Large-diameter anti-slip plugging and sealing casing, hole protection tooling and hole protection method for underground coal mines

Abstract

The present invention discloses a large-diameter anti-slip plugging and sealing casing, a hole protection tooling and a hole protection method for underground coal mines, including an anti-slip joint and a plugging casing. The anti-slip joint includes a first pipe body, and a plurality of rectangular grooves are evenly arranged on the side wall of the first pipe body in the circumferential direction. An anti-slip structure is arranged in each rectangular groove. In the present invention, the anti-slip joint and the plugging casing, as well as adjacent plugging casings, all adopt a plugging connection method, and are connected by the cooperation of a first annular buckle and an annular buckle groove. By setting screw holes on the female joint and external screws to cooperate, it solves the problem of low efficiency existing in the threaded connection type casing in the prior art. The anti-slip joint adopts a telescopic leg, and the expansion and contraction of the leg is controlled by controlling the water pressure. In large-angle upward holes, it can effectively prevent the plugging casing in the drill hole from slipping down, and solves the technical problem that the casing is easy to slip down in large-angle upward holes in the prior art.

Description

Technical Field

[0001] The invention belongs to the field of drilling equipment and relates to a sealing casing, in particular to a large-diameter anti-slip plug-in sealing casing, a hole protection tool and a hole protection method in an underground coal mine. Background Art

[0002] Large diameter drilling It is widely used in the fields of gas extraction in goafs, tunnel ventilation, emergency rescue, and underground pipeline laying. In the early stage of large-diameter drilling construction, it is necessary to insert casing into the borehole mouth to seal the hole, which is the basis for ensuring large displacement adjustment of the drilling trajectory, high-pressure water-containing bodies and gas control, and broken stratum protection. In the later stage of construction, in order to avoid the impact of local stratum collapse on the later use of the drilling, it is necessary to lower the drilling protection casing to a specific depth. The specifications and lowering depth of the casing should be determined in combination with the purpose of the project and geological conditions, and lowered in place according to the requirements of the drilling construction. At present, there are many specifications of large-diameter drilling hole mouth casing, and the length of a single piece is mostly 1 to 1.5m, and the weight of a single piece is greater than 25Kg. Most casings are threaded to ensure the integrity and connection strength of the casing.

[0003] In the prior art, the casing lowering and connection operation mainly adopts the manual screwing method. With the increase of the borehole diameter and the casing diameter, the casing stiffness and weight increase accordingly, resulting in many problems in the manual screwing and connection of the casing: first, due to the large diameter of the casing, the manual screwing and unscrewing operation is very inconvenient, the screwing is difficult, and the screwing speed is slow, resulting in low efficiency of the casing lowering operation; secondly, the casing mass continues to increase with the increase of the casing diameter, which invisibly increases the labor intensity of the casing screwing operation; especially when the large-diameter borehole with a high opening height is a large-angle upward hole, when lowering the casing of such a borehole, an operating platform needs to be built, and the casing in the borehole is tightened by the fall chain at the top of the drilling site and the sling, the purpose is to prevent the casing from slipping down and injuring people or slipping into the drill hole, but this method requires multiple workers to cooperate in the operation near the casing, and there are still certain safety hazards, and when adding casing, multiple workers need to climb to perform manual screwing and tightening manually, which not only increases the labor intensity, but also increases the safety risk. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a large-diameter anti-slip plug-in sealing casing, a hole protection tool and a hole protection method for underground coal mines, so as to solve the technical problems of low efficiency and easy slipping of the threaded connection casing in the prior art.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0006] On the one hand, the present invention discloses a large-diameter anti-slip plugging and sealing casing for underground coal mines, which includes an anti-slip joint and a plugging casing. The anti-slip joint includes a first pipe body. A plurality of rectangular grooves are evenly formed in the circumferential direction on the side wall of the first pipe body. An anti-slip structure is arranged in each rectangular groove. A ring groove is formed in the circumferential direction on the edge of the axial rear end face of the first pipe body. A pressing ring is arranged in the ring groove. A first cavity is formed between the axial rear end face of the ring groove and the axial front end face of the pressing ring. A female joint is arranged on the axial rear end of the first pipe body, and the outer diameter of the female joint is smaller than the inner diameter of the ring groove;

[0007] The anti-slip structure includes a leg seat, a leg fixedly arranged on the leg seat, and a spring seat coaxially arranged with the leg. A spring coaxially arranged with the leg is arranged on the spring seat. Convex platforms are arranged on both sides of the leg seat. A second cavity is formed between the convex platform and the inner wall of the rectangular groove where it is located;

