Directional horizontal hole advance exploration of coal mine fault coring device and method for preventing core sliding

Abstract

The present invention discloses a directional horizontal hole advance exploration coal mine fault coring device and a method for preventing core slippage, comprising an outer cylinder and an inner cylinder coaxially arranged in the outer cylinder, a coring drill bit coaxially installed on the front end of the outer cylinder, a core claw assembly coaxially installed on the front end of the inner cylinder, the core claw assembly is located in the coring drill bit, and the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit is greater than zero; a roller bearing is installed between the core claw assembly and the coring drill bit, and a rotating assembly component is coaxially installed in the rear end of the outer cylinder. The present invention can ensure high core integrity, not easy to break, and high core success rate during horizontal coring; by setting the front end of the core claw seat as a conical hole, the outer wall of the core can be squeezed and strengthened to ensure the integrity of the coring and avoid the core from spreading, and the friction between the core claw seat and the core can be increased when pulling the drill.

Description

Technical Field

[0001] The invention relates to the technical field of horizontal exploration of coal mine faults, and more particularly to a device for coring coal mine faults by directional horizontal hole advance exploration and a method for preventing cores from sliding off. Background Art

[0002] With the gradual increase in the scale, depth and complexity of coal mining, the safety production threats faced by mines are becoming more and more serious. According to incomplete statistics, among the major coal mine accidents, various major accidents related to geological structures account for 80%. Faults, as the main geological structures in coal mines, have a direct or indirect relationship with the occurrence of disasters. Therefore, doing a good job in the exploration of faults in coal mines will, to a certain extent, play a role in protecting the safety production of mines. At present, the domestic fault exploration technology is still in the development stage. At present, coal mines often use geophysical exploration methods such as three-dimensional seismic, electrical method, geological radar, conventional drilling methods and directional horizontal hole methods to explore faults. Among them, geophysical exploration methods have the following main disadvantages: 1. The error in judging the horizontal position is often between -30 and +30m; 2. There are multiple solutions for geological anomalies; 3. The exploration conclusions lack physical comparison and are not intuitive enough; the geophysical exploration results must be verified by drilling methods, and faults must be identified based on drilling cuttings, changes in drilling parameters, changes in simple hydrogeological parameters, logging data, etc. Among them, conventional drilling exploration methods include rock coring devices, but directional horizontal holes lack corresponding rock coring devices, and cannot perform multi-factor coupling analysis and accurate measurement and control of faults. Summary of the invention

[0003] To this end, the technical problem to be solved by the present invention is to provide a directional horizontal hole advance exploration coal mine fault coring device suitable for ground directional horizontal hole advance exploration fault coring and a method for preventing core sliding.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a directional horizontal hole advance exploration coal mine fault coring device, comprising an outer cylinder and an inner cylinder coaxially arranged in the outer cylinder, a coring drill bit is coaxially installed on the front end of the outer cylinder, a core claw assembly is coaxially installed on the front end of the inner cylinder, the core claw assembly is located in the coring drill bit, and the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit is greater than zero; a roller bearing is installed between the core claw assembly and the coring drill bit, a rotating assembly component is coaxially installed in the rear end of the outer cylinder, the rotating assembly component is axially fixed to the outer cylinder, an axial adjustment component is installed on the front end of the rotating assembly component, and the front end of the axial adjustment component is connected to the rear end of the inner cylinder; a front stabilizer and a rear stabilizer are respectively installed on both ends of the cylinder wall of the outer cylinder.

[0005] The above-mentioned directional horizontal hole advance exploration coal mine fault coring device, the rotating assembly component includes a hollow rotating shaft, a thrust bearing, a key, a radial bearing and a carrier nut, the carrier nut is coaxially fixedly installed in the rear end of the outer cylinder, the rear end of the hollow rotating shaft is coaxially inserted into the carrier nut, a shoulder is provided on the hollow rotating shaft, and the thrust bearing, the key and the radial bearing are coaxially installed in sequence from the shoulder position to the rear end position on the hollow rotating shaft, the front end of the thrust bearing is against the shoulder, and the two ends of the key are respectively The hollow rotating shaft is respectively fitted with the rear end of the thrust bearing and the front end of the radial bearing, a limiting groove is provided on the upper part of the hollow rotating shaft behind the radial bearing, a retaining ring is installed in the limiting groove, and the retaining ring is pressed against the rear end of the radial bearing; a limiting ring is provided on the front end inner wall of the carrier nut, the front end of the thrust bearing is pressed against the limiting ring, and the front end outer diameter of the thrust bearing is matched with the front end inner diameter of the carrier nut, a shunt joint is installed on the rear end of the outer cylinder, and the front end of the shunt joint is connected to the rear end of the carrier nut.

