Device and method for preventing horizontal section of directional long drill hole of bottom plate from being broken

Abstract

The invention relates to the technical field of geological mining, in particular to a bottom plate directional long drill hole horizontal section anti-fracture device and method.The bottom plate directional long drill hole horizontal section anti-fracture device comprises a plurality of drill rods which are sequentially combined and matched with directional drilling machine equipment to conduct horizontal section long drill hole construction between coal seam groups; the back-reaming drill bit is detachably arranged at the end part of the drill rod which is initially buried into soil; grouting pipe groups; and an anti-fracture assembly. In the variable-diameter reaming operation, the hole wall of the long drill hole formed in the drill hole between the coal seam groups can be firstly subjected to guniting consolidation, the metal sleeve is used for supporting the easy-to-break area, rock mass deformation around the hole wall of the long drill hole is resisted to a certain degree, and the problem that in the working face mining process, the hole wall of the long drill hole is prone to fracture is effectively solved. The problem that the local area of the horizontal section of the directional long drill hole below the middle area of the working face of the protective layer is subjected to dislocation deformation and even is directly broken due to the unbalanced deformation of the geological fracture zone and the bottom plate after the extraction dynamic stress is unloaded is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geological exploitation, in particular to a floor directional long borehole horizontal section breakage prevention device and method. BACKGROUND

[0002] The statements herein merely provide background technology related to the present application, and do not necessarily constitute prior art.

[0003] At present, under the occurrence conditions of close distance outburst coal seam group, in addition to the gas control of the coal seam during the mining of the protective layer, the mining period will also face the problem of overrun caused by the gas inflow of the adjacent layer. At present, the application effect of the directional long borehole interception technology for the extraction of the pressure relief gas in the protected layer under the protective layer has been good.

[0004] However, during the mining process of the working face, the uneven deformation of the floor after the geological fracture zone and the mining stress unloading leads to the dislocation deformation of the local area of the directional long borehole horizontal section under the middle area of the protective layer working face, and even directly breaks, thereby affecting the construction effect of the horizontal directional long borehole. SUMMARY

[0005] The purpose of the present application is to solve the above problems, and provide a floor directional long borehole horizontal section breakage prevention device and method.

[0006] To solve the above technical problems, the present application adopts the following technical scheme: a floor directional long borehole horizontal section breakage prevention device, comprising: A plurality of drill rods are sequentially combined and cooperate with the directional drilling rig equipment to perform long borehole construction in the horizontal section between the coal seam group, one end of the long borehole close to the directional drilling rig equipment is set as a soil entering point, and the other end of the long borehole is set as a soil exiting point; A reaming bit is detachably arranged at the end of the drill rod initially entering the soil, used for entering the reamer following the drill rod from the soil exiting point and performing variable-diameter reaming of the long borehole; An injection pipe group is detachably arranged at the end of the reaming bit away from the drill rod, used for grouting and consolidating the hole wall of the variable-diameter long borehole; A breakage prevention assembly is arranged outside the injection pipe group, used for entering the variable-diameter long borehole following the injection pipe group to support and reinforce the specified area.

[0007] Further, the injection pipe group comprises an inner pipe and an outer pipe coaxially sleeved from inside to outside, one end of the inner pipe close to the reaming bit is provided with a connector, the inside of the connector is hollow and communicates with the inner pipe, and the outer periphery of the connector is uniformly provided with two or more than two nozzles; When the inner tube rotates, the two or more nozzles uniformly distributed on the outer periphery of the joint spray the hole wall of the long drill hole.

[0008] Further, the end of the inner tube and the outer tube is provided with a transmission assembly a for driving the inner tube and the outer tube to rotate synchronously; The transmission assembly a includes an outer gear ring sleeved on the outer wall of the inner tube and close to one end of the joint, and an inner gear ring coaxially arranged on the inner wall of the outer tube, a tooth column is arranged between the outer gear ring and the inner gear ring, and the tooth column is adaptively connected in rotation on the end surface of the joint.

[0009] Further, the anti-breaking assembly includes a metal sleeve supported on the hole wall of the long drill hole, and a synchronous expansion mechanism matched on the metal sleeve and expanding the metal sleeve in diameter; The synchronous expansion mechanism includes a movable sliding sleeve slidingly arranged on the outer wall of the outer tube, a plurality of wedge-shaped groups a centrally and symmetrically arranged on the movable sliding sleeve, each wedge-shaped group a is composed of two or more first wedge-shaped blocks and uniformly distributed along the length direction of the movable sliding sleeve, a second wedge-shaped block is matched and arranged on the inclined surface of each first wedge-shaped block, a plurality of second wedge-shaped blocks arranged along the length direction of the movable sliding sleeve form a wedge-shaped group b, the outer end of the wedge-shaped group b is fixed with an arc plate, the number of the arc plate is the same as that of the wedge-shaped group a, and a plurality of arc plates are combined to form a "petal" structure, and the outer wall of each arc plate is in contact with the inner wall of the metal sleeve.