[0008] Flow guiding grooves corresponding to the positions of each rectangular groove are arranged on the inner wall of the ring groove. Through holes communicating the first cavity and the second cavity are formed in the flow guiding grooves; A water injection hole is formed in the pressing ring, and the water injection hole is communicated with the first cavity. A water injection joint is installed in the water injection hole;

[0009] A cover plate groove coaxial with the rectangular groove is arranged around the edge of the opening of the rectangular groove. A cover plate is fixedly arranged on the cover plate groove. A through hole is formed in the cover plate, and the diameter of the through hole is larger than that of the leg and smaller than the cross-sectional diameter of the spring;

[0010] The plugging casing includes a second pipe body, a male joint and a female joint arranged at both ends of the second pipe body. The outer wall of the male joint is provided with a convex platform. A plurality of first annular buckles are evenly arranged on the outer wall of the male joint along the axial direction. Card slots are evenly arranged on the outer wall of the male joint along the circumferential direction. Stress dispersion holes are arranged at the ends of each card slot;

[0011] A plurality of annular buckle grooves corresponding to the first annular buckles on the outer wall of the male joint are arranged on the inner wall of the female joint. A screw hole is arranged in each annular buckle groove, and the screw holes and the card slots are arranged in a staggered manner;

[0012] The outer diameter of the first annular buckle is equal to the inner diameter of the annular buckle groove, and the outer diameter of the first annular buckle corresponds to the axial length of the annular buckle groove.

[0013] Furthermore, the above solution also includes the following technical features:

[0014] The water injection joint is connected to external static pressure water or a water pump.

[0015] A first sealing ring is respectively arranged between the press ring and the inner wall of the annular groove and the outer wall of the female joint.

[0016] The cover plate is fixedly arranged on the cover plate groove by screws.

[0017] A second sealing ring is arranged on the outer wall of the male joint.

[0018] The diameter of the stress dispersion hole is larger than the width of the clamping slot.

[0019] It further includes a hole protection tooling, which includes a pusher and a puller. The pusher includes a first connecting body, an external insertion body and a guiding body connected in sequence along the axis. The outer diameter of the guiding body is equal to the diameter of the first annular buckle on the male joint; the axial length of the guiding body is equal to that of the first annular buckle on the male joint;

[0020] The puller includes a second connecting body, an outer sealing body and a buckle section connected in sequence. A plurality of second annular buckles are uniformly arranged on the buckle section along the axis, and the size of the second annular buckle is the same as that of the first annular buckle.

[0021] Furthermore, the hole protection tooling of the large-diameter anti-slip plugging and sealing casing in coal mines also includes the following technical features:

[0022] Both the first connecting body and the second connecting body are threadedly connected to the drill pipe of the external drill rig.

[0023] A plurality of third sealing rings are arranged on the outer sealing body.

[0024] On the other hand, the present invention also discloses a hole protection method for a large-diameter anti-slip plugging and sealing casing in coal mines, which includes a method for lowering the plugging casing and a method for pulling out the plugging casing, and specifically includes the following steps:

[0025] The method for lowering the plugging casing includes the following steps:

[0026] Step 1, connect the anti-slip joint with the first plugging casing at the hole opening of the drill hole, and connect a hose of static pressure water or a water pump to the water injection joint of the anti-slip joint;

[0027] Step 2, place the connected anti-slip joint and the first plugging casing into the drill hole, and ensure that the female joint of the first plugging casing is exposed 30-50 cm;

[0028] Step 3, turn on the static pressure water or the water pump, and the water flow enters the first cavity of the anti-slip joint along the hose, and flows to the second cavity through the flow-through hole, thereby pushing the support legs to extend and support on the hole wall;

[0029] Step 4: Insert the male connector of the second insertion sleeve into the female connector of the first insertion sleeve, so that the first annular buckle on the second insertion sleeve is completely snapped into the annular buckle groove of the first insertion sleeve, and install screws of the corresponding specification into the screw holes on the female connector of the first insertion sleeve;

[0030] Step 5: Install the first connecting body of the pusher on the front end of the drill pipe of the drill rig, and insert the guiding body and the outer insertion body of the pusher into the female connector of the second insertion sleeve through the drill pipe respectively;

[0031] Step 6: Release the pressure of the water flow in the hose. The supporting legs move radially inward under the action of the spring and are retracted into the rectangular groove. Use the drill rig to push the drill pipe to drive the pusher to push the second insertion sleeve into the drill hole, so that the female connector of the second insertion sleeve is exposed by 30 - 50 cm. Execute Step 3 to extend the supporting legs of the anti-slip joint and fix the connected insertion sleeves in the drill hole on the hole wall;