[0006] The above-mentioned directional horizontal hole advance exploration of coal mine fault coring device, the axial adjustment component includes a rear connecting sleeve, a stop ring and a locking nut, an external thread is provided on the front end outer wall of the hollow rotating shaft, the rear connecting sleeve and the stop ring are sequentially sleeved on the front end of the hollow rotating shaft from front to back, the locking nut is threadedly connected to the hollow rotating shaft and presses against the stop ring and the rear connecting sleeve; an external thread is provided on the front end outer wall of the rear connecting sleeve, an internal thread is provided on the rear end inner wall of the inner tube, and the rear end of the inner tube is threadedly connected to the front end of the rear connecting sleeve.

[0007] The above-mentioned directional horizontal hole advance exploration of coal mine fault coring device has a mud hole in the middle of the side wall of the hollow rotating shaft, and the mud hole is arranged obliquely; a sealing retaining ring is coaxially fixedly installed in the front end of the hollow rotating shaft, and a steel ball is installed in the hollow rotating shaft, and the steel ball is sealed and fitted with the rear end of the sealing retaining ring.

[0008] The above-mentioned directional horizontal hole advance exploration of coal mine fault coring device, the core claw assembly includes a core claw seat and a core claw, the core claw seat is coaxially installed in the coring drill bit, the rear end of the core claw seat is threadedly connected to the front connecting sleeve, the rear end of the front connecting sleeve is threadedly connected to the front end of the inner tube, and the core claws are evenly arranged along the circumference of the core claw seat; the outer side of the roller bearing is supported on the inner wall surface of the coring drill bit, and the inner side of the roller bearing is supported on the outer wall surface of the core claw seat.

[0009] The above-mentioned directional horizontal hole advance exploration coal mine fault coring device, when coring in soft strata: the distance from the front end face of the core claw seat to the inner shoulder surface is 6-11mm; when coring in hard strata: the distance from the front end face of the core claw seat to the inner shoulder surface is 11-16mm.

[0010] The above-mentioned directional horizontal hole advance exploration of coal mine fault coring device, the front end center hole of the core claw seat is a conical hole, the front end inner diameter of the conical hole gradually decreases to the inner diameter of the position where the core claw is installed on the core claw seat, and the front end inner diameter of the conical hole is smaller than the inner diameter of the coring drill bit; an inner chamfer is provided on the front end of the conical hole, and the maximum inner diameter of the inner chamfer is larger than the inner diameter of the coring drill bit; the inner diameter of the inner cylinder is equal to the inner diameter of the front connecting sleeve, and the inner diameter of the inner cylinder is larger than the minimum inner diameter of the conical hole and smaller than the maximum inner diameter of the conical hole, which can ensure that the core can smoothly enter the inner cylinder, and at the same time ensure the fit between the core and the inner cylinder to avoid the core being too loose or too tight.

[0011] In the above-mentioned directional horizontal hole advance exploration coal mine fault coring device, the cross-sectional contour lines of the front centralizer and the rear centralizer are both arc-shaped, and the middle outer diameter of the front centralizer and the rear centralizer gradually decreases to the outer diameters of the two ends.

[0012] The method for preventing core slippage by coring in coal mine faults by directional horizontal hole advance exploration comprises the following steps:

[0013] Step A: Assemble a directional horizontal hole advance exploration coal mine fault coring device: The directional horizontal hole advance exploration coal mine fault coring device comprises an outer cylinder and an inner cylinder coaxially arranged in the outer cylinder, a coring drill bit is coaxially installed on the front end of the outer cylinder, a core claw assembly is coaxially installed on the front end of the inner cylinder, the core claw assembly is located in the coring drill bit, and the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit is greater than zero; a roller bearing is installed between the core claw assembly and the coring drill bit, a rotating assembly assembly is coaxially installed in the rear end of the outer cylinder, the rotating assembly assembly is axially fixed to the outer cylinder, an axial adjustment assembly is installed on the front end of the rotating assembly assembly, and the front end of the axial adjustment assembly is connected to the rear end of the inner cylinder; a front stabilizer and a rear stabilizer are respectively installed on both ends of the cylinder wall of the outer cylinder;

[0014] Step B: Calculate the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit according to the on-site formation hardness: the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit is recorded as C, measure the distance from the front end face of the core claw assembly to the front end face of the outer cylinder and record the length as B, measure the distance from the inner shoulder surface of the coring drill bit to the front end face of the outer cylinder and record the length as A, and the result obtained by subtracting the B value from the A value is the C value;

[0015] Step C: Adjust the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit through the axial adjustment component until the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit is equal to the C value.

