CN114233370B - Integrated drainage method for gas drainage borehole collapse repair and interconnection - Google Patents

Abstract

The invention relates to an integrated extraction method for collapse restoration and interconnection of gas extraction drilling holes, which belongs to the technical field of coal mine safety, and aims at the difficult problem of low gas extraction efficiency of a mine caused by easy deformation and easy collapse of gas extraction drilling holes in a soft coal layer, and the special universal joint is adopted to connect a drill rod and a dredging drill bit, so that the drill rod and the dredging drill bit are driven to rotate by a drilling machine to cut coal bodies at the collapsed positions, thereby recovering the functional properties of the gas extraction drilling holes; further, the collapsed gas extraction drilling holes and the adjacent gas extraction drilling holes are interconnected through a special method of matching the interconnection drill bit with the screen hole pipe, the screen hole pipe is reserved in the interconnection drilling holes, the permeability of a coal body in the influence range of the gas extraction drilling holes is improved, the gas migration path in the coal body is increased, and the mine gas extraction efficiency is improved.

Description

Integrated drainage method for gas drainage borehole collapse repair and interconnection

technical field

The invention belongs to the technical field of coal mine safety, and relates to an integrated gas drainage method for gas drainage borehole collapse repair and interconnection.

Background technique

Recently, the global market has fallen into "coal shortage, gas shortage, oil shortage, and electricity shortage", which has caused the prices of natural gas, thermal coal, and electricity to break through record highs. The extremely severe global energy supply situation has put enormous pressure on our country. China proceeds from the overall situation to increase coal production and supply in a timely manner to ensure the development of domestic production and the well-being of the people. Coal has always played an important role in ensuring my country's energy security. Coal mine gas, also known as "coal bed methane", is a gas with methane as the main component that exists in the coal seam of the mine. It will desorb and seep from the solid surface of the coal to the underground with the advancement of the underground mining project and the mining of coal. mining space. When the concentration of gas gas is within a certain range, if there is an ignition source, it will inevitably lead to the occurrence of gas explosion accidents in coal mines. At the same time, coal and gas outburst accidents caused by gas have long been the main factor restricting the development of my country's advanced coal mining technology. In addition, when the gas is discharged into the atmosphere from underground coal mines, it will aggravate the greenhouse effect in the mining area. Therefore, in order to ensure the safe and efficient production of mines, my country's coal mines mainly adopt the method of gas drainage to control gas disasters. However, due to the extremely complex geological conditions for gas occurrence in coal mines in my country, most mine coal seams are high gas or coal and gas outburst coal seams, and the coal seams are relatively soft. Therefore, during the service period of gas drainage drilling, they are often deformed seriously and are prone to collapse. , and then block the gas drainage boreholes, affecting the mine gas drainage efficiency. Therefore, carrying out relevant technical research and repairing the collapsed gas drainage boreholes is one of the hot pursuits of coal mine safety workers in my country in recent years. At the same time, the collapse time of gas drainage boreholes constructed in soft coal seams with high gas or coal and gas outbursts is not fixed, and it is extremely sudden and accidental in terms of the entire mining face, so this condition is considered Under the premise of repairing the collapse of the gas drainage boreholes, the key to effectively improve the mine gas drainage efficiency is to connect the corresponding gas drainage boreholes and form a criss-crossing borehole network.

Contents of the invention

In view of this, the purpose of the present invention is to provide an integrated gas drainage method for gas drainage borehole collapse repair and interconnection, aiming at the easy deformation and collapse of gas drainage boreholes in soft coal seams, and the sudden collapse of the collapse itself. In order to solve the problem of mine gas drainage efficiency caused by sporadic and accidental problems, through the cooperation of dredging drill bits and repair pipelines, the coal body at the collapsed place can be penetrated to dredge the gas drainage drilling holes; Cooperate, drill the coal body between the drill holes adjacent to the gas drainage drill hole, and then form a drill hole network between the gas drainage drill hole that collapsed and the adjacent drill holes, and further improve the impact of the gas drainage drill hole. The permeability characteristics of the coal body within the range can improve the gas drainage efficiency of the mine.

To achieve the above object, the present invention provides the following technical solutions:

An integrated gas drainage method for gas drainage borehole collapse repair and interconnection, comprising the following steps:

S1: Construct gas drainage boreholes in the coal seam, and after the drilling is completed, immediately block and install drainage pipes; then connect the drainage pipes through connecting hoses, so that the gas in the boreholes can pass through the drainage pipes. Pipes and connecting hoses are used to enter the gas drainage pipeline; after a certain period of time, if the gas concentration in a certain gas drainage borehole is found to be close to 0, while the gas concentration in the adjacent borehole is close to that of the coal seam If the concentration of inner gas is low, it can be determined that a collapse has occurred in the gas drainage borehole; then the connection between the tee pipe and the connecting hose is removed, and the borehole peeper is placed in the gas drainage borehole to detect and determine the occurrence of the collapse. Then connect the four-way with the connecting hose, the water and slag removal device, and the connecting flange respectively, and put the PE repair pipeline into the gas drainage borehole through one end of the T-shaped tee and the other end of the four-way Then, connect the dredging drill bit with the dredging end drill pipe, the connecting drill pipe, and the tail drill pipe through several universal joints, and clamp the tail drill pipe through the drill pipe clamping device on the drilling rig ;

S2: Then, connect the isolation bag with one end of the T-shaped tee and the outer ring of the tail bearing, and at the same time connect the other end of the T-shaped tee with the compressed air; then, turn on the drilling rig and the compressed air to drive the explosion-proof motor The tail drill pipe, the connecting drill pipe, the dredging end drill pipe and the dredging bit rotate to cut the coal body at the collapsed place; the compressed air flows through the PE repair pipeline to drive the coal chips cut by the dredging bit to the connecting The hose and PE repair the annular space in the pipeline until it enters the water and slag removal device connected to the lower end of the four-way under the action of gravity, and the gas gas flowing out during the drilling process of the dredge drill bit is in the drainage pipe network Under the action of system negative pressure, it flows into the upper end of the cross through the annular space connecting the hose and the PE repair pipeline, and then enters the gas drainage pipeline;

S3: After the unblocking drill bit has drilled a certain distance, stop the drilling machine immediately, and turn off the compressed air, remove the connection between the PE repair pipeline and the T-shaped tee, and then push the PE repair pipeline to the bottom of the gas drainage drilling hole Move, if the movement is blocked, it means that the coal body at the collapsed place has not finished chipping, then connect the PE repair pipeline to the T-shaped tee at this time; then turn on the drilling rig again to make the explosion-proof motor drive the tail drill pipe and connect the drill pipe , dredge the end drill pipe and dredge the drill bit to rotate, and then cut the collapsed coal body again; until the PE repair pipeline is delivered to the gas drainage borehole, the length of the PE repair pipeline entering the gas drainage borehole If the length of the gas drainage borehole is similar to that of the gas drainage borehole, it indicates that the collapsed part of the gas drainage borehole has been completely repaired; at this time, the connection between the isolation bag and the tail bearing can be removed, and the connection between the drill pipe clamping device and the tail drill pipe can be removed , Quickly remove the drill pipes, dredging bits, dredging end drill pipes, and PE repair pipelines that enter the gas drainage boreholes from the gas drainage boreholes;