[0010] Further, a support ring a is slidingly arranged on the movable sliding sleeve and close to one end of the arc plate, a plurality of slide grooves are arranged on the support ring a, the number of the slide grooves is the same as that of the arc plate, a sliding block is arranged on the arc plate and limited to move along the radial direction of the movable sliding sleeve, and the sliding block is slidingly arranged in cooperation with the slide groove.

[0011] Further, the anti-breaking assembly further includes a transmission assembly b arranged on the outer tube and used for driving the movable sliding sleeve to move; The transmission assembly b includes a support ring b elongatedly arranged at the end of the movable sliding sleeve, and a fixed ring adjacently and intervally arranged on one side of the support ring b, a screw rod and a guide rod are respectively arranged on the two sides of the fixed ring, one end of the screw rod is connected with the support ring b in cooperation, and one end of the guide rod is slidingly and guidingly connected with the corresponding position of the support ring b.

[0012] Further, the outer end of the fixed ring is provided with a transmission assembly c; The transmission assembly c includes a gear one arranged on the outer wall of the outer tube, a gear two arranged on the outer wall of the screw and matched with the gear one, an outer ring coaxially arranged on the inner side of the end surface of the gear two, and an inner ring arranged on the inner side of the outer ring, the inner wall of the outer ring is uniformly provided with a plurality of wedge-shaped spaces, a spring is arranged in each wedge-shaped space along the tangent line of the inner ring, a roller is arranged on the end of the spring close to the inner ring, and the inner ring is fixed on the outer wall of the screw. When the outer tube rotates counterclockwise under the power of the directional drilling rig equipment, the gear two is driven to rotate clockwise through the matching of the gear one and the gear two, at this time, the roller is pushed to the narrow end of the wedge-shaped space under the action of friction and the spring, the outer ring and the inner ring are locked, and the screw passing through the inner ring is driven to rotate synchronously. When the outer tube rotates clockwise, the outer ring will rotate counterclockwise with the gear two, so that the roller is pushed to the wide end of the wedge-shaped space, the locking between the outer ring and the inner ring is released, the outer ring idles, and the inner ring does not follow.

[0013] Further, the part of the screw between the support ring a and the support ring b is provided with a telescopic cover which is telescopic and foldable, and the support ring b is provided with a cleaning column block corresponding to the end surface of the support ring a and located at the position where the guide rod passes and slides, the cleaning column block is used for scraping off the sand and rock debris attached to the surface of the guide rod.

[0014] Further, each structure outside the transmission assembly c is covered with a dustproof shell.

[0015] The anti-breaking method is used for the anti-breaking device of the floor directional long borehole horizontal section, and specifically includes the following steps: S1, analyze the lithological characteristics of the coal seam group, establish a numerical model, determine the reasonable arrangement horizon and the easy breaking area of the directional long borehole based on the deformation and pressure relief and permeability enhancement characteristics of the directional long borehole at different positions between the coal seam group; S2, position the directional drilling rig equipment, and cooperate with multiple drill rods to perform directional long borehole construction on the target area; S3, disassemble and remove the drill bit on the corresponding drill rod at the unearthed point position, replace the back-reaming drill bit and the injection pipe group, continue to use the directional drilling rig equipment, back-drill multiple sequentially combined drill rods from the unearthed point to the earth point, and expand the hole diameter of the long borehole through the back-reaming drill bit; S4, position the high-pressure grouting pump, use the inner tube, cooperate with the joint and the two or more than two nozzles uniformly distributed on the joint to uniformly grout and consolidate the hole wall of the long borehole during the rotation of the inner tube; S5, the broken area determined in step S1, in the process of moving the drill rod back to drill, the anti-breaking assembly outside the outer tube is moved to the target broken area, at this time, the drill rod is rotated in the opposite direction, the multiple arc plates outside the outer tube are expanded synchronously and uniformly, the metal sleeve is plastically deformed, and is tightly attached to the hole wall of the long borehole for support and reinforcement; S6, after the above operation is completed, the broken area position is broken and extracted, and the effect is recorded, so as to provide data support for the next stage of directional long borehole construction and improvement of the anti-breaking process.