[0016] The above-mentioned directional horizontal hole advance exploration method for coring and preventing core sliding in coal mine faults has a C value of 6-11 mm when coring in soft formations and a C value of 11-16 mm when coring in hard formations.

[0017] The technical solution of the present invention achieves the following beneficial technical effects:

[0018] 1. The present invention can ensure high integrity of the core during horizontal coring, making it less prone to breakage and achieving a high success rate of coring. By setting the front end of the core claw seat as a tapered hole and matching it with the central hole of the coring drill bit, when coring, the core enters the coring drill bit and can enter the tapered hole through the chamfering guide. As the core continues to move forward, under the action of the tapered hole, the core is guided to ensure the coaxial rate of coring, and the outer wall of the core can be squeezed and strengthened to ensure the integrity of the coring and avoid the core from spreading. When pulling out the drill, the friction between the core claw seat and the core can be increased. Secondly, after the slurry flushes the surface of the core, its outer diameter will be slightly reduced, and the tapered hole can be used to ensure that it always fits the core.

[0019] 2. Since mud circulation needs to be ensured when coring during drilling, the slurry will flush the surface of the core, causing the core surface to be damaged and causing the core to fall off during the drilling process, resulting in coring failure. The present invention, by providing an axial adjustment component, can adjust the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit, thereby achieving control of the mud flushing amount to adapt to formation conditions of different hardness, thereby ensuring the integrity of the core and the success rate of coring.

[0020] 3. The present invention can greatly improve the straightening effect by arranging two front and rear straighteners, and the straightener is shaped like a waist drum, and the tangent length with the well wall is short, so that the inner tube has a greater stability ability; by arranging radial bearings, thrust bearings and roller bearings, a stable support effect can be formed at both ends of the inner tube, so that the inner tube can face the throat of the coring drill bit, so that the core can smoothly enter the inner tube and be protected, and this structure can prevent the inner tube from rotating, so that when the tool is in a horizontal position, it can play a role in straightening the inner tube, which is beneficial to improving the core acquisition rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic cross-sectional view of the coring device of the present invention;

[0022] Figure 2 A schematic cross-sectional view of the rear end of the coring device of the present invention;

[0023] Figure 3A schematic cross-sectional structure diagram of the front end of the coring device of the present invention.

[0024] The reference numerals in the figure are as follows: 1-diverter joint; 2-radial bearing; 3-thrust bearing; 4-rear stabilizer; 5-steel ball; 6-outer cylinder; 7-inner cylinder; 8-front stabilizer; 9-core claw; 10-roller bearing; 11-coring drill bit; 12-core claw seat; 13-front connecting sleeve; 14-rear connecting sleeve; 15-stop ring; 16-locking nut; 17-hollow rotating shaft; 18-carrier nut; 19-key; 20-retaining ring. DETAILED DESCRIPTION

[0025] Example 1

[0026] The directional horizontal hole advance exploration coal mine fault coring device in this embodiment can be found in Figure 1-3 , comprising an outer cylinder 6 and an inner cylinder 7 coaxially arranged in the outer cylinder 6, a coring drill bit 11 is coaxially mounted on the front end of the outer cylinder 6, a core claw assembly is coaxially mounted on the front end of the inner cylinder 7, the core claw assembly is located in the coring drill bit 11, and the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit 11 is greater than zero; a roller bearing 10 is installed between the core claw assembly and the coring drill bit 11, a rotating assembly assembly is coaxially mounted in the rear end of the outer cylinder 6, and the rotating assembly assembly is connected to the core claw assembly assembly. The outer cylinder 6 is axially fixed, and an axial adjustment component is installed on the front end of the rotating assembly component. The front end of the axial adjustment component is connected to the rear end of the inner cylinder 7. The outer cylinder 6 plus two stabilizers is 5100mm long. There are support points at both ends of the outer cylinder 6, which has strong bending resistance, is conducive to improving the core recovery rate, single-cylinder footage and extending the service life of the diamond coring drill bit. It is suitable for coring operations in horizontal holes with a medium curvature radius of Ф149.2-Ф215.9mm wellbores, and the maximum inclination rate it can pass is 48.15° / 100m.