S4: Place the interconnection guide pipeline to be gradually transported to the position that needs to be interconnected in the gas drainage borehole, and then connect the screen pipe and the connecting pipe through threads, and transport it to the position that needs to be interconnected in the gas drainage borehole ; Connect the interconnected drill bit with the interconnected end drill pipe, and connect several connected drill pipes with the interconnected end drill pipe through the universal joint, and gradually send the interconnected drill bit through the connection of the interconnected drill pipe and the universal joint to the place that needs to be interconnected At the position, since the front end of the interconnection guide pipeline has a certain inclination angle, the interconnection drill bit can drill along the direction of the inclination angle, so that the gas drainage borehole that has completed the collapse repair is interconnected with the adjacent borehole;

S5: The function of the interconnection guide pipeline is the same as that of the PE repair pipeline in the aforementioned collapse repair, and the connection method is also the same; when the interconnection operation is performed, the drilling rig is turned on to make the explosion-proof motor drive the tail drill pipe, connect the drill pipe, the universal knot, and the interconnection end The drill pipe and the interconnected drill bit rotate to cut and drill the coal body between the gas drainage boreholes; the cut coal chips are transported to the gas drainage borehole through the annular space of the screen pipe and the interconnected guide pipeline. In the water and slag removal device at the orifice, the gas released from the coal body during the drilling process of the interconnected drill bit enters the gas drainage pipeline at the upper end of the cross;

S6: With the continuous drilling of the interconnected drill bit, the sieve hole pipe is driven into the coal body. After the interconnected drill bit reaches the predetermined position, the push-pull function of the drilling rig is turned on to move the drill pipe to the direction of the drilling hole, thereby making the sieve The hole tube is stuck in the interconnected boreholes; according to the actual engineering situation on site, S4~S6 can be repeated to construct 2~3 interconnected boreholes, so that the interconnected boreholes will connect the gas drainage boreholes that have completed the collapse and repair with the adjacent ones. 1 to 2 gas drainage boreholes are interconnected to form a network of gas drainage boreholes; after the construction of the interconnected boreholes is completed, the interconnected drill bit, drill pipe, and interconnected guide pipeline can be withdrawn, and the connecting hose and tee Connect the other two ends of the three-way pipe to the gas drainage pipeline and the water and slag removal device respectively, and then continue to implement gas drainage.

Further, step S1 specifically includes the following steps:

S11: Construct gas drainage boreholes in the transportation trough or return air trough of the underground mining face of the coal mine. After the construction is completed, place drainage pipes in the gas drainage boreholes. Further, the drainage pipes are It is made of PVC or PE, and its antistatic and flame-retardant properties meet the practical requirements of coal mines; then, use polymer materials or other sealing materials to seal the gas drainage drilling, and the sealing section is from the roadway wall to the drilling hole The depth and length of the bottom of the hole must be more than 20m; after the gas drainage borehole is sealed, the connecting hose will be connected to the drainage pipe, so that the gas in the borehole can enter the gas through the drainage pipe and the connecting hose. In the drainage pipeline; further, the gas drainage pipeline is finally connected with the gas drainage pump installed on the ground, and the negative pressure is provided by the gas drainage pump, so that the gas gas is discharged in the pipeline network composed of the drainage pipelines laid underground in the coal mine. flow; open a sampling hole on the surface of the connecting hose or the drainage pipe exposed outside the gas drainage borehole, and further, the function of the sampling hole is to provide a special instrument for measuring the gas concentration of the borehole to collect gas channel;

S12: After the completed gas drainage boreholes are merged into the pipeline network composed of underground gas drainage pipelines in the coal mine, the gas extraction starts, and then the concentration of the gas flowing out of the boreholes is detected through the sampling holes every day; When it is found that the gas concentration in a certain gas drainage borehole is close to 0, and the gas concentration value of the adjacent borehole is close to the concentration of the original gas gas in the coal seam, it can be determined that the gas concentration in the gas drainage borehole has occurred. collapse;

S13: Then, remove the connection between the tee pipe and the connecting hose, place the borehole peeper in the gas drainage borehole, detect and determine the location of the collapse, and record the distance between the location and the gas drainage borehole distance; further, according to the distance, select a PE repair pipeline with a length slightly higher than this value; further, the opening of the PE repair pipeline has a certain length of reduced diameter section, and its function is to increase the air pressure in the PE repair pipeline The flow rate is high, so that the coal chips cut by the dredging drill bit can be sprayed into the annular space between the PE repair pipeline and the connecting hose; then the four-way is connected with the connecting hose, the water and slag removal device, and the connecting flange respectively, and further , the outer surface of the connecting flange and the PE repair pipeline needs to be cushioned with a sealing rubber ring, its function is to prevent the air in the roadway from entering the gas through the gap between the outer surface of the PE repair pipeline and the inner ring of the connecting flange At the same time, it also prevents the coal slag or coal powder generated during the subsequent dredging drill drilling process from entering the roadway through the gap between the outer surface of the PE repair pipeline and the inner ring of the connecting flange to affect the health of the operators; The repair pipeline is placed into the gas drainage borehole through one end of the T-shaped tee and the other end of the cross until it reaches the location where the collapse occurs; further, the other end of the T-shaped tee is connected to the compressed air, An isolation bag needs to be installed at the end where the PE repair pipeline is inserted; the isolation bag is tightly attached to the surface of the straight pipe of the T-shaped tee through iron wire rolling, and its function is to cooperate with the tail bearing set on the tail drill pipe. During the rotation of the tail drill pipe, the isolation bag can also reduce the leakage of pressurized air; at the same time, the overall size of the isolation bag must be able to adapt to the displacement caused by the PE repair pipeline entering the gas drainage borehole;

S14: Then, connect the dredging drill bit with the dredging end drill pipe, the connecting drill pipe, and the tail drill pipe through several universal joints, and clamp the tail drill pipe through the drill pipe clamping device on the drilling rig; further, the dredge drill bit It is threadedly connected with the dredging end drill rod; the dredging end drill rod and the connecting drill rod are also provided with bearings, and the inner ring of the bearing is fixed on the outer wall of the dredging end drill rod and the connecting drill rod; further, the The function of the above-mentioned bearing is that the rotary motion of the dredging end drill pipe and the connecting drill pipe will drive the inner ring of the bearing to rotate, and the balls in the bearing are in contact with the outer ring of the bearing, which can effectively prevent the rotational movement of the dredging end drill pipe and the connecting drill pipe During the process, it collides with the inner wall of the PE repair pipeline to affect its rotational movement; further, the function of the universal joint is to make the dredging drill bit and the dredging end drill pipe, and the connecting drill pipe in the case of bending of the PE repair pipeline , can still produce rotary motion under the action of the drilling rig, so as to ensure that the dredging drill bit can continuously and stably cut the collapsed coal body.