[0016] The beneficial effects of the present application are as follows: The present application can first spray and consolidate the hole wall of the long borehole drilled in the coal seam group through the setting of the grouting pipe group and the anti-breaking assembly, and support the broken area with the metal sleeve, to a certain extent, resist the deformation of the rock mass around the hole wall of the long borehole, effectively solve the problem that the local area of the horizontal section of the directional long borehole under the middle area of the protective layer working face is dislocated and deformed, even directly broken, due to the uneven deformation of the floor after the geological fracture zone and the extraction of dynamic stress; and through the setting of the transmission assembly a, the transmission assembly b and the transmission assembly c, the long borehole can be drilled and expanded in cooperation with the directional drilling rig equipment, the spray and consolidation and the fixed-point release and expansion of the metal sleeve are carried out synchronously, and the effective support and reinforcement of the broken area of the hole wall of the long borehole are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a perspective view of the whole of an embodiment of the present application; Figure 2 It is a perspective view of the whole of an embodiment of the present application; Figure 3 It is a perspective view of the whole of an embodiment of the present application; Figure 4 It is a perspective view of the whole of an embodiment of the present application; Figure 5 It is a perspective view of the whole of an embodiment of the present application; Figure 6 It is a perspective view of the whole of an embodiment of the present application; Figure 7 It is a perspective view of the whole of an embodiment of the present application; Figure 8 It is a perspective view of the whole of an embodiment of the present application; Figure 9Figure 1 is an exploded perspective view of the joint and transmission assembly a according to an embodiment of the present application; Figure 10 Figure 2 is another exploded perspective view of the joint and transmission assembly a according to an embodiment of the present application.

[0018] In the figure: 1, drill rod; 2, back expansion drill bit; 3, anti-breaking assembly; 31, metal sleeve; 32, synchronous expansion mechanism; 321, movable sliding sleeve; 322, first wedge block; 323, second wedge block; 324, arc plate; 325, support ring a; 326, sliding groove; 327, sliding block; 33, support ring b; 34, fixed ring; 35, screw rod; 36, guide rod; 37, gear one; 371, gear two; 372, outer ring; 373, inner ring; 374, wedge-shaped space; 375, spring; 376, roller; 4, inner tube; 41, joint; 42, nozzle; 5, outer tube; 6, outer tooth ring; 61, inner tooth ring; 62, tooth column; 7, telescopic cover; 8, cleaning column block; 9, dustproof shell. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The embodiments in the present application and the features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0020] Please refer to Figures 1-10 The present application discloses a floor directional long borehole horizontal section anti-breaking device, which is applied to the easy-breaking area of the directional long borehole and protects the easy-breaking area from breaking, and comprises: A plurality of drill rods 1 are sequentially combined and cooperated with the directional drilling rig equipment to perform long borehole construction of the horizontal section among the coal seams, one end of the long borehole close to the directional drilling rig equipment is set as a soil entering point, and the other end of the long borehole is set as a soil exiting point; A back expansion drill bit 2 is detachably arranged at the end of the drill rod 1 initially entering the soil, is used for entering the back drill following the drill rod 1 from the soil exiting point, and is used for performing variable-diameter reaming on the long borehole; A grouting pipe group is detachably arranged at the end of the back expansion drill bit 2 away from the drill rod 1, and is used for performing grouting consolidation on the hole wall of the variable-diameter long borehole; An anti-breaking assembly 3 is arranged outside the grouting pipe group, is used for entering the variable-diameter long borehole following the grouting pipe group, and is used for supporting and reinforcing the specified area.

[0021] In a specific implementation, a plurality of sequentially combined drill pipes 1 are used to build a directional horizontal long borehole in a coal seam group under the start of a directional drilling rig device, from the earth entry point position to the earth exit point position, then the drill bit on the drill pipe 1 at the earth exit point position is disassembled and removed, the back reaming bit 2 and the grouting pipe group are connected and locked in sequence using bolts, and the back reaming bit 2 is reamed and expanded under the start of the directional drilling rig device, wherein, in the back reaming and expanding process, the long borehole wall between the coal seams is first grouted and consolidated through the grouting pipe group, and the easy-to-break area is supported under the action of the anti-breaking assembly 3, to a certain extent, to resist the deformation of the rock mass around the long borehole wall, effectively solving the problem of local dislocation and deformation of the directional long borehole horizontal section under the middle area of the protective layer working face, even direct breaking, caused by the uneven deformation of the floor after the geological fracture zone and the extraction of dynamic stress.

[0022] It should be noted that the drill pipe 1 is provided with a detection head and an upper computer electrically connected to the detection head, and the detection head can project at least three reference marks to the borehole wall of the long borehole and collect borehole wall images while moving along the horizontally directional long borehole with the drill pipe 1, wherein the at least three reference marks form a reference surface, and at this time, the upper computer receives the borehole wall images sent by the detection head and extracts the reference surface contained in the borehole wall images to construct the borehole wall imaging of the directional long borehole according to the multiple frames of borehole wall images and the corresponding offset vectors, so that the actual position of the drill pipe 1 in the borehole wall of the long borehole can be monitored at any time.