[0032] Step 7: Withdraw the drill pipe and the pusher, leaving enough distance for the third insertion sleeve to be lowered at the front end of the pusher; repeat Steps 4 to 6 to successively lower the remaining insertion sleeves one by one;

[0033] The method for pulling out the insertion sleeve specifically includes the following steps:

[0034] Step 1: First, execute Step 3 in the sleeve lowering method to extend the supporting legs of the anti-slip joint, and install the second connecting body of the puller on the front end of the drill pipe of the drill rig;

[0035] Step 2: Push the puller to the drill hole orifice through the drill pipe and connect it with the insertion sleeve to be pulled out, so that the second annular buckle of the puller is snapped into the annular buckle groove of the female connector of the insertion sleeve to be pulled out;

[0036] Step 3: Release the pressure of the water flow in the hose. The supporting legs are retracted into the rectangular groove under the action of the spring. Use the drill rig to withdraw the drill pipe to drive the puller to completely pull out the outermost insertion sleeve from the drill hole, and ensure that the female connector of the second outermost insertion sleeve is exposed by 30 - 50 cm;

[0037] Step 4: Execute Step 3 in the sleeve lowering method to extend the supporting legs of the anti-slip joint and support them on the hole wall;

[0038] Step 5: Screw in the screws into the screw holes on the female connector of the second outermost insertion sleeve, so that the first annular buckle on the male connector of the outermost insertion sleeve disengages from the annular buckle groove in the female connector of the second outermost insertion sleeve. Lift the drill pipe, and pull out the male connector of the outermost insertion sleeve from the female connector of the second outermost insertion sleeve through the puller;

[0039] Step 6: Screw a screw into the screw hole on the female connector of the outermost inserted sleeve, so that the second annular buckle on the extractor disengages from the annular buckle groove in the female connector of the outermost inserted sleeve, and remove the outermost inserted sleeve.

[0040] Step 7: Repeat the above Steps 2 to 6 to sequentially pull out the inserted sleeves to be extracted in the drill hole and disassemble them one by one.

[0041] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0042] (Ⅰ) In the present invention, the anti-slip joint and the inserted sleeve, as well as between adjacent inserted sleeves, all adopt an inserted connection method. They are connected by the cooperation of the first annular buckle and the annular buckle groove. The structure is simple, the performance is reliable, and it is convenient and fast to use. It can effectively reduce the screwing operation intensity during the connection process of the inserted sleeve. By setting the screw hole on the female connector and the external screw in cooperation, the disassembly operation between the anti-slip joint and the inserted sleeve, as well as between adjacent inserted sleeves, is simple. It overcomes the disassembly problem caused by the lack of clamping conditions for the large-diameter sleeve with threaded connection, improves the efficiency of the lowering and extraction of the inserted sleeve, and solves the problem of low efficiency existing in the threaded connection type sleeve in the prior art.

[0043] (Ⅱ) The anti-slip joint in the present invention adopts telescopic legs, and the expansion and contraction of the legs are controlled by controlling the water pressure. In the large-angle upward hole, it can effectively prevent the inserted sleeve in the drill hole from slipping down, ensuring the safety during the connection and lowering process of the inserted sleeve, and solving the technical problem that the sleeve is easy to slip down in the large-angle upward hole in the prior art.

[0044] (Ⅲ) The pusher and extractor of the present invention can be used in conjunction with various existing coal mine underground drills or special sleeve lowering tools to perform the sleeve lowering operation, and can meet the requirements of the inserted sleeve hole protection construction for different types of drill holes. Description of the Drawings

[0045] Figure 1 It is a schematic diagram of the overall structure of the large-diameter anti-slip inserted and sealed sleeve for coal mine underground;

[0046] Figure 2 For Figure 1 It is a schematic diagram of the structure of the anti-slip joint in

[0047] Figure 3 For Figure 2 It is a schematic diagram of the structure of the first pipe body in

[0048] Figure 4 It is a front view schematic diagram of the anti-slip joint;

[0049] Figure 5 For Figure 4 It is a sectional view taken along the line A-A in

[0050] Figure 6 is Figure 2 a structural schematic diagram of the anti-rolling structure in

[0051] Figure 7 is Figure 1 a structural schematic diagram of the plug-in sleeve in

[0052] Figure 8 is Figure 7 a structural schematic diagram of the male connector in the plug-in sleeve in

[0053] Figure 9 is Figure 8 the B-B sectional view schematic diagram in

[0054] Figure 10 is Figure 7 a structural schematic diagram of the female connector in the plug-in sleeve in

[0055] Figure 11 is Figure 10 the C-C sectional view schematic diagram in

[0056] Figure 12 a structural schematic diagram of the pusher;

[0057] Figure 13 a structural schematic diagram of the extractor.