Further, step S2 specifically includes the following steps:

S21: Further, the outer ring of the tail bearing is provided with a groove, so that the isolation bag can be fixed and tightened by iron wire in the groove of the outer ring of the tail bearing; the inner ring of the tail bearing is fixed on the tail drill pipe On the outer wall of the tail bearing, the inner ring of the tail bearing will rotate with it during the rotation of the tail drill pipe; connect the isolation bag with one end of the T-shaped tee and the outer ring of the tail bearing, and at the same time connect the other end of the T-shaped tee One end is connected to the compressed air;

S22: Then, turn on the drilling rig and the compressed air, so that the explosion-proof motor drives the tail drill pipe, connects the drill pipe, dredges the end drill pipe and dredges the drill bit to rotate, and then cuts the collapsed coal body; the gas pressure of the compressed air is 0.5 ~0.7MPa, it enters the PE repair pipeline through the T-shaped tee, and can drive the coal chips cut by the dredging drill bit to the annular space between the connecting hose and the PE repair pipeline; and the gas pressure in the extraction pipeline is lower than the atmospheric pressure in the roadway, while the compressed air gas pressure in the PE repair pipeline is higher than the atmospheric pressure in the roadway, so the coal chips cut by the dredging bit will be in the second Driven by the pressure difference, it connects the hose and the annular space in the PE repair pipeline until it enters the water and slag removal device connected to the lower end of the four-way under the action of gravity, so as to protect the health of the workers at the construction site in the roadway;

S23: At the same time, during the drilling process of the dredging drill bit, the gas gas accumulated behind the collapse due to blockage will flow to the direction of the gas drainage borehole due to the change in the sealing of the coal body at the collapse site, so the gas gas will Under the action of the negative pressure of the drainage pipe network system, it flows into the upper end of the cross through the annular space connecting the hose and the PE repair pipeline, and then enters the gas drainage pipeline to effectively prevent the gas from entering the roadway.

Further, step S3 specifically includes the following steps:

S31: When the dredging bit rotates to cut the collapsed coal body, simultaneously start the push-pull function of the drilling rig, so that the dredging bit can also move towards the bottom of the gas drainage drilling hole; after the dredging bit drills a certain distance, stop the drilling machine immediately, and Turn off the pressure air, remove the connection between the PE repair pipeline and the T-shaped tee, and then push the PE repair pipeline to move towards the bottom of the gas drainage drilling hole. If the movement is blocked, it means that the coal body at the collapsed site has not been cut. , then connect the PE repair pipeline to the T-shaped tee at this time, continue to turn on the drilling rig, make the explosion-proof motor rotate to drive the dredging drill to rotate, and at the same time turn on the push-pull function of the drilling rig, so that the dredging bit can also drill holes for gas drainage The direction of the bottom of the hole moves;

S32: Repeat S31 until the PE repair pipeline is delivered to the gas drainage borehole, and the length of the PE repair pipeline entering the gas drainage borehole is similar to the length of the gas drainage borehole, indicating gas drainage The collapsed parts of the borehole have all been repaired; at this time, the connection between the isolation bag and the tail bearing can be removed, the connection between the drill pipe clamping device and the tail drill pipe can be removed, and the drill pipe entering the gas drainage borehole can be quickly dredged and dredged. The drill bit and the dredging end drill pipe exit the gas drainage borehole.

Further, step S4 specifically includes the following steps:

S41: Place the interconnection guide pipeline and gradually transport it to the position in the gas drainage borehole that needs to be interconnected. Further, the front end of the interconnection guide pipeline has a certain inclination angle, which allows the interconnection drill bit to enter the coal mine along the direction of the inclination angle. In the body, the gas drainage borehole that has completed the collapse repair is interconnected with the adjacent borehole; at the same time, the interconnection guide pipeline is connected with the four-way and T-shaped tee, and its function is the same as that of the PE repair pipe in the collapse repair operation. Road works the same way;

S42: Finally, connect the interconnected drill bit with the interconnected end drill pipe, and connect several drill pipes with the interconnected end drill pipe through a universal joint, and at the same time connect the screen pipe and the connecting pipe through threads; gradually connect the interconnected drill bit through The connection of the drill pipe and the universal joint is sent to the position that needs to be interconnected; further, two springs are provided in the 180° direction of the connecting pipe, and when the interconnected end drill pipe carrying the interconnected drill bit is not combined with the connecting pipe, the The two springs are in a stretched state, which can constrain nearly a quarter of the arc stopper on the movable limit block in the arc groove on the inner wall of the connecting pipe; the interconnected end drill pipe carrying the interconnected drill bit When combined with the connecting pipe, the balls set in the groove of the circumferential fixed stopper on the drill pipe at the interconnection end contact with the inclined surface on the movable stopper, and then push the movable stopper to move toward the direction of the hole depth, so that the hook will The movable limit block is fixed; at the same time, during the rotary drilling process of the interconnected drill bit and the drill pipe at the interconnected end, since there are balls in the groove of the circumferential fixed stopper, it can roll in the groove, thus ensuring that the interconnected drill bit and the drill pipe at the interconnected end Interconnected end drillpipe rotary drilling continues.

The beneficial effects of the present invention are:

The present invention proposes an integrated gas drainage method of gas drainage borehole collapse repair and interconnection, aiming at the problem that the gas drainage boreholes in the soft coal seam are easy to deform and collapse, resulting in low efficiency of mine gas drainage, using a unique The way of connecting the drill pipe and the dredging bit with the unique universal joint, the drilling rig drives the drill pipe and the dredging bit to rotate and then cuts the collapsed coal body, thereby restoring the functional properties of the gas drainage borehole; furthermore, through the unique interconnected drill bit The method of cooperating with the sieve pipe interconnects the collapsed gas drainage borehole with the adjacent gas drainage borehole, and keeps the sieve pipe in the interconnected borehole, which increases the influence range of the gas drainage borehole The permeability characteristics of the inner coal body increase the path of gas migration in the coal body, which is conducive to improving the efficiency of mine gas drainage. Compared with the previous methods, the integrated drainage method of gas drainage drilling collapse repair and interconnection has advantages The following advantages:

1. The integrated gas drainage method of the present invention, which integrates gas drainage borehole collapse repair and interconnection, fully considers the problem that gas drainage boreholes in soft coal seams are easy to deform and collapse, and uses a unique universal knot to dredge The drill bit is connected to the connecting drill pipe and placed in the PE repair pipeline, so as to ensure that the drilling and cutting of the collapsed coal body under any drilling deformation condition can be realized during the rotation process of the drilling rig driving the drill pipe and the dredging drill bit, thus effectively Dredge the collapsed gas drainage borehole.