[0023] In an embodiment, the grouting pipe group comprises an inner pipe 4 and an outer pipe 5 coaxially sleeved from inside to outside, an adapter 41 is arranged on one end of the inner pipe 4 close to the back reaming bit 2, the inside of the adapter 41 is communicated with the inner pipe 4, and two or more nozzles 42 are uniformly arranged on the outer periphery of the adapter 41. When the inner pipe 4 rotates, the two or more nozzles 42 uniformly distributed on the outer periphery of the adapter 41 will uniformly spray grout to the borehole wall of the variable-diameter long borehole. By assembling the inner pipe 4 and the outer pipe 5 in a coaxial sleeving manner, the inner pipe 4 will rotate relatively when the combined and fixed drill pipe 1, back reaming bit 2 and grouting pipe group are reamed under the start of the directional drilling rig device, at this time, the adapter 41 installed on one end of the inner pipe 4 close to the back reaming bit 2 and the two or more nozzles 42 uniformly slotted and installed on the outer periphery of the adapter 41 will uniformly spray grout to the borehole wall of the long borehole and consolidate it.

[0024] It should be noted that the cement slurry applied with the grouting pipe group is mixed with an aluminate accelerator (such as sodium aluminate) to accelerate the hydration of aluminate and quickly generate ettringite, thereby shortening the initial setting time to 3-5 minutes.

[0025] In an embodiment, the inner tube 4 and the outer tube 5 are provided with a transmission assembly a at one end of the joint 41 for driving the inner tube 4 and the outer tube 5 to rotate synchronously; The transmission assembly a comprises an outer gear ring 6 sleeved on the outer wall of the inner tube 4 and close to one end of the joint 41 and an inner gear ring 61 coaxially arranged on the inner wall of the outer tube 5, and a tooth column 62 is arranged between the outer gear ring 6 and the inner gear ring 61, and the tooth column 62 is adapted to be rotationally connected on the end surface of the joint 41. In this way, by sleeving the outer gear ring 6 on the outer wall of the inner tube 4 and welding the inner gear ring 61 on the inner wall of the outer tube 5, and by matching the meshing surface between the outer gear ring 6 and the inner gear ring 61 with the tooth column 62, when the inner tube 4 rotates following the drill pipe 1, the outer tube 5 will rotate relative to the inner tube 4 through the meshing of the outer gear ring 6, the tooth column 62 and the inner gear ring 61, achieving the effect of synchronous driving the rotation of the inner tube 4 and the outer tube 5 formed on the grouting pipe group.

[0026] In an embodiment, the anti-breaking assembly 3 comprises a metal sleeve 31 supported on the hole wall of the long drill hole, and a synchronous expansion mechanism 32 matched on the metal sleeve 31 and expanding the metal sleeve 31; The synchronous expansion mechanism 32 comprises a movable sliding sleeve 321 slidingly arranged on the outer wall of the outer tube 5, a plurality of wedge-shaped groups a centrally and symmetrically arranged on the movable sliding sleeve 321, each wedge-shaped group a being composed of two or more first wedge-shaped blocks 322 and uniformly distributed along the length direction of the movable sliding sleeve 321, each first wedge-shaped block 322 being provided with a second wedge-shaped block 323 matched on the inclined surface, a plurality of second wedge-shaped blocks 323 arranged along the length direction of the movable sliding sleeve 321 forming a wedge-shaped group b, and an arc plate 324 fixed on the outer end of the wedge-shaped group b, the number of the arc plates 324 being the same as that of the wedge-shaped groups a, and a plurality of the arc plates 324 being combined to form a "petal" structure, and the outer wall of each arc plate 324 being in contact with the inner wall of the metal sleeve 31. In this way, by slidingly connecting the movable sliding sleeve 321 on the outer wall of the outer tube 5 and screwing the plurality of wedge-shaped groups a composed of the first wedge-shaped blocks 322 on the movable sliding sleeve 321, when the movable sliding sleeve 321 moves horizontally under force, it will push the movable sliding sleeve 321 along the length direction of the outer tube 5, and by matching the inclined surfaces of the first wedge-shaped blocks 322 and the second wedge-shaped blocks 323, the wedge-shaped group b composed of the second wedge-shaped blocks 323 will move perpendicularly to the pushing direction of the movable sliding sleeve 321, driving the arc plate 324 fixed on the outer end of the wedge-shaped group b to move radially outward along the movable sliding sleeve 321, achieving the effect of the plurality of arc plates 324 similar to the "petal" unfolding, so that the metal sleeve 31 is expanded by plastic deformation to fit the hole wall, effectively supporting and reinforcing the hole wall of the long drill hole.

[0027] It should be noted that the metal sleeve 31 is made of high ductility metal (such as low carbon steel, stainless steel, titanium alloy) or composite material, and the outer surface is additionally coated with rubber coating (such as NBR, FKM) for enhanced sealing.

