Soft low-permeability coal seam gas extraction drilling wall protecting and supporting device

Abstract

The utility model relates to the technical field of gas extraction, in particular to a soft low-permeability coal seam gas extraction drilling wall protection supporting device which comprises a supporting pipe, a threaded pipe is arranged on the inner wall of the top end of the supporting pipe, a threaded groove is formed in the inner wall of the bottom end of the supporting pipe, an anti-loosening mechanism is arranged on the threaded pipe, an annular cavity is formed in the supporting pipe, and the annular cavity is communicated with the threaded groove. A connector is formed in one side of the threaded pipe and communicates with the annular cavity, a through groove is formed between the annular cavity and the threaded groove, a sealing ring is arranged on the threaded groove, and an inflation mechanism is arranged between the annular cavity and the supporting pipe; according to the structure, the whole supporting structure can be inflated only through one connector of the threaded pipe on the uppermost supporting pipe, the inflation bag is expanded and protrudes outwards in the inflation groove to be tightly attached to the wall face of a drilled hole, strong lateral supporting force is provided, and the supporting structure is particularly suitable for being used in a soft and low-permeability coal seam and can effectively prevent the wall face of the drilled hole from collapsing.

Description

Technical Field

[0001] This utility model relates to the field of gas extraction technology, specifically to a borehole wall support device for gas extraction in soft, low-permeability coal seams. Background Technology

[0002] As is well known, gas extraction in soft, low-permeability coal seams is an extremely challenging task. Soft, low-permeability coal seams are typically characterized by loose structure and low strength, making them susceptible to deformation or collapse under external pressure. This poses significant difficulties for drilling operations, as the borehole wall may lose stability due to the pressure of the surrounding coal. Low permeability means poor gas flow within the coal seam, requiring artificial means (such as fracturing and injection) to improve gas release efficiency. However, if the borehole wall cannot remain stable during this process, the effectiveness of these measures will be greatly reduced. Due to the soft and unstable nature of the coal seam, partial or even complete collapse may occur during and after drilling, potentially damaging equipment and threatening the safety of operators. Therefore, it is necessary to propose solutions to this technical problem. Utility Model Content

[0003] Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this utility model provides a support device for the borehole wall of gas drainage in soft, low-permeability coal seams.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, this utility model provides the following technical solution: a support device for the borehole wall of gas drainage in soft, low-permeability coal seams, comprising a support pipe, a threaded tube on the inner wall of the top end of the support pipe, a threaded groove on the inner wall of the bottom end of the support pipe, an anti-loosening mechanism on the threaded tube, an annular cavity inside the support pipe, an interface on one side of the threaded tube communicating with the annular cavity, a through groove between the annular cavity and the threaded groove, a sealing ring on the threaded groove, an inflation mechanism between the annular cavity and the support pipe, the inflation mechanism comprising an inflation groove and an inflation bladder, the inflation groove being located on the outside of the support pipe and communicating with the annular cavity, the inflation bladder being installed on the inflation groove, a sealing mechanism on the top of the support pipe, and multiple inflation mechanisms arranged in an array.

[0007] Furthermore, the present invention is improved in that the anti-loosening mechanism includes a locking ring groove and a fastening groove. The locking ring groove is formed on the threaded groove, and the fastening groove is formed on one side of the support tube. A connecting groove is formed at the top of the fastening groove, and a fastening hole is formed between the connecting groove and the outer side of the threaded tube. A bearing seat is provided on the fastening groove, and a lead screw is provided on the bearing seat. A sealing head is provided between the lead screw and one end of the fastening groove. A sliding block is provided between the lead screw and the connecting groove. A threaded groove is formed on the sliding block, and the lead screw passes through the threaded groove. A fastening post is provided between the sliding block and the fastening hole.

[0008] Furthermore, the present invention is improved in that the fastening column has arc edges on both sides at one end.

[0009] Furthermore, the present invention is improved in that the sealing mechanism includes a sealing ring, which is installed at the top end of the support tube and the top end of the threaded tube.

[0010] Furthermore, the present invention is improved by providing a cut-resistant sleeve on the outer side of the inflatable bladder.

[0011] Furthermore, the present invention is improved by providing an anti-slip block on the outer side of the anti-cut sleeve.

[0012] Furthermore, the present invention is improved by providing a reinforcing skeleton inside the annular cavity.

[0013] Furthermore, the present invention is improved in that the reinforcing frame is provided in multiple and arranged in an array.

