A drilling-type gas leakage recovery device for underground coal gasification

Abstract

This invention discloses a drilling-type gas leakage recovery device for underground coal gasification, comprising a scissor lift system. Each scissor lift consists of two rods rotatably connected at their centers. Multiple sets of scissor lifts are hinged together at their ends. A central sleeve is rotatably provided at the center of the central scissor lift, through which an external extraction pipe passes. A drill bit is fixed to the lower end of the external extraction pipe. Side sleeves are rotatably provided at the centers of the remaining scissor lifts, each containing a drill rod. Compared to existing technologies, this invention provides a sealing effect on the entire formation fracture, preventing gas leakage. The external extraction pipe, each drill rod, and each set of scissor lifts are integrated into a single unit, improving the stability of the external extraction pipe.

Description

Technical Field

[0001] This invention relates to the technical field of coal gasification mining equipment, specifically a drilling-type coal gas leakage recovery device for underground coal gasification mining. Background Technology

[0002] In underground coal gasification extraction, the presence of cracks, cavities, gaps, or low rupture pressure in the strata can cause the strata to fracture, leading to gas leakage along these gaps, resulting in economic losses and potential safety accidents. Furthermore, the presence of these gaps during gas extraction can cause external air to flow back into the strata under the negative pressure of the extraction process, affecting the purity of the gas.

[0003] Therefore, it is necessary to provide a drilling-type gas leakage recovery device for underground gasification to solve the problems mentioned in the background art. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides the following technical solution: an underground coal gasification and gas leakage recovery device using a drilling method, comprising a scissor link, wherein the scissor link is composed of two links rotatably connected together at their centers, multiple sets of the scissor links are hinged together at their ends, and a central sleeve is rotatably provided at the center of the central scissor link, wherein an external extraction pipe passes through the central sleeve, and a drill bit is fixed at the lower end of the external extraction pipe; the remaining scissor links are rotatably provided with side sleeves at their centers, and a drill rod passes through each side sleeve.

[0005] Furthermore, as a preferred embodiment, the drill rod is movably connected to the side sleeve, and the portion of the drill rod near the upper end is provided with a drill rod thread, which can be threadedly engaged with the side sleeve.

[0006] Furthermore, as a preferred embodiment, the drill rod is a hollow tube with drill marks at the bottom and extending through the top and bottom.

[0007] Furthermore, as a preferred embodiment, of the two connecting rods constituting the scissor link, one has pins at both ends, and the other has oval holes at both ends, with the pins between adjacent scissor links slidably connected to the oval holes of another set of scissor links.

[0008] Furthermore, as a preferred embodiment, a sealing bag is fixedly fitted on the outer wall of the upper part of the external extraction pipe, and the sealing bag is a capsule that can contain cement slurry and has a certain degree of elasticity.

[0009] Furthermore, as a preferred embodiment, an external air inlet is provided on the outer wall of the lower part of the external extraction pipe, and an inner extraction pipe is embedded inside the external extraction pipe. The upper end of the inner extraction pipe is higher than the external extraction pipe, and the external air inlet can communicate with the inner extraction pipe.

[0010] Furthermore, as a preferred embodiment, the inner extraction pipe is rotatably disposed inside the outer extraction pipe, and the inner extraction pipe has an inner air inlet corresponding to the position of the outer air inlet.

[0011] Furthermore, as a preferred embodiment, the inner extraction pipe and the outer extraction pipe are unidirectionally rotatable, and the rotation direction of the inner extraction pipe toward the drilling direction of the drill bit is restricted.

[0012] Furthermore, as a preferred embodiment, a grouting groove is provided between the inner extraction pipe and the outer extraction pipe. One end of the grouting groove is a grouting hole that extends to the upper part of the inner extraction pipe, and the other end is a grouting outlet that extends into the sealing bag.

[0013] Furthermore, as a preferred embodiment, the outer extraction pipe is movably connected to the central sleeve, and the portion of the outer extraction pipe near its upper end is provided with an outer extraction pipe thread, which can be threadedly engaged with the central sleeve.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] In this invention, each set of scissor links is distributed along the formation fractures where gas leaks out. Each drill rod is sequentially drilled into the formation along the formation fractures along the side sleeve. Grout is injected into the formation through the drill rods to seal the entire formation fracture, prevent gas leakage, and stabilize the drill rods and scissor links. Furthermore, adjacent sets of scissor links can rotate at a certain angle, so that all scissor links can be connected into a curve to adapt to the distribution of drill rods along formation fractures of different shapes.

[0016] In this invention, after the drill rod enters the formation, the corresponding scissor link can be nailed to the ground surface, and after the external extraction pipe enters the formation, it can be fixed in the corresponding scissor link, thereby connecting with each drill rod and each set of scissor links to form a whole, so as to improve the stability of the external extraction pipe.