[0028] In an embodiment, a support ring a 325 is arranged on the movable sleeve 321 and relatively slides near one end of the arc plate 324, the support ring a 325 is provided with the same number of sliding grooves 326 as the arc plate 324, and the arc plate 324 is provided with a sliding block 327 that limits the movement in the radial direction of the movable sleeve 321, and the sliding block 327 is arranged in sliding cooperation with the sliding groove 326. In this way, by arranging the support ring a 325 that relatively slides on the movable sleeve 321, the uniformly distributed multiple sliding grooves 326 welded on the support ring a 325, and the sliding block 327 welded on the cross section of each arc plate 324, the relative sliding of the sliding groove 326 and the sliding block 327 can limit and support the linear movement of the arc plate 324 in the radial direction of the movable sleeve 321 during the "petal type" unfolding operation of the arc plate 324, effectively ensuring the expansion effect of the metal sleeve 31.

[0029] In an embodiment, the anti-breaking assembly 3 further comprises a transmission assembly b arranged on the outer pipe 5 and used to drive the movable sleeve 321 to move; The transmission assembly b comprises a support ring b 33 integrally arranged at the end of the movable sleeve 321, a fixed ring 34 arranged adjacent to and spaced apart from one side of the support ring b 33, a screw rod 35 and a guide rod 36 arranged on the two sides of the fixed ring 34 respectively, and a section of the screw rod 35 is connected with the support ring b 33 in cooperation, and a section of the guide rod 36 is connected with the corresponding position of the support ring b 33 in sliding guide. In this way, by arranging the support ring b 33 integrally formed at the end of the movable sleeve 321, and arranging the fixed ring 34 on the outer wall of the outer pipe 5 in a ring groove for limiting and supporting and adjacent to one side of the support ring b 33, applying force to drive the screw rod 35 installed on the fixed ring 34, and using the threaded connection between the screw rod 35 and the support ring b 33 to make the support ring b 33 and the movable sleeve 321 integrally formed at the other side of the guide rod 36 to move linearly along the length direction of the outer pipe 5, the torque is transmitted to cooperate with the wedge-shaped group a and the wedge-shaped group b to expand and support the metal sleeve 31.

[0030] In an embodiment, the outer end of the fixed ring 34 is provided with a transmission assembly c; The transmission assembly c includes a gear one 37 arranged on the outer wall of the outer tube 5, a gear two 371 connected with the gear one 37 and arranged outside the screw rod 35, and an outer ring 372 and an inner ring 373 coaxially arranged on the end surface of the gear two 371, wherein the inner wall of the outer ring 372 is uniformly provided with a plurality of wedge-shaped spaces 374, each of the wedge-shaped spaces 374 is provided with a spring 375 along the tangent of the inner ring 373, and the end of the spring 375 close to the inner ring 373 is provided with a roller 376, and the inner ring 373 is sleeved and fixed on the outer wall of the screw rod 35. When the outer tube 5 rotates counterclockwise under the power of the directional drilling rig equipment, the gear one 37 drives the gear two 371 to rotate clockwise through cooperation, at this time, the roller 376 is pushed to the narrow end of the wedge-shaped space 374 under the action of friction and the spring 375, and the outer ring 372 and the inner ring 373 are locked, so as to drive the screw rod 35 passing through the inner ring 373 to rotate synchronously. When the outer tube 5 rotates clockwise, the outer ring 372 will rotate counterclockwise with the gear two 371, so that the roller 376 is pushed to the wide end of the wedge-shaped space 374, and the locking between the outer ring 372 and the inner ring 373 is released, the outer ring 372 idles, and the inner ring 373 does not follow. In this way, by sleeving and fixing the gear one 37 on the outer wall of the outer tube 5 and installing the gear two 371 meshing with the gear one 37 on the corresponding position of the screw rod 35, when the gear one 37 rotates with the outer tube 5, it will transmit torque to drive the gear two 371 to rotate, at this time, the outer ring 372 and the inner ring 373 coaxially installed on the end surface of the gear two 371 will be locked and released to the outer ring 372 and the inner ring 373 under the structure of the spring 375 and the roller 376 and in cooperation with the narrow end and the wide end of the wedge-shaped space 374 machined on the inner side of the outer ring 372, so as to release or not release the metal sleeve 31 in two rotating directions, so as to expand the metal sleeve 31 in the target area of the easy breaking area.

[0031] It should be noted that the gear two 371 and the outer ring 372 are integrally formed.

[0032] In an embodiment, the part of the screw rod 35 between the support ring a 325 and the support ring b 33 is provided with a telescopic cover 7, and the end surface of the support ring b 33 corresponding to the end surface of the support ring a 325 and the position where the guide rod 36 penetrates is provided with a cleaning column 8 for scraping off the sand and rock debris attached to the surface of the guide rod 36. In this way, by installing the telescopic cover 7 on the part of the screw rod 35 between the support ring a 325 and the support ring b 33, and installing the cleaning column 8 on the position where the guide rod 36 penetrates the support ring b 33, the screw rod 35 and the guide rod 36 are effectively protected, preventing sand and rock debris from entering the transmission structure to accelerate wear and tear, effectively preventing jamming, and ensuring normal transmission effect.