2. The gas drainage borehole collapse repair and interconnection integrated drainage method provided by the present invention can also use the method of cooperating with the unique interconnection drill bit and the screen pipe after completing the dredging and repair of the collapsed gas drainage borehole , connect the collapsed gas drainage borehole with the adjacent gas drainage borehole, and leave the sieve pipe in the interconnected borehole, that is, in the subsequent drainage process, the adjacent gas drainage borehole When a collapse occurs, the interconnected boreholes can still provide a good channel for the outflow of gas gas, which improves the permeability characteristics of the coal body within the influence range of the gas drainage boreholes and increases the path of gas migration in the coal body, which is beneficial to Improve the efficiency of mine gas drainage.

3. The integrated drainage method for gas drainage borehole collapse repair and interconnection provided by the present invention uses PE material pipelines as the drilling channels in the process of collapsed gas drainage borehole repair and interconnection operations, which can effectively Ensure the stable and continuous drilling operation, and connect the T-shaped tee with the compressed air to realize the effective removal of drilling cuttings; and the cross set on the connecting hose is also connected to the drainage pipeline laid underground, which can It realizes the effective transportation of coal body fugitive gas in the process of gas drainage drilling repair and interconnection operation, and eliminates the threat to personnel safety caused by gas gushing into the roadway.

Other advantages, objects and features of the present invention will be set forth in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the investigation and research below, or can be obtained from It is taught in the practice of the present invention. The objects and other advantages of the invention may be realized and attained by the following specification.

Description of drawings

In order to make the purpose of the present invention, technical solutions and advantages clearer, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

Fig. 1 is a schematic diagram of device connection in the gas drainage stage of step S1 of the method;

Fig. 2 is a schematic diagram of device connection in the detection and dredging stage of step S1 of the method;

Fig. 3 is a structure diagram of the universal joint;

Fig. 4 is the schematic diagram of connecting drill pipe structure;

Fig. 5 is a structural diagram of interconnected end drill pipes;

Figure 6 is a schematic diagram of a drilling scene for gas drainage;

Fig. 7 is a schematic diagram of interconnection guide pipelines.

Reference signs: gas drainage drilling 1, drainage pipe 2, connecting hose 3, tee pipe 4, cross 5, connecting flange 6, PE repair pipeline 7, T-shaped tee 8, dredging drill bit 9. Dredge end drill pipe 10, connecting drill pipe 11, tail drill pipe 12, universal knot 13, drill pipe clamping device 14, roadway wall 15, drilling hole bottom 16, sealing rubber ring 17, collapsed part 18, Isolation bag 19, tail bearing 20, drilling rig 21, bearing inner ring 22, ball 23, bearing outer ring 24, bearing cage 25, vent hole 26, explosion-proof motor 27, interconnection guiding pipeline 28, screen hole pipe 29, connecting pipe 30. Interconnected drill bits 31, interconnected end drill rods 32, springs 33, movable stoppers 34, circumferential fixed stoppers 35, balls 36, drag hooks 37, sieve holes 38, and moving tracks 39.

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the diagrams provided in the following embodiments are only schematically illustrating the basic concept of the present invention, and the following embodiments and the features in the embodiments can be combined with each other in the case of no conflict.

Wherein, the accompanying drawings are for illustrative purposes only, and represent only schematic diagrams, rather than physical drawings, and should not be construed as limiting the present invention; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, Enlargement or reduction does not represent the size of the actual product; for those skilled in the art, it is understandable that certain known structures and their descriptions in the drawings may be omitted.

In the drawings of the embodiments of the present invention, the same or similar symbols correspond to the same or similar components; , "front", "rear" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred devices or elements must It has a specific orientation, is constructed and operated in a specific orientation, so the terms describing the positional relationship in the drawings are for illustrative purposes only, and should not be construed as limiting the present invention. For those of ordinary skill in the art, the understanding of the specific meaning of the above terms.

Please refer to Figs. 1 to 7, the present invention provides an integrated gas drainage method for gas drainage borehole collapse repair and interconnection, including the following steps:

S1: The gas drainage drilling 1 is constructed in the coal seam, and after the drilling is completed, it is immediately blocked and the drainage pipe 2 is installed; then connected to the drainage pipe 2 through the connecting hose 3, so that The gas enters the gas drainage pipeline through the drainage pipe 2 and the connecting hose 3; after a certain period of time, if the gas concentration in a certain gas drainage borehole 1 is found to approach If the gas concentration value is close to the gas concentration in the coal seam, it can be determined that a collapse has occurred in the gas drainage borehole 1; then remove the connection between the tee pipe 4 and the connecting hose 3, and place the borehole peeper in the gas Drain the borehole, detect and determine the location of the collapse; then connect the cross 5 with the connecting hose 3, the water and slag removal device, and the connecting flange 6, and connect the PE repair pipeline 7 through the T-shaped tee 8 One end of the four-way 5 and the other end of the cross 5 are put into the gas drainage borehole 1 until they reach the position where the collapse occurs; then, the dredging drill bit 9 and the dredging end drill pipe 10, the connecting drill pipe 11 and the tail drill pipe 12 are passed through Several universal joints 13 are connected, and the tail drill pipe 12 is clamped by the drill pipe clamping device 14 on the drilling rig 21; step S1 specifically includes the following steps:

S11: Construct the gas drainage borehole 1 in the transportation trough or return air trough of the mining face in the coal mine. After the construction is completed, place the drainage pipe 2 in the gas drainage borehole. Optionally, the drainage pipe 2 is made of PVC or PE, and its antistatic and flame-retardant properties meet the practical requirements of underground coal mines; Plugging, the depth and length of the sealing section 14 from the roadway wall 15 to the bottom of the borehole 16 must be more than 20m; after the gas drainage drilling 1 is sealed, the connecting hose 3 will be connected to the drainage pipe 2 , so that the gas in the borehole enters into the gas drainage pipeline through the drainage pipe 2 and the connecting hose 3 . Optionally, the gas extraction pipeline is finally connected with a gas extraction pump installed on the ground, and the gas extraction pump provides negative pressure to make the gas flow in the pipeline network composed of extraction pipelines laid underground in the coal mine; A sampling hole is provided on the surface of the connection hose 3 or the extraction pipe 2 exposed outside the gas extraction borehole 1 . Optionally, the function of the sampling hole is to provide a channel for collecting methane gas for a special instrument for measuring the concentration of gas extracted from the borehole;

S12: After the completed gas drainage borehole 1 is merged into the pipeline network composed of underground gas drainage pipelines in the coal mine, the gas drainage is started, and then the concentration of the gas flowing out of the borehole is detected through the sampling hole every day ; When it is found that the gas concentration in a gas drainage borehole is close to 0, and the gas concentration value of the adjacent borehole is close to the original gas concentration in the coal seam, it can be determined that the gas concentration in the gas drainage borehole collapsed;