[0058] The meanings of the various labels in the figure are as follows: 1 - anti-rolling joint, 2 - plug-in sleeve, 3 - pusher, 4 - extractor;

[0059] 101 - first pipe body, 102 - anti-rolling structure, 103 - pressing ring, 104 - first cavity, 105 - second cavity, 106 - water injection hole, 107 - water injection joint, 108 - cover plate, 109 - first sealing ring, 1010 - second sealing ring;

[0060] 10101 - rectangular groove, 10102 - annular groove, 10103 - diversion groove, 10104 - flow-through hole, 10105 - cover plate groove;

[0061] 10201 - leg seat, 10202 - leg, 10203 - spring seat, 10204 - spring, 10205 - boss;

[0062] 201 second pipe body, 202 male connector, 203 female connector;

[0063] 20201 - first annular buckle, 20202 - slot, 20203 - stress dispersion hole;

[0064] 20301 - annular buckle groove, 20302 - screw hole, 20303 - screw;

[0065] 301 - First connecting body, 302 - External plug-in body, 303 - Guide body;

[0066] 401 - Second connecting body, 402 - External sealing body, 403 - Buckle section, 404 - Second annular buckle, 405 - Third sealing ring.

[0067] The specific content of the present invention will be further explained in detail below in conjunction with embodiments. Specific embodiments

[0068] It should be noted that all the components in the present invention, without special instructions, are components known in the art.

[0069] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent transformations made on the basis of the technical solutions of this application fall within the protection scope of the present invention.

[0070] The present invention provides a large-diameter anti-slip plugging and sealing casing for coal mines underground, as Figures 1 to 11 shown, including an anti-slip joint 1 and a plugging casing 2. The anti-slip joint 1 includes a first pipe body 101. A plurality of rectangular grooves 10101 are evenly arranged along the circumferential direction on the side wall of the first pipe body 101. An anti-slip structure 102 is arranged in each rectangular groove 10101. A ring groove 10102 is circumferentially arranged at the edge of the axial rear end face of the first pipe body 101. A pressing ring 103 is arranged in the ring groove 10102. A first cavity 104 is formed between the axial rear end face of the ring groove 10102 and the axial front end face of the pressing ring 103. A female joint is arranged at the axial rear end of the first pipe body 101, and the outer diameter of the female joint is smaller than the inner diameter of the ring groove 10102;

[0071] The anti-slip structure 102 includes a leg seat 10201, a leg 10202 fixedly arranged on the leg seat 10201, and a spring seat 10203 coaxially arranged with the leg 10202. A spring 10204 coaxially arranged with the leg 10202 is arranged on the spring seat 10203. Convex platforms 10205 are arranged on both sides of the leg seat 10201. A second cavity 105 is formed between the convex platforms 10205 and the inner wall of the rectangular groove 10101 where they are located;

[0072] Flow guiding grooves 10103 corresponding to the positions of each rectangular groove 10101 are arranged on the inner wall of the ring groove 10102. Flow holes 10104 communicating the first cavity 104 and the second cavity 105 are opened in the flow guiding grooves 10103; A water injection hole 106 is opened on the pressing ring 103, and the water injection hole communicates with the first cavity 104. A water injection joint 107 is installed in the water injection hole 106;

[0073] The opening of the rectangular groove 10101 is provided with a cover plate groove 10105 coaxial with the rectangular groove 10101 around its edge for one week. A cover plate 108 is fixedly arranged on the cover plate groove 10105. A through hole is opened on the cover plate 108, and the diameter of the through hole is larger than that of the leg 10202 and smaller than the cross-sectional diameter of the spring 10204.

[0074] The plug-in sleeve 2 includes a second pipe body 201, a male joint 202 and a female joint 203 arranged at both ends of the second pipe body 201. The outer wall of the male joint 201 is provided with a convex platform. A plurality of first annular buckles 20201 are uniformly arranged on the outer wall of the male joint 202 along the axial direction; a plurality of card slots 20202 are uniformly arranged on the outer wall of the male joint 202 along the circumferential direction, and a stress dispersion hole 20203 is arranged at the end of each card slot 20202.

[0075] A plurality of annular buckle grooves 20301 corresponding to the first annular buckles 20201 on the outer wall of the male joint 202 are arranged on the inner wall of the female joint 203, and a screw hole 20302 is arranged in each annular buckle groove 20301. The screw hole 20302 and the card slot 20202 are arranged staggeredly.

[0076] The outer diameter of the first annular buckle 20201 is equal to the inner diameter of the annular buckle groove 20301, and the outer diameter of the first annular buckle 20201 corresponds to the axial length of the annular buckle groove 20301.