[0033] In an embodiment, the dustproof shell 9 is arranged outside each structure included in the transmission assembly c. In this way, by installing the dustproof shell 9 outside each structure included in the transmission assembly c, and by screwing the dustproof shell 9 to the outer end of the fixed ring 34, each structure included in the transmission assembly c can be effectively protected, preventing sand and rock debris from entering to affect its transmission effect.

[0034] The anti-breaking method is used for the anti-breaking device for the horizontal section of the long directional borehole in the floor, and specifically includes the following steps: S1, analyze the lithological characteristics of the close-range coal seam group, and establish a numerical model accordingly. The length of the horizontal directional long borehole is 300-500 m. The deformation and pressure relief and permeability enhancement characteristics of the directional long borehole arranged at different positions between the coal seam group are studied to determine the reasonable arrangement horizon of the directional long borehole. The displacement discontinuity point (the displacement is more than 30% of the diameter of the horizontal section) under the condition of the horizon is determined as the easy breaking area under normal mining conditions.

[0035] S2, position the directional drilling rig equipment, cooperate with multiple drill rods 1 to perform directional long borehole construction in the target area, and divide the structure zone and the fracture zone penetrated by the horizontal section of the directional long borehole into easy breaking areas under abnormal conditions.

[0036] S3, disassemble and remove the drill bit on the corresponding drill rod 1 at the unearthing point, replace the combined back-reaming bit 2 and the injection tube group, continue to use the directional drilling rig equipment, back-drill multiple sequentially combined drill rods 1 from the unearthing point to the earth penetration point, expand the diameter of the long borehole by 30%-50% (for example, from Φ94 mm to Φ120-150 mm) through the back-reaming bit 2, increase the contact buffer space between the borehole and the coal and rock mass, and ensure that the effective extraction passage cross-sectional area is greater than or equal to 60% when the interlayer displacement is less than or equal to 50 mm.

[0037] S4, the high-pressure grouting pump is in place, the inner tube 4 is used, the joint 41 and the two or more than two nozzles 42 uniformly distributed on the joint 41 are matched, and the hole wall of the long borehole is uniformly grouted and consolidated during the rotation of the inner tube 4, wherein the type of slurry is selected according to the crack characteristics (such as single liquid cement slurry or cement-water glass double liquid slurry), the principle of "small amount and multiple times, low pressure and slow injection" is adopted for one-time grouting, the pressure is controlled below 1.5-2.0 MPa; the secondary grouting is carried out after the initial setting of the one-time grouting, the high pressure (2-5 MPa) is applied to force the slurry to penetrate into the small cracks, the compactness of the space around the borehole is improved, and the shear deformation resistance of the borehole is enhanced.

[0038] S5, for the easy broken area determined in step S1, the anti-breaking assembly 3 outside the outer tube 5 is moved to the target easy broken area during the movement of the drill rod 1, at this time, the drill rod 1 is reversely rotated, the multiple arc plates 324 outside the outer tube 5 are synchronously expanded, the metal sleeve 31 is plastically deformed, and the metal sleeve 31 is tightly attached to the hole wall of the long borehole for supporting and reinforcing.

[0039] S6, after the above operation is completed, the broken area position is broken and extracted, and the effect is recorded, so as to provide data support for the next stage of directional long borehole construction and improvement of the anti-breaking process.

[0040] It is supplemented that before the numerical model is established, the coal seam group spacing (such as 5-20 m), the interlayer lithology (mudstone, sandstone, etc.) and the thickness distribution are determined through borehole coring and logging data, and the rock sample mechanical parameters such as compressive strength (UCS), elastic modulus (E), Poisson's ratio (v), cohesion (c), internal friction angle (φ) are obtained by laboratory test, and the soft interlayer is analyzed (such as the softening coefficient of mudstone).

[0041] In the establishment of the numerical model, based on the lithological characteristics, a suitable model (such as FLAC3D, UDEC, PFC) is selected, and the parameters are valued, such as coal seam: Mohr-Coulomb model, parameter example: c=1.5 MPa, φ=30°, E=3 Gpa; soft interlayer: strain softening model, parameter example: c=1 MPa (residual 0.5 MPa), φ=25°; hard rock layer: elastic or Hoek-Brown model, parameter example: UCS=50 MPa, E=20 GPa.

[0042] Directional drilling arrangement and working condition simulation, set up a directional drilling with a diameter of 100-200mm in the model, and arrange along different horizons of coal seam group, such as scheme one: the drilling is located 2m below the upper coal floor (in the weak interlayer); scheme two: the drilling is located in the middle of the two coal seams (in the hard rock layer); scheme three: the drilling is close to the upper coal floor (stress concentration area). Step excavation is adopted: first, initial balance→upper coal mining→stress redistribution (monitoring drilling deformation); second, lower coal mining→analysis of pressure relief and permeability improvement effect (permeability change).