[0017] In this invention, when the inner extraction pipe is rotated to the point where the inner air inlet and the outer air inlet are misaligned, the inner air inlet is sealed to prevent debris from clogging the inner extraction pipe during the drilling process of the outer and inner extraction pipes into the formation. After the outer extraction pipe is drilled into the formation, the borehole opened by the drill bit can be sealed by grouting the sealing bag to prevent gas leakage. Attached Figure Description

[0018] Figure 1 A schematic diagram of a drilling-type external gas leakage recovery device for underground coal gasification.

[0019] Figure 2 A schematic diagram of its structure;

[0020] In the diagram: 1. Scissor lift linkage; 2. Central sleeve; 3. External extraction pipe; 31. External extraction pipe thread; 32. External air inlet; 33. Grouting groove; 34. Grouting hole; 35. Grout outlet; 4. Side sleeve; 5. Drill rod; 51. Pin; 52. Oval hole; 53. Drill rod thread; 6. Drill bit; 7. Internal extraction pipe; 71. Internal air inlet; 8. Sealing bag. Detailed Implementation

[0021] Please see Figure 1 In this embodiment of the invention, an underground coal gasification mining equipment using a drilling-type coal gas leakage recovery device includes a scissor link 1. The scissor link 1 consists of two links rotatably connected together at their centers. Multiple sets of scissor links 1 are hinged together at both ends. A central sleeve 2 is rotatably provided at the center of the central scissor link 1. An external extraction pipe 3 passes through the central sleeve 2. A drill bit 6 is fixed at the lower end of the external extraction pipe 3. Side sleeves 4 are rotatably provided at the centers of the remaining scissor links 1. A drill rod 5 passes through each side sleeve 4.

[0022] In this embodiment, the drill rod 5 is movably connected to the side sleeve 4. The upper part of the drill rod 5 is provided with a drill rod thread 53, which can be threadedly engaged with the side sleeve 4. The drill rod 5 can penetrate the side sleeve 4 and drill into the formation. When the drill rod 5 drills to a depth that the drill rod thread 53 contacts the side sleeve 4, the drill rod 5 and the side sleeve 4 are threaded together, thereby restricting the vertical displacement of the drill rod 5 and the corresponding scissor link 1. That is to say, after the drill rod 5 drills into the formation, it can nail the corresponding scissor link 1 to the ground surface. When each drill rod 5 nails the scissor link 1 to the ground surface, each group of scissor links 1 is connected as a whole to improve the stability of the external extraction pipe 3.

[0023] In this embodiment, the drill rod 5 is a hollow tube with drill lines at the bottom and extending through the top and bottom. After the drill rod 5 is drilled into the formation, grout can be injected into the formation through the drill rod 5 to form a seal, prevent gas leakage, and stabilize the drill rod 5 and the scissor lift rod 1.

[0024] In this embodiment, of the two connecting rods constituting the scissor link 1, one has pins 51 at both ends, and the other has oval holes 52 at both ends. The pins 51 of adjacent scissor links 1 can be slidably connected to the oval holes 52 of another set of scissor links 1. That is to say, two adjacent sets of scissor links 1 can rotate at a certain angle, so that all scissor links 1 can be connected into a curve to adapt to the distribution of drill pipe 5 along formation fractures of different shapes.

[0025] In this embodiment, a sealing bag 8 is fixedly fitted onto the outer wall of the external extraction pipe 3 near the upper part. The sealing bag 8 is a capsule that can contain cement slurry and has a certain degree of elasticity. After the external extraction pipe 3 is drilled into the formation, the sealing bag 8 is grouted to expand it and seal the borehole opened by the drill bit 6, preventing gas leakage.

[0026] Please see Figure 2 In this embodiment, an external air inlet 32 ​​is provided on the outer wall of the lower part of the external extraction pipe 3. An internal extraction pipe 7 is embedded in the external extraction pipe 3. The upper end of the internal extraction pipe 7 is higher than the external extraction pipe 3. The external air inlet 32 ​​can communicate with the internal extraction pipe 7.

[0027] In this embodiment, the inner extraction pipe 7 is rotatably disposed inside the outer extraction pipe 3, and the inner extraction pipe 7 has an inner air inlet 71 at the position corresponding to the outer air inlet 32. When the inner extraction pipe 7 rotates to the point where the inner air inlet 71 is misaligned with the outer air inlet 32, the inner air inlet 71 is sealed to prevent debris from clogging the inner extraction pipe 7 during the drilling process of the outer extraction pipe 3 and the inner extraction pipe 7 into the formation.

[0028] In this embodiment, the inner extraction pipe 7 and the outer extraction pipe 3 are unidirectionally rotatable, and the rotation direction of the inner extraction pipe 7 toward the drilling direction of the drill bit 6 is restricted. This ensures that the inner extraction pipe 7 and the outer extraction pipe 3 will not rotate relative to each other during drilling into the formation.