[0077] In the above technical solution, a plurality of card slots 20202 are uniformly distributed on the male joint 202 along the circumferential direction. When the screw 20302 enters the female joint 203 through the screw hole 20303, due to the extrusion of the screw 20303, the male joint 202 is subjected to a radially inward pressure from the outside to the inside, and each branch of the male joint 202 is compressed inward together, so that the first annular buckle 20201 can be disengaged from the annular buckle groove 20301.

[0078] The boss 10205 on the leg seat 10201 is not fixed in the rectangular groove. When the external high-pressure water flow enters the second cavity 105 from the first cavity 104 through the flow hole 10104, under the action of the water pressure, the leg seat 10201 moves radially outward, so that the leg 10202 extends out of the through hole of the cover plate 108 and supports on the hole wall. At this time, the spring 10204 is compressed; when the external high-pressure water flow is depressurized, under the action of the spring 10204, the leg seat 10201 moves radially inward, and then drives the leg 10201 to retract into the inside of the cover plate 108.

[0079] The anti-slip joint 1 and the insertion sleeve 2, as well as adjacent insertion sleeves 2, all adopt an insertion connection method. They are connected by the cooperation of the first annular buckle 20201 and the annular buckle groove 20301. The structure is simple, the performance is reliable, and it is convenient and fast to use. It can effectively reduce the screwing operation intensity during the connection of the insertion sleeve 2. By setting the screw hole 20302 on the female joint 203 and the external screw 20303 to cooperate, the disassembly between the anti-slip joint 1 and the insertion sleeve 2, as well as between adjacent insertion sleeves 2, is simple. It overcomes the disassembly problem caused by the lack of clamping conditions for large-diameter sleeves with threaded connections, improves the efficiency of lowering and pulling out the insertion sleeve 2, and solves the technical problem of low efficiency existing in the threaded connection type sleeves in the prior art.

[0080] In addition, the anti-slip joint 1 adopts a telescopic leg 10202. By controlling the water pressure, the telescopic movement of the leg 10202 is controlled. In large-angle upward holes, it can effectively prevent the insertion sleeve 2 in the drill hole from slipping down, ensuring the safety during the connection and lowering of the insertion sleeve 2, and solving the technical problem of easy slipping of the sleeve in large-angle upward holes in the prior art.

[0081] Specifically, the water injection joint 107 is connected to the external static water or water pump, ensuring that the leg can extend out of the cover plate and support on the hole wall.

[0082] Specifically, first sealing rings 109 are respectively arranged between the inner wall of the pressure ring 103 and the ring groove 10102, and the outer wall of the female joint, ensuring the sealing performance of the first cavity.

[0083] Specifically, the cover plate 108 is fixedly arranged on the cover plate groove 10105 by screws, which is simple and convenient.

[0084] Specifically, a second sealing ring 1010 is arranged on the outer wall of the male joint 202. Adding the second sealing ring 1010 ensures the sealing performance of the connection part of the insertion sleeve, and further ensures the effect of pressure grouting for fixing the pipe when needed.

[0085] Specifically, the diameter of the stress dispersion hole 20203 is larger than the width of the clamping slot 20202. The stress dispersion hole is used to eliminate the stress concentration of the clamping slot.

[0086] It also includes a hole protection tooling, as Figures 12 to 13 shown, including a pusher 3 and a puller 4. The pusher 3 includes a first connecting body 301, an external insertion body 302, and a guiding body 303 that are connected in sequence along the axial direction. The outer diameter of the guiding body 303 is equal to the diameter of the first annular buckle 20201 on the male joint 202; the axial length of the guiding body 303 is equal to that of the first annular buckle 20201 on the male joint 202;

[0087] The extractor 4 includes a second connector 401, an outer seal 402, and a snap section 403 that are connected in sequence. A plurality of second annular snaps 404 are uniformly arranged along the axial direction on the snap section 403, and the size of the second annular snap 404 is the same as that of the first annular snap 20201.

[0088] In the above technical solution, the pusher and the extractor can be used in conjunction with various existing drills or special casing lowering tools in underground coal mines to implement the casing lowering operation, and can meet the plugging casing hole protection construction requirements of different types of drill holes.

[0089] Specifically, the first connector 301 and the second connector 401 are both threadedly connected to the drill pipe of the external drill, and the operation is simple.

[0090] Specifically, a plurality of third sealing rings 405 are arranged on the outer seal 402, which ensures the seal between the pusher and the female joint.