[0014] (III) Beneficial Effects

[0015] Compared with the prior art, this utility model provides a support device for the borehole wall of gas drainage in soft and low-permeability coal seams, which has the following beneficial effects:

[0016] This borehole support device for gas drainage in soft, low-permeability coal seams allows multiple support pipes to be quickly and precisely spliced ​​together via threaded pipes and grooves. A sealing mechanism at the joints ensures airtightness, preventing gas leakage and maintaining the normal operating environment of the internal air bladder. Inflation equipment inflates the annular cavity inside the support pipe, causing the air bladder to expand and protrude outwards from the inflation groove, tightly fitting the borehole wall and providing strong lateral support. It is particularly suitable for use in soft, low-permeability coal seams, effectively preventing borehole wall collapse and ensuring smooth gas drainage operations. Only one joint on the threaded pipe of the uppermost support pipe is needed to inflate the entire support structure, greatly simplifying the operation process, reducing manpower and material costs, and significantly shortening preparation time and improving work efficiency in practical applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This utility model Figure 1 Schematic diagram of the central support tube structure;

[0019] Figure 3 This is a half-sectional view of the structure of this utility model in its unpacked state;

[0020] Figure 4 This utility model Figure 1 A partially enlarged frontal half-section view of the structure of a threaded pipe.

[0021] In the diagram: 1. Support tube; 2. Threaded tube; 3. Sealing ring; 4. Inflatable bladder; 5. Bearing housing; 6. Lead screw; 7. Sealing head; 8. Sliding block; 9. Fastening column; 10. Sealing ring; 11. Anti-slip block; 12. Reinforcing frame; 13. Interface; 14. Annular cavity; 15. Through groove; 16. Locking ring groove. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Please see Figure 1-4This utility model relates to a borehole wall support device for gas drainage in soft, low-permeability coal seams. It includes a support pipe 1, a threaded pipe 2 on the inner wall of the top end of the support pipe 1, and a threaded groove on the inner wall of the bottom end of the support pipe 1. An anti-loosening mechanism is provided on the threaded pipe 2. An annular cavity 14 is formed inside the support pipe 1. An interface 13 is formed on one side of the threaded pipe 2, connecting the annular cavity 14. A through groove 15 is formed between the annular cavity 14 and the threaded groove. A sealing ring 3 is provided on the threaded groove. An air-inflating mechanism is provided between the annular cavity 14 and the support pipe 1. The air-inflating mechanism includes an air-inflating groove and... An inflatable bladder 4 is provided, with an inflation groove formed on the outside of the support pipe 1 and connected to the annular cavity 14. The inflatable bladder 4 is installed on the inflation groove. A sealing mechanism is provided at the top of the support pipe 1. Multiple inflation mechanisms are provided and arranged in an array. In this embodiment, multiple support pipes 1 are rotated and spliced ​​as needed to insert into the gas drainage borehole of the soft, low-permeability coal seam. During splicing, the sealing rings 3 of multiple support pipes 1 are removed, and the threaded pipe 2 at one end of the support pipe 1 is inserted into the threaded groove of another support pipe 1, so that the interface 13 is aligned and connected with the through groove 15 of another support pipe 1. The sealing mechanism enables the two support pipes to communicate. 1. Seal the joint. Repeat the above steps to splice multiple support tubes 1 together. The sealing ring 3 of the bottom support tube 1 does not need to be removed, thus ensuring the sealing of the annular cavity 14 in the bottom support tube 1. Then, use an anti-loosening mechanism to lock the multiple support tubes 1 together to prevent the threads from loosening. Then, connect the interface 13 on the threaded tube 2 side of the top support tube 1 to the pipe of the inflation device and insert it. Use the inflation device to deliver gas through the interface 13 to the annular cavity 14, and then through the through groove 15 to the interface 13 on the next threaded tube 2 side into the annular cavity 1 of the next support tube 1. In step 4, the annular cavity 14 in multiple support pipes 1 is inflated, allowing the air bladder 4 in the inflation mechanism to expand outward in the inflation groove. The inflated air bladder 4 compresses the outer wall of the gas extraction borehole in the soft, low-permeability coal seam, thus making the support pipe 1 more firmly fixed in the borehole. This allows for quick and convenient assembly of multiple support pipes 1 together. Moreover, by inserting only one interface 13, the air bladder 4 of each support pipe 1 can be inflated, ensuring a firm and reliable fixation in the gas extraction borehole of the soft, low-permeability coal seam. This facilitates personnel using the extraction pipeline for gas extraction operations.

[0024] To ensure stable locking between the two support tubes 1, the anti-loosening mechanism in this design includes a locking ring groove 16 and a fastening groove. The locking ring groove 16 is formed on the threaded groove, and the fastening groove is formed on one side of the support tube 1. A connecting groove is formed at the top of the fastening groove, and a fastening hole is formed between the connecting groove and the outer side of the threaded tube 2. A bearing seat 5 is provided on the fastening groove, and a lead screw 6 is provided on the bearing seat 5. A sealing head 7 is provided between the lead screw 6 and one end of the fastening groove. A sliding block 8 is provided between the lead screw 6 and the connecting groove. A threaded groove is formed on the sliding block 8, through which the lead screw 6 passes. A fastening post 9 is provided between the sliding block 8 and the fastening hole. When the two support tubes 1 are assembled together... Then, the fastening post 9 on the fastening hole of one support pipe 1 is aligned with the locking ring groove 16 on the threaded groove of the other support pipe 1. By rotating the sealing head 7 sealed on the fastening groove, the sealing head 7 drives the screw 6 to rotate by an angle. It can move linearly on the screw 6 through the sliding block 8. The installation method of the sliding block 8 and the screw 6 are common screw hole installation methods in the prior art, which will not be described in detail in this structure. The sliding block 8 drives the fastening post 9 in the fastening hole to move linearly, so that the fastening post 9 abuts in the locking ring groove 16, which can firmly fix the threaded pipe 2 in the threaded groove of the other support pipe 1, thereby preventing loosening. The sealing head 7 has a certain sealing damping performance in the fastening groove, so that it will not loosen under normal vibration and shaking.