S13: Then remove the connection between the tee pipe 4 and the connecting hose 3, place the borehole peeper in the gas drainage borehole, detect and determine the location of the collapse, and record the position and the opening of the gas drainage borehole 1 Optionally, according to the distance, select the PE repair pipeline 7 whose length is slightly higher than this value; optionally, the opening of the PE repair pipeline 7 has a reduced diameter section of a certain length, and its function is to improve the PE The flow rate of the pressurized gas in the repair pipeline 7 is convenient to spray the coal chips cut by the dredging drill bit 9 into the annular space between the PE repair pipeline 7 and the connecting hose 3; , the water and slag removal device, and the connecting flange 6 are connected. Optionally, the outer surface of the connecting flange 6 and the PE repair pipeline 7 needs to be cushioned with a sealing rubber ring 17, whose function is to prevent the air in the roadway from passing through The gap between the outer surface of the PE repair pipeline 7 and the inner ring of the connecting flange 6 enters the gas drainage pipeline, and at the same time prevents the coal slag or coal powder generated during the drilling process of the subsequent dredging drill bit 9 from passing through the PE repair pipeline 7. The gap between the outer surface and the inner ring of the connecting flange 6 enters the roadway and affects the health of the workers; put the PE repair pipeline 7 into the gas drainage drill through one end of the T-shaped tee 8 and the other end of the cross 5 hole 1 until it reaches the collapsed place 18; optionally, the other end of the T-shaped tee 8 is connected to the compressed air, and an isolation bag 19 needs to be installed at the end where the PE repair pipeline 7 is inserted; the isolation The bag 19 is tightly attached to the surface of the straight pipe of the T-shaped tee 8 by iron wire rolling. 19 can reduce the leakage of compressed air;

S14: Then, connect the dredging drill bit 9 with the dredging end drill pipe 10, the connecting drill pipe 11, and the tail drill pipe 12 through several universal joints 13, and clamp the tail drill pipe 12 through the drill pipe clamping device 14 on the drilling rig 21 Tight; Optionally, the dredging drill bit 9 is threadedly connected with the dredging end drill rod 10; the dredging end drill rod 10 and the connecting drill rod 11 are also provided with bearings through a bearing cage 25, and the bearings of the bearings The bearing inner ring 22 is fixed on the outer wall of the dredging end drill rod 10 and the connecting drill rod 11; optionally, the function of the bearing is that the rotary motion of the dredging end drill rod 10 and the connecting drill rod 11 will drive the bearing inner ring 22 rotates, and the ball 23 in the bearing is in contact with the outer ring 24 of the bearing, which can effectively prevent the drill pipe 10 at the dredge end and the connecting drill pipe 11 from colliding with the inner wall of the PE repair pipeline 7 during the rotational movement, thus affecting its rotational movement , The bearing is also provided with vent holes 26. Optionally, the function of the universal joint 13 is to make the dredging drill bit 9 and the dredging end drill rod 10, and the connecting drill rod 11 still able to produce the same under the action of the drilling rig 21 under the condition that the PE repair pipeline 7 is bent. Rotating movement, thereby ensuring that the dredging drill bit 9 can continuously and stably cut the coal body at the collapsed place;

S2: Then, connect the isolation bag 19 with one end of the T-shaped tee 8 and the outer ring of the tail bearing 20, and at the same time connect the other end of the T-shaped tee 8 with the compressed air; then, turn on the drilling rig 21 and the compressed air , so that the explosion-proof motor 27 drives the tail drill pipe 12, the connecting drill pipe 11, the dredging end drill pipe 10 and the dredging drill bit 9 to rotate, and then cuts the collapsed 18 coal bodies; the compressed air passes through the flow in the PE repair pipeline 7 , the coal chips cut by the dredging drill bit 9 are driven to the annular space in the connecting hose 3 and the PE repair pipeline 7, until they enter the water and slag removal device connected to the lower end of the cross 5 under the action of gravity, and the dredging The gas flowing out during the drilling of the drill bit 9 flows into the upper end of the cross through the annular space connecting the hose 3 and the PE repair pipeline 7 under the negative pressure of the drainage pipe network system, and then enters the gas drainage pipeline ; Step S2 specifically includes the following steps:

S21: Optionally, grooves are provided on the outer ring of the tail bearing 20, so that the isolation bag 19 can be fixed and tightened by iron wires in the groove of the outer ring of the tail bearing 20; The inner ring is fixed on the outer wall of the tail drill pipe 12, and the inner ring of the tail bearing 20 will rotate with it during the rotation of the tail drill pipe 12; The outer ring is connected, and the other end of the T-shaped tee 8 is connected to the compressed air at the same time;

S22: Then, turn on the drilling rig 21 and the compressed air, so that the explosion-proof motor 27 drives the tail drill pipe 12, the connecting drill pipe 11, the dredging end drill pipe 10 and the dredging drill bit 9 to rotate, and then cut the collapsed 18 coal bodies; The gas pressure of the compressed air is 0.5-0.7MPa, which enters the PE repair pipeline 7 through the T-shaped tee 8, and can drive the coal chips cut by the dredging drill bit 9 to the connecting hose 3 and the PE repair pipeline 7 The annular space inside; because the upper end of the four-way 5 is connected with the extraction pipeline, and the gas pressure in the extraction pipeline is lower than the atmospheric pressure in the roadway, and the compressed air gas pressure in the PE repair pipeline 7 is higher than that in the roadway Atmospheric pressure, so the coal chips cut by the dredging drill bit 9 will be driven by the pressure difference between the two in the annular space in the connecting hose 3 and the PE repair pipeline 7 until it enters the lower end of the four-way 5 under the action of gravity. In the water and slag removal device, so as to protect the health of the workers at the construction site in the roadway;

S23: At the same time, during the drilling process of the dredging bit 9, the gas gas accumulated behind the collapsed part 18 due to blockage will flow to the direction of the gas drainage borehole 1 due to the change in the sealing of the coal body at the collapsed part 18, Therefore, under the negative pressure of the drainage pipe network system, the gas will flow into the upper end of the cross 5 through the annular space connecting the hose 3 and the PE repair pipeline 7, and then enter the gas extraction pipeline, effectively preventing the gas from entering the roadway Inside.