[0091] The present invention provides a method for protecting holes of large-diameter anti-slip plugging and sealing casings in underground coal mines, including a method for lowering plugging casings and a method for extracting plugging casings, specifically including the following steps:

[0092] The method for lowering plugging casings includes the following steps:

[0093] Step 1: Connect the anti-slip joint 1 with the first plugging casing 2 at the borehole orifice, and connect a hose of static water or a water pump to the water injection joint 107 of the anti-slip joint 1;

[0094] Step 2: Place the connected anti-slip joint 1 and the first plugging casing 2 into the borehole, and ensure that the female joint 203 of the first plugging casing 2 is exposed by 30 - 50 cm;

[0095] Step 3: Open the static water or the water pump, and the water flow enters the first cavity 104 of the anti-slip joint 1 along the hose, and flows through the flow hole 10104 to the second cavity 105, thereby pushing the leg 10202 to extend and support on the hole wall;

[0096] Step 4: Insert the male joint 202 of the second plugging casing 2 into the female joint 203 of the first plugging casing 2, so that the first annular snap 20201 on the second plugging casing 2 is completely snapped into the annular snap groove 20301 of the first plugging casing 2, and install screws 20303 of the corresponding specification into the screw holes 20302 on the female joint 203 of the first plugging casing 2;

[0097] Step 5: Install the first connector 301 of the pusher 3 at the front end of the drill pipe of the drill, and insert the guide body 303 and the outer plugging body 302 of the pusher 3 into the female joint 203 of the second plugging casing 2 respectively through the drill pipe;

[0098] Step 6: Release the pressure of the water flow in the hose. The support leg 10201 moves radially inward under the action of the spring 10204 and retracts into the rectangular groove 10101. Use the drill rig to push the drill pipe to drive the pusher 3 to push the second socket sleeve 2 into the borehole, so that the female joint 203 of the second socket sleeve 2 is exposed by 30 - 50 cm. Execute Step 3 to extend the support leg 10202 of the anti-slip joint 2 and fix the connected socket sleeve 2 in the borehole on the hole wall;

[0099] Step 7: Withdraw the drill pipe and the pusher 3 so that enough distance is left for the third socket sleeve 2 to be lowered at the front end of the pusher 3; Repeat Steps 4 to 6 and successively lower the remaining socket sleeves 2 one by one;

[0100] The method for pulling out the socket sleeve specifically includes the following steps:

[0101] Step 1: First, execute Step 3 in the method for lowering the casing to extend the support leg 10202 of the anti-slip joint 1, and install the second connecting body 401 of the puller 4 at the front end of the drill pipe of the drill rig;

[0102] Step 2: Push the puller 4 to the borehole orifice through the drill pipe and connect it to the socket sleeve 2 to be pulled out, so that the second annular buckle 404 of the puller 4 is snapped into the annular buckle groove 20301 of the female joint 203 of the socket sleeve 2 to be pulled out;

[0103] Step 3: Release the pressure of the water flow in the hose. The support leg 10202 retracts into the rectangular groove 10101 under the action of the spring 10204. Use the drill rig to withdraw the drill pipe to drive the puller 4 to completely pull out the outermost socket sleeve 2 from the borehole, and ensure that the female joint 203 of the second outermost socket sleeve 2 is exposed by 30 - 50 cm;

[0104] Step 4: Execute Step 3 in the method for lowering the casing to extend the support leg 10202 of the anti-slip joint 1 and support it on the hole wall;

[0105] Step 5: Screw the screw 20303 into the screw hole 20302 in the female joint 203 of the second outermost socket sleeve 2, so that the first annular buckle 20201 on the male joint 202 of the outermost socket sleeve 2 disengages from the annular buckle groove 20301 in the female joint 203 of the second outermost socket sleeve 2. Withdraw the drill pipe, and use the puller 4 to pull out the male joint 202 of the outermost socket sleeve 2 from the female joint 203 of the second outermost socket sleeve 2;

[0106] Step 6: Screw the screw 20303 into the screw hole 20302 in the female joint 203 of the outermost socket sleeve 2, so that the second annular buckle 404 on the puller 4 disengages from the annular buckle groove 20301 in the female joint 203 of the outermost socket sleeve 2, and remove the outermost socket sleeve 2;

[0107] Step 7: Repeat the above Steps 2 to 6 to successively pull out the plug sleeves 2 to be pulled out in the drill holes from the drill holes and disassemble them one by one.