[0029] In this embodiment, a grouting groove 33 is provided between the inner extraction pipe 7 and the outer extraction pipe 3. One end of the grouting groove 33 is a grouting hole 34 extending to the upper part of the inner extraction pipe 7, and the other end is a grout outlet hole 35 extending into the sealing bag 8. Grout can be injected into the sealing bag 8 through the grouting hole 34.

[0030] In this embodiment, the outer extraction pipe 3 is movably connected to the central sleeve 2. The portion of the outer extraction pipe 3 near its upper end is provided with an outer extraction pipe thread 31, which can be threadedly engaged with the central sleeve 2. That is, after the outer extraction pipe 3 is drilled into the formation, it can be fixed in the corresponding scissor link 1, thereby forming a whole with each drill pipe 5 and each set of scissor links 1 to improve the stability of the outer extraction pipe 3.

[0031] In practice, each set of scissor lift rods 1 is distributed along the formation fractures where gas is leaking. Each drill rod 5 is then drilled into the formation along the side sleeve 4 until the drill rod thread 53 is threadedly connected and fixed to the side sleeve 4. Cement grout with a water-cement ratio of 1:1 is then injected into the formation through the drill rod 5 to seal the formation fractures, prevent gas leakage, and stabilize the drill rod 5 and scissor lift rods 1. After the cement grout has stabilized, the inner extraction pipe 7 and the outer extraction pipe 3 are drilled together into the formation along the central sleeve 2 until the gas layer is reached. The outer extraction pipe thread 31 is threadedly connected and fixed to the central sleeve 2. Cement slurry with a water-cement ratio of 1:1 is injected into the sealing bag 8 through the grouting hole 34 along the grouting groove 33, so that the sealing bag 8 expands to seal the drill hole opened by the drill bit 6 and fixes the outer extraction pipe 3 into the drill hole. After the cement slurry is stable, the inner extraction pipe 7 is rotated in the opposite direction of the drilling direction of the drill bit 6 so that the inner air inlet 71 is aligned with the outer air inlet 32. The upper end of the inner extraction pipe 7 is connected to the extraction device to extract the gas leaking from the formation fissure.

[0032] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A drilling-type external gas leakage recovery device for underground coal gasification, characterized in that, Includes a scissor link (1), which is composed of two links rotatably connected together at their centers. Multiple sets of scissor links (1) are hinged together at both ends. A central sleeve (2) is rotatably provided at the center of the scissor link (1) located at the center. An external extraction pipe (3) passes through the central sleeve (2). A drill bit (6) is fixed at the lower end of the external extraction pipe (3). Side sleeves (4) are rotatably provided at the centers of the remaining scissor links (1). A drill rod (5) passes through each side sleeve (4). The outer wall of the external extraction pipe (3) near the top is fixedly fitted with a sealing bag (8), which is a bag that can contain cement slurry and has a certain elasticity. An external air inlet (32) is provided on the outer wall near the lower part of the external extraction pipe (3). An internal extraction pipe (7) is embedded in the external extraction pipe (3). The upper end of the internal extraction pipe (7) is higher than the external extraction pipe (3). The external air inlet (32) can communicate with the internal extraction pipe (7). The inner extraction pipe (7) is rotatably disposed inside the outer extraction pipe (3), and the inner extraction pipe (7) has an inner air inlet (71) at the position corresponding to the outer air inlet (32). The inner extraction pipe (7) is unidirectionally rotatably connected to the outer extraction pipe (3), and the rotation direction of the inner extraction pipe (7) toward the drill bit (6) is restricted.

2. The underground gasification and external gas leakage recovery equipment according to claim 1, characterized in that, The drill rod (5) is movably connected to the side sleeve (4). The drill rod (5) near the upper end is provided with a drill rod thread (53), and the drill rod thread (53) and the side sleeve (4) can be threadedly engaged.

3. The underground gasification and gas leakage recovery equipment using drilling technology as described in claim 1, characterized in that, The drill rod (5) is a hollow tube with drill marks at the bottom and running through the top and bottom.

4. The underground gasification and gas leakage recovery equipment using drilling technology as described in claim 1, characterized in that, Of the two connecting rods that make up the scissor link (1), one has pins (51) at both ends, and the other has oval holes (52) at both ends. The pins (51) between adjacent scissor links (1) can be slidably connected to the oval holes (52) of another set of scissor links (1).

5. The underground gasification and gas leakage recovery equipment using drilling technology according to claim 1, characterized in that, A grouting groove (33) is provided between the inner extraction pipe (7) and the outer extraction pipe (3). One end of the grouting groove (33) is a grouting hole (34) that extends to the upper part of the inner extraction pipe (7), and the other end is a grouting outlet hole (35) that extends into the sealing bag (8).

6. The underground gasification and gas leakage recovery equipment using drilling technology as described in claim 1, characterized in that, The external extraction pipe (3) is movably connected to the central sleeve (2). The external extraction pipe (3) has an external extraction pipe thread (31) near its upper end. The external extraction pipe thread (31) and the central sleeve (2) can be threaded together.

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