[0043] Deformation and pressure relief and permeability improvement feature analysis, based on key monitoring indicators (such as drilling deformation: radial displacement (ΔD), focus on ΔD>30% of the hole diameter (such as hole diameter 150mm, mutation threshold 45mm); stress evolution: vertical stress reduction rate (pressure relief effect, such as >30% is effective); permeability change: calculate the permeability improvement effect through the pore pressure-permeability coupling model), extract the horizon corresponding to the displacement mutation point (ΔD>30% of the hole diameter), and mark it as the easy-to-break area.

[0044] Model verification and optimization, compare microseismic monitoring data, drilling peep results and simulated displacement distribution, calibrate model parameters (such as adjust the c and φ values of the weak interlayer).

[0045] In addition, the core of the numerical model is the accuracy of the lithology parameters and the rationality of the boundary conditions, which needs to be calibrated repeatedly combined with engineering experience.

[0046] The control mode of the electrical components appearing in this paper is automatically controlled by a controller. The control circuit of the controller can be realized by simple programming by those skilled in the art. The power supply also belongs to the common knowledge in the art, and the present application mainly protects mechanical devices, so the control mode and circuit connection will not be explained in detail.

[0047] It should be noted that if the present application involves directional indications (such as up, down, left, right, front, back, etc.) in the embodiments, the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0048] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, nor within the protection scope required by the present application.

[0049] In addition, "a plurality of" means two or more.

[0050] The above only describes the preferred embodiments of the present application, and does not limit the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A breakage-preventing device for a floor directional long-hole horizontal section, characterized in that, The utility model relates to a long drilling construction equipment for horizontal section among coal seams, which comprises a drill rod (1), a back reaming drill bit (2), a grouting pipe group and a breakage prevention assembly (3). The drill rod (1) is provided with a plurality of drill rods (1) which are sequentially combined and matched with the directional drilling rig equipment to carry out long drilling construction of the horizontal section among coal seams. The back reaming drill bit (2) is detachably arranged at the end of the drill rod (1) initially entering the soil and is used for entering the back drilling following the drill rod (1) from the soil outlet point and expanding the long drilling hole. The grouting pipe group is detachably arranged at the end of the back reaming drill bit (2) away from the drill rod (1) and is used for consolidating the hole wall of the long drilling hole. The breakage prevention assembly (3) is arranged outside the grouting pipe group and is used for supporting and reinforcing the designated area in the long drilling hole.

2. The breakage-preventing device for the horizontal section of the long directional borehole of the floor according to claim 1, characterized in that: The grouting pipe group comprises an inner pipe (4) and an outer pipe (5) which are coaxially sleeved from inside to outside. When the inner pipe (4) rotates, the inner pipe (4) uniformly sprays grouting to the hole wall of the long drilling hole through the two or more than two nozzles (42) uniformly distributed on the outer periphery of the joint (41).

3. The breakage-preventing device for the horizontal section of the long directional borehole of the floor according to claim 2, characterized in that: The inner pipe (4) and the outer pipe (5) are provided with a transmission assembly a at the joint end for driving the inner pipe (4) and the outer pipe (5) to synchronously rotate. The transmission assembly a comprises an outer gear ring (6) sleeved on the outer wall of the inner pipe (4) and close to the joint (41) and an inner gear ring (61) coaxially arranged on the inner wall of the outer pipe (5).

4. The breakage-preventing device for the horizontal section of the long directional borehole of the floor panel according to claim 3, characterized in that: The breakage prevention assembly (3) comprises a metal sleeve (31) supporting the hole wall of the long drilling hole and a synchronous expansion mechanism (32) matched with the metal sleeve (31) and expanding the metal sleeve (31). The synchronous expansion mechanism (32) comprises a movable sliding sleeve (321) slidingly arranged on the outer wall of the outer pipe (5), a plurality of wedge-shaped groups a symmetrically distributed on the movable sliding sleeve (321), each wedge-shaped group a being composed of two or more than two first wedge-shaped blocks (322) and being uniformly distributed along the length direction of the movable sliding sleeve (321), each first wedge-shaped block (322) being provided with a second wedge-shaped block (323) on the inclined surface in a matched mode, a plurality of second wedge-shaped blocks (323) arranged along the length direction of the movable sliding sleeve (321) forming a wedge-shaped group b, the outer end of the wedge-shaped group b being fixed with an arc plate (324), the number of the arc plates (324) being the same as that of the wedge-shaped groups a, and a plurality of arc plates (324) being combined to form a petal structure, and the outer wall of each arc plate (324) being in contact with the inner wall of the metal sleeve (31).

5. The breakage prevention device for the horizontal section of the long directional borehole of the floor orientation according to claim 4, characterized in that: The movable sliding sleeve (321) is provided with a support ring a (325) at one end close to the arc plate (324) and in relative sliding mode, the support ring a (325) is provided with the same number of sliding grooves (326) as the arc plate (324), the arc plate (324) is provided with a sliding block (327) which is limited in radial direction and moves along the movable sliding sleeve (321), and the sliding block (327) is provided in sliding mode in cooperation with the sliding grooves (326).