Claims

1. A large-diameter anti-slip plugging and sealing casing for underground coal mines, comprising an anti-slip joint (1) and a plugging casing (2), characterized in that, The anti-slip joint (1) described above includes a first pipe body (101). A plurality of rectangular grooves (10101) are evenly formed in the circumferential direction on the side wall of the first pipe body (101). An anti-slip structure (102) is arranged in each rectangular groove (10101). A ring groove (10102) is formed in the circumferential direction at the edge of the axial rear end face of the first pipe body (101). A pressing ring (103) is arranged in the ring groove (10102). A first cavity (104) is formed between the axial rear end face of the ring groove (10102) and the axial front end face of the pressing ring (103). A female joint is arranged at the axial rear end of the first pipe body (101), and the outer diameter of the female joint is smaller than the inner diameter of the ring groove (10102). The anti-slip structure (102) includes a leg seat (10201), a leg (10202) fixedly arranged on the leg seat (10201), and a spring seat (10203) coaxially arranged with the leg (10202). A spring (10204) coaxial with the leg (10202) is arranged on the spring seat (10203). Convex platforms (10205) are arranged on both sides of the leg seat (10201). A second cavity (105) is formed between the convex platforms (10205) and the inner wall of the rectangular groove (10101) where they are located. Flow guiding grooves (10103) corresponding to the positions of each rectangular groove (10101) are arranged on the inner wall of the ring groove (10102). Flow through holes (10104) communicating the first cavity (104) and the second cavity (105) are formed in the flow guiding grooves (10103). A water injection hole (106) is formed in the pressing ring (103), and the water injection hole communicates with the first cavity (104). A water injection joint (107) is installed in the water injection hole (106). A cover plate groove (10105) coaxial with the rectangular groove (10101) is arranged around the edge of the opening of the rectangular groove (10101). A cover plate (108) is fixedly arranged on the cover plate groove (10105). A through hole is formed in the cover plate (108), and the diameter of the through hole is larger than that of the leg (10202) and smaller than the cross-sectional diameter of the spring (10204). The plug-in sleeve (2) includes a second pipe body (201), a male joint (202) and a female joint (203) arranged at both ends of the second pipe body (201). A plurality of first annular buckles (20201) are evenly arranged on the outer wall of the male joint (202) along the axial direction. The diameter of the first annular buckle (20201) is smaller than the outer diameter of the second pipe body (201). A plurality of clamping slots (20202) are evenly arranged on the outer wall of the male joint (202) along the circumferential direction. Stress dispersion holes (20203) are arranged at the ends of each clamping slot (20202). A plurality of annular snap grooves (20301) corresponding to the first annular snaps (20201) on the outer wall of the male joint (202) are provided on the inner wall of the female joint (203). A screw hole (20302) is provided in each of the annular snap grooves (20301), and the screw holes (20302) are arranged staggeredly with respect to the slot (20202). The outer diameter of the first annular snap (20201) is equal to the inner diameter of the annular snap groove (20301), and the outer diameter of the first annular snap (20201) is correspondingly equal to the axial length of the annular snap groove (20301).

2. The large-diameter anti-slip plugging and sealing casing for underground coal mines according to claim 1, characterized in that The water injection joint (107) is connected to external static pressure water or a water pump.

3. The large-diameter anti-slip plugging and sealing casing for underground coal mines according to claim 1, wherein First sealing rings (109) are respectively provided between the pressing ring (103) and the inner wall of the annular groove (10102) and the outer wall of the female joint.

4. The large-diameter anti-slip plugging and sealing casing for underground coal mines according to claim 1, characterized in that The cover plate (108) is fixedly arranged on the cover plate groove (10105) by screws.

5. The large-diameter anti-slip plugging and sealing casing for underground coal mines according to claim 1, characterized in that, A second sealing ring (1010) is provided on the outer wall of the male joint (202).

6. The large-diameter anti-slip plugging and sealing casing for underground coal mines according to claim 1, characterized in that, The diameter of the stress dispersion hole (20203) is larger than the width of the slot (20202).

7. The large-diameter anti-slip plugging and sealing casing for underground coal mines according to claim 1, characterized in that, It further includes a hole protection tooling, which includes a pusher (3) and a puller (4). The pusher (3) includes a first connecting body (301), an external insertion body (302), and a guiding body (303) that are connected in sequence along the axial direction. The outer diameter of the guiding body (303) is equal to the diameter of the first annular snap (20201) on the male joint (202); the axial length of the guiding body (303) is equal to that of the first annular snap (20201) on the male joint (202). The puller (4) includes a second connecting body (401), an external sealing body (402), and a snap section (403) that are connected in sequence. A plurality of second annular snaps (404) are uniformly arranged along the axial direction on the snap section (403), and the sizes of the second annular snaps (404) are the same as those of the first annular snaps (20201).