S3: After the dredging drill bit 9 has drilled a certain distance, stop the drilling machine 21 immediately, and turn off the compressed air, remove the connection between the PE repair pipeline 7 and the T-shaped tee 8, and then push the PE repair pipeline 7 to gas drainage Borehole bottom 16 direction moves, if movement is stymied, then explanation collapsed place 18 coal bodies have not cut chips, then remove the universal joint 13 on the tail drill pipe 12 at this moment, connect several connecting drill pipes 11 and universal joint 13 Connect until the dredging drill bit 9 reaches the position where the cuttings are to be drilled in the next step; then turn on the drilling machine 21 again to make the explosion-proof motor 27 drive the tail drill rod 12, the connecting drill rod 11, the dredging end drill rod 10 and the dredging drill bit 9 to rotate, and then Cut the coal body 18 at the collapsed place again; until the PE repair pipeline 7 is delivered to the gas drainage borehole 1, the length of the PE repair pipeline 7 entering the gas drainage borehole 1 is the same as that of the gas drainage borehole 1 If the lengths are similar, it indicates that the collapsed part 18 of the gas drainage borehole 1 has been completely repaired; at this time, the connection between the isolation bag 19 and the tail bearing 20 can be removed, and the connection between the drill pipe clamping device 14 and the tail drill pipe 12 can be removed. , quickly withdraw the drill pipe, dredging bit 9, and dredge end drill pipe 10 entering the gas drainage borehole 1 from the gas drainage borehole 1; step S3 specifically includes the following steps:

S31: When the dredging bit 9 rotates to cut the collapsed coal body, the push-pull function of the drilling rig 21 is simultaneously activated, so that the dredging bit 9 can also move toward the bottom 16 of the gas drainage drilling hole; after the dredging bit 9 has drilled a certain distance, Immediately stop the drilling rig 21, and turn off the compressed air, remove the connection between the PE repair pipeline 7 and the T-shaped tee 8, and then push the PE repair pipeline 7 to move toward the bottom 16 of the gas drainage borehole. If the movement is blocked, Then it shows that the 18th coal body in the collapsed place has not been cut completely, then the PE repair pipeline 7 is connected with the T-shaped tee 8 at this time, and the drilling machine 21 is continued to be opened, so that the explosion-proof motor 27 is rotated to drive the dredging drill bit 9 to rotate, and at the same time, it is opened The push-pull function of the drilling rig 21 enables the dredging drill bit 9 to move toward the bottom 16 of the gas drainage borehole;

S32: Repeat S31 until the PE repair pipeline 7 is delivered to the gas drainage borehole 1, the length of the PE repair pipeline 7 entering the gas drainage borehole 1 is similar to the length of the gas drainage borehole 1, Then it shows that the collapsed part 18 of the gas drainage borehole 1 has been completely repaired; at this time, the connection between the isolation bag 19 and the tail bearing 20 can be removed, and the connection between the drill pipe clamping device 14 and the tail drill pipe 12 can be removed, and the entering The drill pipe in the gas drainage borehole 1, the dredging drill bit 9, and the dredge end drill pipe 10 exit the gas drainage borehole.

The interconnection guide pipeline 28 is placed and gradually transported to the position in the gas drainage borehole 1 that needs to be interconnected, and then the screen pipe 29 and the connecting pipe 30 are threaded, and transported to the gas drainage borehole 1 that needs to be interconnected Connect the interconnected drill bit 31 with the interconnected end drill rod 32, and connect a number of connected drill rods 11 with the interconnected end drill rod 32 through the universal joint 13, and gradually connect the interconnected drill bit 31 through the connected drill rod 11, million The connection to the junction 13 is sent to the position that needs to be interconnected. Since the front end of the interconnection guide pipeline 28 has a certain inclination angle, the interconnection drill bit 31 can drill along the direction of the inclination angle, so that the gas drainage drilling that has completed the collapse repair 1 Interconnection with adjacent boreholes;

S41: Place the interconnection guide pipeline 28 to gradually convey to the position in the gas drainage borehole 1 that needs to be interconnected. Optionally, the front end of the interconnection guide pipeline 28 has a certain inclination angle, which can make the interconnection drill 31 along the The direction of the inclination angle enters the coal body, so that the gas drainage borehole 1 that has completed the collapse and repair is interconnected with the adjacent borehole; at the same time, the interconnection guide pipeline 28 is connected with the four-way 5 and the T-shaped three-way 8 . The function is the same as that of the PE repair pipeline 7 in the collapse repair operation;

S42: Finally, connect the interconnected drill bit 31 with the interconnected end drill rod 32, and connect several connected drill rods 11 and the interconnected end drill rod 32 through the universal joint 13, and at the same time connect the screen pipe 29 and the connecting pipe 30 through the screw thread To connect, a plurality of sieve holes 38 are distributed on the sieve pipe 29; the interconnected drill bit 31 is gradually sent to the position that needs to be interconnected by connecting the drill pipe 11 and the universal joint 13; optionally, the connecting pipe 30 Two springs 33 are provided in the inner 180° direction. When the interconnected end drill rod 32 carrying the interconnected drill bit 31 is not combined with the connecting pipe 30, the two springs 33 are in a stretched state, which can move the movable stopper 34 Nearly a quarter of the arc stop on the top is constrained in the arc groove provided on the inner wall of the connecting pipe 30, and the movable limit block 34 slides in the moving track 39; the interconnected end drill carrying the interconnected drill bit 31 When the rod 32 is combined with the connecting pipe 30, the ball 36 arranged in the groove of the circumferential fixed stopper 35 on the drill pipe 32 at the interconnection end contacts with the slope on the movable stopper 34, and then pushes the movable stopper 34 to the hole depth. direction, so that the drag hook 37 fixes the movable stopper 34; at the same time, during the rotary drilling process of the interconnected drill bit 31 and the interconnected end drill rod 32, since a ball 36 is arranged in the groove of the circumferential fixed block 35, It can generate rolling in the groove, thereby ensuring the continuous progress of the rotary drilling of the interconnected drill bit 31 and the interconnected end drill rod 32 .

S5: The interconnection guide pipeline 28 has the same function as the PE repair pipeline 7 in the aforementioned collapse repair, and the connection method is also the same; when the interconnection operation is performed, the drilling rig is turned on so that the explosion-proof motor 27 drives the tail drill pipe 12, the connecting drill pipe 11, and the universal direction 13, the interconnected end drill pipe 32 and the interconnected drill bit 31 rotate, and then cut and drill the coal body in the gas drainage borehole 1; The space moves to the water and slag removal device installed at the opening of the gas drainage borehole 1, and the gas released from the coal body during the drilling of the interconnected drill bit 31 enters the gas drainage pipeline at the upper end of the cross 5;

S6: With the continuous drilling of the interconnected drill bit 31, the screen pipe 29 is driven into the coal body, and after the interconnected drill bit 31 has drilled to the predetermined position, the push-pull function of the drill rig 21 is turned on, so that the drill pipe moves toward the hole opening , so that the screen pipe 29 stays in the interconnected boreholes; according to the actual engineering situation on site, S4-S6 can be repeated to construct 2-3 interconnected boreholes, so that the interconnected boreholes will complete the collapsed and repaired gas drainage drilling Hole 1 is interconnected with 1 to 2 adjacent gas drainage boreholes to form a network of gas drainage boreholes 1; after the construction of the interconnected boreholes is completed, the interconnected drill bit 31, drill pipe, and interconnected guide pipeline can be withdrawn 28. Connect the connecting hose 3 to the tee pipe 4, and connect the other two ends of the tee pipe 4 to the gas drainage pipeline and the water and slag removal device respectively, and then continue the gas drainage.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements, without departing from the spirit and scope of the technical solution, should be included in the scope of the claims of the present invention.

