Step 2: Place the support screen pipe and lower it into the coal seam gas extraction borehole;

[0096] Step 3, anti-collapse support, pull the threaded shaft 51, thereby driving the moving plate 52 to move, and cooperate with the rotating frame 54 to move the control column 53 to the outside of the screen fixing plate 1, at this time, the anti-outlet plate 31 can be driven to move to the outside of the screen fixing plate 1, and then drive the support frame 33 and the damping block 32 to move to the outside of the screen fixing plate 1, extend the damping block (32) out of the screen fixing plate 1, and then continue to drive the screen fixing plate 1 to move outward, so that multiple screen fixing plates 1 are stretched out. When the screen fixing plate 1 moves, multiple damping assemblies 3 are moved outward respectively, and the extension plate 21 can be exposed at this time. Finally, the damping block 32 is inserted into the coal body, and the screen fixing plate 1 is in close contact with the coal seam gas extraction borehole wall.

[0097] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. Coal seam gas extraction drilling anti-collapse support device, characterized by: It comprises a support screen pipe, wherein the support comprises a plurality of screen pipe fixing plates (1), and two adjacent screen pipe fixing plates (1) are respectively connected via a screen pipe movable member (2); Damping components (3), a plurality of damping components (3) are arranged inside the screen tube fixing plate (1), the damping components (3) are slidably connected to the screen tube fixing plate (1), and the damping components (3) are used to perform anti-collapse support on the coal seam gas extraction drilling hole; A central tube (4), wherein the central tube (4) is arranged inside the screen tube fixing plate (1); A telescopic control component (5), wherein the central tube (4) is connected to the plurality of damping components (3) respectively through the plurality of telescopic control components (5).

2. The anti-collapse support device for coal seam gas extraction drilling according to claim 1, characterized in that: The screen tube movable part (2) comprises an extension plate (21) and an anti-slip plate (22). The extension plate (21) is connected to an anti-slip plate (22) on both sides. The two anti-slip plates (22) are respectively slidably connected to the two screen tube fixed plates (1).

3. The anti-collapse support device for coal seam gas extraction drilling according to claim 2, characterized in that: Both sides of the screen tube fixing plate (1) are provided with movable cavities, and the anti-slip plates (22) are arranged in the movable cavities.

4. The anti-collapse support device for coal seam gas extraction drilling according to claim 2, characterized in that: The extension plate (21) is provided with a plurality of communication openings.

5. The anti-collapse support device for coal seam gas extraction drilling according to claim 1, characterized in that: The damping assembly (3) comprises an anti-escape plate (31) and a damping block (32), and a plurality of damping blocks (32) are connected to one side of the anti-escape plate (31); The screen tube fixing plate (1) is provided with a telescopic opening, and one end of the damping block (32) extends to the outside of the screen tube fixing plate (1) through the telescopic opening.

6. The anti-collapse support device for coal seam gas extraction drilling according to claim 5, characterized in that: The damping block (32) is wrapped around the outside of the supporting frame (33), and one side of the supporting frame (33) is connected to one side of the anti-exit plate (31); A positioning column (34) is connected to the telescopic opening, and a surface of the positioning column (34) is slidably connected to the support frame (33).

7. The anti-collapse support device for coal seam gas extraction drilling according to claim 1, characterized in that: The telescopic control assembly (5) comprises a threaded shaft (51), the threaded shaft (51) is arranged inside the central tube (4), and a plurality of movable plates (52) are threadedly connected to the surface of the threaded shaft (51); A plurality of control columns (53) distributed in a ring array are arranged on the side of the movable plate (52), and two ends of the control columns (53) are rotatably connected to a rotating frame (54); The rotating frame (54) on one side is connected to the side of the moving plate (52), and the rotating frame (54) on the other side is connected to one side of the anti-exit plate (31).

8. The anti-collapse support device for coal seam gas extraction drilling according to claim 7, characterized in that: The inner wall of the central tube (4) is connected to a plurality of support plates (55), and the surface of the threaded shaft (51) is rotatably connected to the support plates (55).

9. The anti-collapse support device for coal seam gas extraction drilling according to claim 1, characterized in that: Two adjacent screen tube fixing plates (1) are connected via a disassembly mechanism, the disassembly mechanism comprises a plurality of disassembly components (6) and follower components (7), the two adjacent disassembly components (6) are connected via the follower components (7), and the two sides of the disassembly components (6) are respectively detachably connected to the two screen tube fixing plates (1); The disassembly assembly (6) comprises a fixing frame (61), the cross section of the fixing frame (61) is an H-shaped structure, and the fixing frame (61) and the outer side of the damping assembly (3) are detachably connected via a plurality of disassembly bolts (62); The follower assembly (7) comprises a telescopic support (71), the two ends of the telescopic support (71) are respectively slidably connected to the side surfaces of two fixing frames (61), and elastic shielding belts (72) are respectively arranged on both sides of the fixing frames (61), and the two ends of the elastic shielding belt (72) are respectively connected to the side surfaces of the fixing frames (61); The follower assembly (7) further comprises a special-shaped column (73), one end of the central tube (4) is connected to the special-shaped column (73), and the other end of the central tube (4) is provided with a special-shaped groove (74).

10. A method for obtaining a support device for preventing the collapse of a borehole in coal seam gas extraction according to claim 1, characterized in that: The support method comprises the following steps: Step 1, length control, according to the length of the coal seam gas extraction borehole, multiple screen fixing plates (1) are connected in sequence to form a support screen of corresponding length. When connecting, two support screens are placed in a fixing frame (61), and the angle of the central pipe (4) and the fixing frame (61) is adjusted so that the special-shaped column (73) at one central pipe (4) is installed in the special-shaped groove (74) at the other central pipe (4), and then multiple disassembly bolts (62) are installed in sequence to complete the connection of the two support screens, and then multiple support screens are connected in sequence to form a support screen of corresponding length; Step 2: Place the support screen pipe and lower it into the coal seam gas extraction borehole; Step 3: Anti-collapse support: pull the threaded shaft (51) to drive the movable plate (52) to move, and cooperate with the rotating frame (54) to move the control column (53) to the outside of the screen fixing plate (1). At this time, the anti-exit plate (31) can be driven to move to the outside of the screen fixing plate (1), and then the support frame (33) and the damping block (32) can be driven to move to the outside of the screen fixing plate (1), and the damping block (32) is extended out of the screen fixing plate (1). Then, the screen fixing plate (1) is continued to be driven to move outward, so that multiple screen fixing plates (1) are stretched out. When the screen fixing plate (1) moves, multiple damping components (3) are moved outward respectively, and the extension plate (21) can be exposed at this time. Finally, the damping block (32) is inserted into the coal body, and the screen fixing plate (1) is in close contact with the wall of the coal seam gas extraction borehole.

Images