6. The breakage prevention device for the horizontal section of the long directional borehole of the floor orientation according to claim 5, characterized in that: The anti-breaking assembly (3) further comprises a transmission assembly b provided on the outer tube (5) and used for driving the movable sliding sleeve (321) to move; The transmission assembly b comprises a support ring b (33) provided at the end of the movable sliding sleeve (321), a fixed ring (34) provided adjacent to and spaced from one side of the support ring b (33), screw rods (35) and guide rods (36) provided on both sides of the fixed ring (34) respectively, one end of the screw rod (35) is connected with the support ring b (33) in cooperation, and one end of the guide rod (36) is connected with the support ring b (33) in sliding and guiding mode at a corresponding position.

7. The breakage prevention device for the horizontal section of the long directional borehole of the floor panel according to claim 6, wherein: The outer end of the fixed ring (34) is provided with a transmission assembly c; The transmission assembly c comprises a gear one (37) provided on the outer wall of the outer tube (5), a gear two (371) connected with the gear one (37) in cooperation and provided outside the screw rod (35), an outer ring (372) and an inner ring (373) coaxially sleeved and provided on the end face of the gear two (371), a plurality of wedge-shaped spaces (374) uniformly provided on the inner wall of the outer ring (372), a spring (375) provided in each wedge-shaped space (374) along the tangent of the inner ring (373), a roller (376) provided on the end of the spring (375) close to the inner ring (373), and the inner ring (373) is sleeved and fixed on the outer wall of the screw rod (35); When the outer tube (5) rotates counterclockwise under the power of the directional drilling rig equipment, the gear one (37) and the gear two (371) are matched to drive the gear two (371) to rotate clockwise, at this time, the roller (376) is pushed to the narrow end of the wedge-shaped space (374) under the action of friction and the spring (375), and the outer ring (372) and the inner ring (373) are locked, so as to drive the screw rod (35) penetrating through the inner ring (373) to rotate synchronously; When the outer tube (5) rotates clockwise, the outer ring (372) will rotate counterclockwise with the gear two (371), so that the roller (376) is pushed to the wide end of the wedge-shaped space (374), the locking between the outer ring (372) and the inner ring (373) is released, the outer ring (372) idles, and the inner ring (373) does not follow.

8. The breakage prevention apparatus for the horizontal section of the long directional borehole of the floor orientation according to claim 6, characterized by: The part segment of the screw rod (35) between the support ring a (325) and the support ring b (33) is provided with a telescopic cover (7) which is telescopic and folded, the end face of the support ring b (33) corresponding to the end face of the support ring a (325) and located at the position where the guide rod (36) penetrates and slides is provided with a cleaning column block (8), and the cleaning column block (8) is used for scraping off the sand and rock debris attached to the surface of the guide rod (36).

9. The breakage prevention apparatus for the horizontal section of the long directional borehole of the floor orientation according to claim 7, characterized by: The dustproof shell (9) is arranged outside each structure included in the transmission assembly c.

10. A method of preventing breakage using the apparatus for preventing breakage of a horizontal section of a long directional borehole in a floor as claimed in any one of claims 1 to 9, characterised by, Specifically comprising the following steps: S1, analyze the interlayer lithology characteristics of the coal seam group, establish a numerical model, determine the reasonable arrangement horizon and the easy breaking area of the directional long borehole based on the deformation and pressure relief and permeability improvement characteristics of the directional long borehole at different positions between the coal seam group; S2, position the directional drilling rig equipment, and cooperate with multiple drill rods (1) to perform directional long borehole construction in the target area; S3, disassemble and remove the drill bit on the corresponding drill rod (1) at the unearthed point position, replace the combined back-reaming drill bit (2) and injection tube group, continue to use the directional drilling rig equipment, back drill multiple sequentially combined drill rods (1) from the unearthed point to the earth penetration point, and expand the hole diameter of the long borehole through the back-reaming drill bit (2); S4, position the high-pressure grouting pump, use the inner tube (4), cooperate with the joint (41) and the two or more than two nozzles (42) uniformly distributed on the joint (41) to uniformly grout and consolidate the hole wall of the long borehole during the rotation of the inner tube (4); S5, for the easy breaking area determined in step S1, move the anti-breaking assembly (3) outside the outer tube (5) to the target easy breaking area during the movement of the drill rod (1) back drilling, and then reversely rotate the drill rod (1) to synchronously expand the multiple arc plates (324) uniformly distributed outside, so that the metal sleeve (31) is plastically deformed and tightly attached to the hole wall of the long borehole for supporting and reinforcing; S6, after the above operation is completed, the easy breaking area position is broken and extracted, and the effect is recorded to provide data support for the next stage of directional long borehole construction and improvement of the anti-breaking process.

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