Claims (5)

1. A gas extraction borehole collapse repair and interconnection integrated extraction method is characterized in that: the method comprises the following steps:

s1: constructing a gas extraction drilling hole in the coal seam, plugging immediately after the drilling hole is constructed, and installing an extraction pipe; the gas in the drill hole enters the gas extraction pipeline through the extraction pipe and the connecting hose; after the gas extraction is continued for a certain time, if the gas concentration in a certain gas extraction drill hole is found to be close to 0, and the gas concentration value of the adjacent drill hole is close to the concentration of the gas in the coal seam, judging that collapse occurs in the gas extraction drill hole; then the connection between the three-way pipe and the connecting hose is removed, a drilling peeping instrument is arranged in a gas extraction drilling hole, and the position where collapse occurs is detected and determined; then the four-way is respectively connected with a connecting hose, a water and slag removing device and a connecting flange, and a PE repair pipeline is placed into a gas extraction drilling hole through one end of the T-shaped tee joint and the other end of the four-way until reaching the collapse position; then, connecting the dredging drill bit with a dredging end drill rod, a connecting drill rod and a tail drill rod through a plurality of universal joints, and clamping the tail drill rod through a drill rod clamping device on the drilling machine;

S2: the isolation bag is connected with one end of the T-shaped tee joint and the outer ring of the tail bearing, and the other end of the T-shaped tee joint is connected with compressed air; then, starting the drilling machine and the compressed air, so that the explosion-proof motor drives the tail drill rod, the connecting drill rod, the dredging end drill rod and the dredging drill bit to rotate, and further cutting the coal body at the collapse position; the compressed air drives coal dust cut by the dredging drill bit to an annular space in the connecting hose and the PE repairing pipeline through flowing in the PE repairing pipeline until the coal dust enters a water and slag removing device connected with the lower end of the four-way under the action of gravity, and gas flowing out in the drilling process of the dredging drill bit flows into the upper end of the four-way through the annular space of the connecting hose and the PE repairing pipeline under the action of negative pressure of a pumping pipe network system, and then enters a gas pumping pipeline;

s3: stopping the drilling machine after the dredging drill bit drills a certain distance, closing compressed air, dismantling the connection between the PE repair pipeline and the T-shaped tee joint, pushing the PE repair pipeline to move towards the bottom of the gas extraction drilling hole, and if the movement is blocked, indicating that the coal body at the collapse position is not completely cut, and connecting the PE repair pipeline with the T-shaped tee joint at the moment; then the drilling machine is started again, so that the explosion-proof motor drives the tail drill rod, the connecting drill rod, the dredging end drill rod and the dredging drill bit to rotate, and further the coal body at the collapse position is cut again; when the PE repair pipeline is conveyed into the gas extraction drilling hole, the length of the PE repair pipeline entering the gas extraction drilling hole is similar to the length of the gas extraction drilling hole, and the collapse part of the gas extraction drilling hole is completely repaired; at the moment, the connection between the isolation bag and the tail bearing is removed, the connection between the drill rod clamping device and the tail drill rod is removed, and the drill rod, the dredging drill bit, the dredging end drill rod and the PE repairing pipeline which enter the gas extraction drill hole are withdrawn from the gas extraction drill hole;

The interconnecting guide pipeline is placed and gradually conveyed to a position needing to be interconnected in the gas extraction drilling hole, and then the sieve hole pipe is connected with the connecting pipe through threads and conveyed to the position needing to be interconnected in the gas extraction drilling hole; connecting the interconnection drill bit with the drill rod at the interconnection end part, connecting a plurality of connecting drill rods with the drill rod at the interconnection end part through universal joints, gradually conveying the interconnection drill bit to a position needing interconnection through the connection of the connecting drill rods and the universal joints, and drilling the interconnection drill bit along the direction of a certain inclination angle because the front end of the interconnection guide pipeline is provided with the inclination angle, so that the gas extraction drilling hole with collapse repair is interconnected with the adjacent drilling hole;

s5: the interconnecting guide pipeline has the same function as the PE repair pipeline in the collapse repair, and the connecting method is the same; during interconnection operation, the drilling machine is started to drive the tail drill rod, the connecting drill rod, the universal joint, the interconnection end drill rod and the interconnection drill bit to rotate by the explosion-proof motor, so that coal bodies between gas extraction drilling holes are cut and drilled; the cut coal scraps are moved into a water and slag removing device arranged at the hole opening of the gas extraction drill hole through the annular space of the sieve hole pipe and the interconnecting guide pipeline, and gas released by the coal body in the drilling process of the interconnecting drill bit enters the gas extraction pipeline at the upper end of the four-way pipe;

S6: along with continuous drilling of the interconnection drill bit, driving the screen hole pipe to enter the coal body, and after the interconnection drill bit drills to a preset position, starting a push-pull function of the drilling machine to enable the drill rod to move towards the direction of the drilling hole opening, so that the screen hole pipe stays in the interconnection drilling hole; repeating S4-S6 according to the actual engineering condition of the site, constructing 2-3 interconnected drilling holes, and interconnecting the collapsed gas extraction drilling holes and the adjacent 1-2 gas extraction drilling holes by the interconnected drilling holes to form a network of the gas extraction drilling holes; after the construction of the interconnected drilling is completed, the interconnected drill bit, the drill rod and the interconnected guide pipeline are withdrawn, the connecting hose is connected with the three-way pipe, the other two ends of the three-way pipe are respectively connected with the gas extraction pipeline and the water and slag removing device, and then the gas extraction is continuously implemented.

2. The integrated gas drainage borehole collapse repair and interconnection drainage method according to claim 1, wherein the method comprises the following steps: the step S1 specifically comprises the following steps:

s11: constructing a gas extraction drilling hole in a transportation gate way or a return air gate way of a coal mine underground stoping working face, and placing extraction pipes in the gas extraction drilling hole after the construction is finished; adopting a high polymer material or other hole sealing materials to seal the gas extraction drilling hole, wherein the depth and length of the hole sealing section from the roadway wall to the bottom of the drilling hole are more than 20 m; after the gas extraction drilling hole is plugged, connecting the connecting hose with the extraction pipe, so that the gas in the drilling hole enters the gas extraction pipe through the extraction pipe and the connecting hose; the gas extraction pipeline is finally connected with a gas extraction pump arranged on the ground, and negative pressure is provided by the gas extraction pump, so that gas flows in a pipe network formed by extraction pipelines laid underground in a coal mine; a sampling hole is formed in the surface of the connecting hose or the surface of the extraction pipe exposed outside the gas extraction drilling hole, and the sampling hole is used for providing a gas collection channel for a special instrument for measuring the concentration of gas extracted from the drilling hole;