[0027] like Figure 2 As shown, a front stabilizer 8 and a rear stabilizer 4 are respectively installed on both ends of the cylinder wall of the outer cylinder 6. The cross-sectional contour lines of the front stabilizer 8 and the rear stabilizer 4 are both arc-shaped. The outer diameters of the front stabilizer 8 and the rear stabilizer 4 gradually decrease from the middle to the outer diameters of the two ends. The front stabilizer 8 is close to the drill bit, and the rear stabilizer 4 is 4600mm away from the drill bit, so that the outer cylinder 6 has a greater stability and can improve the mechanical drilling speed.

[0028] like Figure 2As shown, the rotating assembly component includes a hollow rotating shaft 17, a thrust bearing 3, a key 19, a radial bearing 2 and a carrier nut 18. The carrier nut 18 is coaxially fixedly installed in the rear end of the outer cylinder 6. The rear end of the hollow rotating shaft 17 is coaxially inserted into the carrier nut 18. A shoulder is provided on the hollow rotating shaft 17. The thrust bearing 3, the key 19 and the radial bearing 2 are coaxially installed on the hollow rotating shaft 17 in sequence from the shoulder position to the rear end position. The front end of the thrust bearing 3 is pressed against the shoulder, and the two ends of the key 19 are respectively fitted with the rear end of the thrust bearing 3 and the front end of the radial bearing 2. The upper portion of the hollow rotating shaft 17 is located at A limiting groove is provided at the rear of the radial bearing 2, a retaining ring 20 is installed in the limiting groove, and the retaining ring 20 abuts against the rear end of the radial bearing 2; a limiting ring is provided on the front end inner wall of the carrier nut 18, the front end of the thrust bearing 3 abuts against the limiting ring, and the front end outer diameter of the thrust bearing 3 matches the front end inner diameter of the carrier nut 18; a diverter joint 1 is installed on the rear end of the outer cylinder 6, and the front end of the diverter joint 1 is connected to the rear end of the carrier nut 18; the radial bearing 2, the thrust bearing 3 and the roller bearing 10 are all clipless and have no seals at both ends, so a small amount of mud can be allowed to flow through to cool and lubricate the bearings, and the structure is simple, the rotation is flexible, and the service life is long.

[0029] The axial adjustment assembly includes a rear connecting sleeve 14, a stop ring 15 and a locking nut 16. An external thread is provided on the front end outer wall of the hollow rotating shaft 17. The rear connecting sleeve 14 and the stop ring 15 are sequentially sleeved on the front end of the hollow rotating shaft 17 from front to back. The locking nut 16 is threadedly connected to the hollow rotating shaft 17 and presses against the stop ring 15 and the rear connecting sleeve 14. An external thread is provided on the front end outer wall of the rear connecting sleeve 14, and an internal thread is provided on the rear end inner wall of the inner tube 7. The rear end of the inner tube 7 is threadedly connected to the front end of the rear connecting sleeve 14.

[0030] A mud hole is opened in the middle of the side wall of the hollow rotating shaft 17, and the mud hole is set obliquely; a sealing ring is coaxially fixedly installed in the front end of the hollow rotating shaft 17, and a steel ball 5 is installed in the hollow rotating shaft 17, and the steel ball 5 is sealed and fitted with the rear end of the sealing ring.

[0031] like Figure 3As shown, the core claw assembly includes a core claw seat 12 and a core claw 9. The core claw seat 12 is coaxially installed in the coring drill bit 11. The rear end of the core claw seat 12 is threadedly connected to the front connecting sleeve 13. The rear end of the front connecting sleeve 13 is threadedly connected to the front end of the inner tube 7. The core claws 9 are evenly arranged along the circumference of the core claw seat 12; the outer side of the roller bearing 10 is supported on the inner wall surface of the coring drill bit 11, and the inner side of the roller bearing 10 is supported on the outer wall surface of the core claw seat 12.

[0032] When coring in soft formations: the distance from the front end face of the core claw seat 12 to the inner shoulder surface is 6-11mm; when coring in hard formations: the distance from the front end face of the core claw seat 12 to the inner shoulder surface is 11-16mm. Since mud circulation needs to be ensured when coring during drilling, the slurry flushes the surface of the core, destroys the surface of the core, and causes the core to fall off during the drilling process, resulting in coring failure. By setting an axial adjustment component, the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit 11 can be adjusted to achieve control of the mud flushing amount to adapt to formation conditions of different hardness and ensure the integrity of the core and the success rate of coring.