[0025] In order to further ensure that one end of the fastening post 9 fits snugly against the locking ring groove 16, in this design, one end of the fastening post 9 is provided with arc edges on both sides. The arc plates enable the fastening post 9 to fit snugly against the locking ring groove 16 more closely, thereby improving the locking stability of the threaded tube 2 in the threaded groove.

[0026] To ensure the sealing of the connection between the two support pipes 1, in this solution, the sealing mechanism includes a sealing ring 10. The sealing ring 10 is installed at the top end of the support pipe 1 and the top end of the threaded pipe 2. By setting the sealing ring 10 at the top end of the support pipe 1 and the top end of the threaded pipe 2, the gap at the threaded connection can be effectively sealed, thereby ensuring the sealing of the through groove 15.

[0027] In order to prevent hard objects in the soil from scratching the airbag 4, in this solution, the airbag 4 is provided with a cut-proof sleeve on the outside. The cut-proof sleeve can improve the protective performance of the airbag 4 and prevent hard objects from scratching the airbag 4.

[0028] In order to improve the stability of the airbag 4 in soft and low-permeability coal seams, in this solution, the outer side of the anti-cutting sleeve is provided with an anti-slip block 11. The anti-slip block 11 on the outer side of the anti-cutting sleeve can improve the support stability of the airbag 4 in soft and low-permeability coal seams.

[0029] To improve the strength of this structure, a reinforcing frame 12 is provided inside the annular cavity 14 in this design. The reinforcing frame 12 strengthens the outer and inner walls of the support tube 1, thereby improving the structural strength of the support tube 1. Multiple reinforcing frames 12 are provided and arranged in an array, which further enhances the structural strength of the support tube 1.

[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A gas extraction borehole wall supporting device for soft and low permeability coal seams, comprising a support pipe (1), characterized in that, The inner wall of the top end of the support tube (1) is provided with a threaded tube (2), the inner wall of the bottom end of the support tube (1) is provided with a threaded groove, the threaded tube (2) is provided with an anti-loosening mechanism, the inside of the support tube (1) is provided with an annular cavity (14), the side of the threaded tube (2) is provided with an interface (13), the interface (13) is connected to the annular cavity (14), a through groove (15) is provided between the annular cavity (14) and the threaded groove, a sealing ring (3) is provided on the threaded groove, an inflation mechanism is provided between the annular cavity (14) and the support tube (1), the inflation mechanism includes an inflation groove and an inflation bag (4), the inflation groove is opened on the outside of the support tube (1) and is connected to the annular cavity (14), the inflation bag (4) is installed on the inflation groove, the top of the support tube (1) is provided with a sealing mechanism, and multiple inflation mechanisms are provided and arranged in an array.

2. The soft low-permeability coal seam gas extraction borehole sidewall supporting device according to claim 1, characterized in that, The anti-loosening mechanism includes a locking ring groove (16) and a fastening groove. The locking ring groove (16) is opened on the threaded groove. The fastening groove is opened on one side of the support tube (1). A connecting groove is opened at the top of the fastening groove. A fastening hole is opened between the connecting groove and the outer side of the threaded tube (2). A bearing seat (5) is provided on the fastening groove. A lead screw (6) is provided on the bearing seat (5). A sealing head (7) is provided between the lead screw (6) and one end of the fastening groove. A sliding block (8) is provided between the lead screw (6) and the connecting groove. A threaded groove is opened on the sliding block (8). The lead screw (6) passes through the threaded groove. A fastening post (9) is provided between the sliding block (8) and the fastening hole.

3. The borehole wall support device for gas drainage in soft, low-permeability coal seams according to claim 2, characterized in that, The fastening post (9) has arc edges on both sides at one end.

4. The borehole wall support device for gas drainage in soft, low-permeability coal seams according to claim 1, characterized in that, The sealing mechanism includes a sealing ring (10), which is installed at the top end of the support tube (1) and the top end of the threaded tube (2).

5. The borehole wall support device for gas drainage in soft, low-permeability coal seams according to claim 1, characterized in that, The airbag (4) is provided with a cut-resistant sleeve on its outer side.

6. The borehole wall support device for gas drainage in soft, low-permeability coal seams according to claim 5, characterized in that, The outer side of the cut-resistant sleeve is provided with an anti-slip block (11).

7. The borehole wall support device for gas drainage in soft, low-permeability coal seams according to claim 1, characterized in that, The annular cavity (14) is provided with a reinforcing skeleton (12).

8. The borehole wall support device for gas drainage in soft, low-permeability coal seams according to claim 7, characterized in that, The reinforced frame (12) is provided in multiple and arranged in an array.

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