8. The large-diameter anti-slip plugging and sealing casing for underground coal mines according to claim 7, characterized in that, Both the first connecting body (301) and the second connecting body (401) are threadedly connected to the drill pipe of an external drilling rig.

9. The large-diameter anti-slip plugging and sealing casing for underground coal mines according to claim 7, characterized in that, A plurality of third sealing rings (405) are provided on the external sealing body (402).

10. A method for protecting boreholes of a large-diameter anti-slip plugging and sealing casing underground in a coal mine according to any one of claims 7 to 9, characterized in that, It includes a method for lowering the inserted casing and a method for pulling out the inserted casing, specifically including the following steps: The method for lowering the inserted casing includes the following steps: Step 1, connect the anti-slip joint (1) to the first inserted casing (2) at the drilling hole opening, and connect a hose of static pressure water or a water pump to the water injection joint (107) of the anti-slip joint (1). Step 2, place the connected anti-slip joint (1) and the first inserted casing (2) into the drilling hole, and ensure that the female joint (203) of the first inserted casing (2) is exposed by 30 - 50 cm. Step 3, turn on the static pressure water or the water pump, and the water flows along the hose into the first cavity (104) of the anti-slip joint (1), and flows to the second cavity (105) through the flow hole (10104), thereby pushing the legs (10202) to extend and support on the hole wall. Step 4: Insert the male connector (202) of the second insertion sleeve (2) into the female connector (203) of the first insertion sleeve (2), so that the first annular snap (20201) on the second insertion sleeve (2) is completely snapped into the annular snap groove (20301) of the first insertion sleeve (2), and install screws (20303) of corresponding specifications into the screw holes (20302) on the female connector (203) of the first insertion sleeve (2). Step 5: Install the first connecting body (301) of the pusher (3) at the front end of the drill pipe of the drill rig, and insert the guiding body (303) and the outer insertion body (302) of the pusher (3) into the female connector (203) of the second insertion sleeve (2) respectively through the drill pipe. Step 6: Release the water pressure in the hose. The legs (10201) move radially inward under the action of the spring (10204) and are retracted into the rectangular groove (10101). Use the drill rig to push the drill pipe to drive the pusher (3) to push the second insertion sleeve (2) into the drill hole, so that the female connector (203) of the second insertion sleeve (2) is exposed 30 - 50 cm. Execute Step 3 to extend the legs (10202) of the anti-slip joint (2) and fix the connected insertion sleeve (2) in the drill hole on the hole wall. Step 7: Withdraw the drill pipe and the pusher (3) to leave enough distance for the third insertion sleeve (2) to be lowered at the front end of the pusher (3); repeat Steps 4 to 6 to successively lower the remaining insertion sleeves (2) one by one. The method for pulling out the insertion sleeve specifically includes the following steps: Step 1: First, execute Step 3 in the method for lowering the sleeve to extend the legs (10202) of the anti-slip joint (1), and install the second connecting body (401) of the puller (4) at the front end of the drill pipe of the drill rig. Step 2: Push the puller (4) to the drill hole orifice through the drill pipe and connect it with the insertion sleeve (2) to be pulled out, so that the second annular snap (404) of the puller (4) is snapped into the annular snap groove (20301) of the female connector (203) of the insertion sleeve (2) to be pulled out. Step 3: Release the water pressure in the hose. The legs (10202) are retracted into the rectangular groove (10101) under the action of the spring (10204). Use the drill rig to withdraw the drill pipe to drive the puller (4) to completely pull out the outermost insertion sleeve (2) from the drill hole, and ensure that the female connector (203) of the second outermost insertion sleeve (2) is exposed 30 - 50 cm. Step 4: Execute Step 3 in the method for lowering the sleeve to extend the legs (10202) of the anti-slip joint (1) and support them on the hole wall. Step 5: Screw the screw (20303) into the screw hole (20302) on the female connector (203) of the second outermost insertion sleeve (2) to disengage the first annular snap (20201) on the male connector (202) of the outermost insertion sleeve (2) from the annular snap groove (20301) in the female connector (203) of the second outermost insertion sleeve (2), withdraw the drill pipe, and pull out the male connector (202) of the outermost insertion sleeve (2) from the female connector (203) of the second outermost insertion sleeve (2) through the puller (4). Step 6, screw a screw (20303) into the screw hole (20302) on the female joint (203) of the outermost plugging sleeve (2), so that the second annular buckle (404) on the extractor (4) disengages from the annular buckle groove (20301) inside the female joint (203) of the outermost plugging sleeve (2), and remove the outermost plugging sleeve (2); Step 7, repeat the above steps 2 to 6, and sequentially pull out the plugging sleeves (2) to be extracted in the drill hole from the drill hole and disassemble them one by one.

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