S12: after the constructed gas extraction drill hole is integrated into a pipe network formed by gas extraction pipes under the coal mine, the gas extraction is started, and then the concentration of the gas flowing out of the drill hole is detected through a sampling hole every day; when the concentration of the gas in a certain gas extraction borehole approaches 0, and the concentration value of the gas in the adjacent borehole approaches to the concentration of the original gas in the coal bed, judging that collapse occurs in the gas extraction borehole;

s13: removing the connection between the three-way pipe and the connecting hose, placing the drilling peeping instrument in a gas extraction drilling hole, detecting and determining the position where collapse occurs, and recording the distance between the position and the hole opening of the gas extraction drilling hole; selecting PE repair pipelines with the lengths slightly higher than the value according to the distance; the opening of the PE repair pipeline is provided with a diameter-reducing section with a certain length; the four-way joint is respectively connected with a connecting hose, a water and slag removing device and a connecting flange, and sealing rubber rings are also padded on the outer surfaces of the connecting flange and the PE repair pipeline; placing the PE repair pipeline into a gas extraction drill hole through one end of a T-shaped tee joint and the other end of the four joint until the PE repair pipeline reaches a collapse position; the other end of the T-shaped tee joint is connected with compressed air, and an isolation bag is arranged at the inserted end of the PE repair pipeline; the isolation bag is tightly attached to the surface of a straight pipe of the T-shaped tee through iron wire rolling; the overall size of the isolation bag can adapt to displacement generated when the PE repair pipeline enters the gas extraction drill hole;

S14: connecting the dredging drill bit with a dredging end drill rod, a connecting drill rod and a tail drill rod through a plurality of universal joints, and clamping the tail drill rod through a drill rod clamping device on the drilling machine; the dredging drill bit is connected with the dredging end drill rod through threads; the dredging end drill rod and the connecting drill rod are also provided with bearings, and the inner rings of the bearings are fixed on the outer walls of the dredging end drill rod and the connecting drill rod; the bearing has the function that the rotary motion of the dredging end drill rod and the connecting drill rod drives the bearing inner ring to rotate, and the balls in the bearing are contacted with the bearing outer ring.

3. The integrated gas drainage borehole collapse repair and interconnection drainage method according to claim 1, wherein the method comprises the following steps: the step S2 specifically comprises the following steps:

s21: the outer ring of the tail bearing is provided with a groove, so that the isolation bag can be fixed and rolled tightly in the groove of the outer ring of the tail bearing through iron wires; the inner ring of the tail bearing is fixed on the outer wall of the tail drill rod, and the inner ring of the tail bearing rotates along with the tail drill rod in the process of rotating the tail drill rod; the isolation bag is connected with one end of the T-shaped tee joint and the outer ring of the tail bearing, and the other end of the T-shaped tee joint is connected with compressed air;

S22: starting the drilling machine and the compressed air, so that the explosion-proof motor drives the tail drill rod, the connecting drill rod, the dredging end drill rod and the dredging drill bit to rotate, and further cutting the coal body at the collapse position; the gas pressure of the compressed air is 0.5-0.7 MPa, the compressed air enters the PE repair pipeline through the T-shaped tee joint, and coal dust cut by the dredging drill bit is driven to an annular space in the connecting hose and the PE repair pipeline; dredging the annular space in the connecting hose and the PE repairing pipeline under the driving of the pressure difference of the coal dust cut by the drill bit until the coal dust enters a water and slag removing device connected with the lower end of the four-way joint under the action of gravity;

s23: in the process of dredging the drill bit drilling, gas accumulated due to blockage behind the collapse part flows to the orifice direction of the gas extraction drill hole due to the change of the tightness of the coal body at the collapse part, and the gas flows into the upper end of the four-way through the annular space of the connecting hose and the PE repair pipeline under the action of negative pressure of the extraction pipe network system and then enters the gas extraction pipeline.

4. The integrated gas drainage borehole collapse repair and interconnection drainage method according to claim 1, wherein the method comprises the following steps: the step S3 specifically comprises the following steps:

S31: when the dredging drill bit rotates to cut the coal body at the collapse position, the push-pull function of the drilling machine is synchronously started, so that the dredging drill bit can also move towards the direction of the bottom of the gas extraction drilling hole; stopping the drilling machine after the dredging drill bit drills a certain distance, closing compressed air, dismantling the connection of the PE repair pipeline and the T-shaped tee joint, pushing the PE repair pipeline to move towards the bottom of the gas extraction drilling hole, if the movement is blocked, indicating that the coal body at the collapse position is not completely chipped, connecting the PE repair pipeline with the T-shaped tee joint at the moment, continuously starting the drilling machine, enabling the explosion-proof motor to rotate so as to drive the dredging drill bit to rotate, and simultaneously starting the push-pull function of the drilling machine so that the dredging drill bit can also move towards the bottom of the gas extraction drilling hole;

s32: continuously repeating the step S31 until the length of the PE repair pipeline entering the gas extraction drilling hole is similar to the length of the gas extraction drilling hole when the PE repair pipeline is conveyed into the gas extraction drilling hole, and indicating that the collapse part of the gas extraction drilling hole is completely repaired; at the moment, the isolation bag is detached from being connected with the tail bearing, the drill rod clamping device is detached from being connected with the tail drill rod, and the drill rod entering the gas extraction drill hole, the dredging drill bit and the dredging end part drill rod are withdrawn from the gas extraction drill hole.

5. The integrated gas drainage borehole collapse repair and interconnection drainage method according to claim 1, wherein the method comprises the following steps: the step S4 specifically comprises the following steps:

s41: the method comprises the steps of placing and gradually conveying an interconnection guide pipeline to a position, needing interconnection, in a gas extraction drilling hole, wherein a certain inclination angle is formed in the front end of the interconnection guide pipeline, so that an interconnection drill bit enters a coal body along the direction of the inclination angle, and the gas extraction drilling hole with collapse repair is interconnected with an adjacent drilling hole; the interconnection guide pipeline is connected with the four-way joint and the T-shaped tee joint;

s42: connecting the interconnection drill bit with the interconnection end drill rod, connecting a plurality of drill rods with the interconnection end drill rod through universal joints, and simultaneously connecting the screen hole pipe with the connecting pipe through threads; gradually conveying the interconnected drill bits to the positions needing interconnection through the connection of the drill rods and the universal joints; 2 springs are arranged in the 180-degree direction in the connecting pipe, and when the connecting end drill rod carrying the interconnected drill bit is not combined with the connecting pipe, the 2 springs are in a stretching state, and a near quarter circular arc stop block on the movable limiting block is restrained in a circular arc groove formed in the inner wall of the connecting pipe; when the interconnected end drill rods with the interconnected drill bits are combined with the connecting pipes, the balls arranged in the grooves of the circumferential fixed stop blocks on the interconnected end drill rods are contacted with the inclined surfaces on the movable limiting blocks, so that the movable limiting blocks are pushed to move towards the depth direction of the holes, and the movable limiting blocks are fixed by the drag hooks; meanwhile, in the rotary drilling process of the interconnected drill bit and the interconnected end drill rod, as the balls are arranged in the grooves of the circumferential fixed stop blocks, the balls can roll in the grooves, so that the continuous running of the rotary drilling of the interconnected drill bit and the interconnected end drill rod is ensured.