[0033] The front end center hole of the core claw seat 12 is a tapered hole, and the inner diameter of the front end of the tapered hole gradually decreases to the position where the core claw 9 is installed on the core claw seat 12, and the front end inner diameter of the tapered hole is smaller than the inner diameter of the coring drill bit 11; the front end of the tapered hole is provided with an inner chamfer, and the maximum inner diameter of the inner chamfer is larger than the inner diameter of the coring drill bit 11; the inner diameter of the inner cylinder 7 is equal to the inner diameter of the front connecting sleeve 13, and the inner diameter of the inner cylinder 7 is larger than the minimum inner diameter of the tapered hole and smaller than the maximum inner diameter of the tapered hole. The conical hole is arranged to match the central hole of the coring drill bit 11. When coring, the core enters the coring drill bit 11 and can enter the conical hole through the chamfering guide. As the core continues to move forward, under the action of the conical hole, the core is guided to ensure the coaxial rate of coring, and the outer wall of the core can be squeezed and strengthened to ensure the integrity of the coring and avoid the core from spreading. When pulling out the drill, the friction between the core claw seat 12 and the core can be increased; secondly, after the slurry flushes the surface of the core, its outer diameter will be slightly reduced, and the conical hole can be used to ensure that it is always in contact with the core.

[0034] Example 2

[0035] Adjustments are made on the basis of the directional horizontal hole advance exploration of coal mine fault coring device in Example 1 to implement a directional horizontal hole advance exploration of coal mine fault coring and prevention of core sliding method, including the following steps:

[0036] Step A: Assemble a directional horizontal hole advance exploration coal mine fault coring device: The directional horizontal hole advance exploration coal mine fault coring device comprises an outer cylinder 6 and an inner cylinder 7 coaxially arranged in the outer cylinder 6, a coring drill bit 11 is coaxially installed on the front end of the outer cylinder 6, a core claw assembly is coaxially installed on the front end of the inner cylinder 7, the core claw assembly is located in the coring drill bit 11, and the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit 11 is greater than zero; a roller bearing 10 is installed between the core claw assembly and the coring drill bit 11, a rotating assembly assembly is coaxially installed in the rear end of the outer cylinder 6, the rotating assembly assembly is axially fixed to the outer cylinder 6, an axial adjustment assembly is installed on the front end of the rotating assembly assembly, and the front end of the axial adjustment assembly is connected to the rear end of the inner cylinder 7; a front centralizer 8 and a rear centralizer 4 are respectively installed on both ends of the cylinder wall of the outer cylinder 6;

[0037] Step B: Calculate the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit 11 according to the on-site formation hardness: the distance value from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit 11 is recorded as C, measure the distance from the front end face of the core claw assembly to the front end face of the outer tube 6 and record the length value as B, measure the distance from the inner shoulder surface of the coring drill bit 11 to the front end face of the outer tube 6 and record the length value as A, and the result obtained by subtracting the B value from the A value is the C value;

[0038] Step C: Adjust the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit 11 through the axial adjustment component until the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit 11 is equal to the C value.

[0039] When coring in soft formations: C value is 6-11mm; when coring in hard formations: C value is 11-16mm

[0040] Workflow: 1. Before coring, use conventional drilling tools to clear the wellbore to ensure that there is no sand or metal falling at the bottom of the well;

[0041] 2. Check the coring device: ensure that all rotating parts rotate flexibly; there are no defects such as biting deviation and cracks at the connection, and the thread is intact; the core claw 9 moves up and down smoothly;

[0042] 3. When assembling the coring device at the well site, tighten the selected core claw assembly, front stabilizer 8 and rear stabilizer 4; remove the outer tube wire guard, measure the length from the outer end face of the core claw assembly to the outer tube body, record the length value B, and then put on the wire guard; measure the length from the inner shoulder of the coring drill bit 11 to the outer tube body and record the length value A; use the lifting short section to lift the inner and outer tubes onto the drilling platform at the same time, press the drill collar into the wellbore, and lock it with a safety slip;

[0043] 4. Pre-adjust the longitudinal clearance between the end face of the core claw seat 12 and the inner shoulder of the core drill bit 11 according to the above A and B values, that is, the result C obtained by subtracting B from A. After the adjustment, remove the chuck of the inner tube 7 and lower the inner tube 7, then tighten the external thread of the diverter joint 1 and the internal thread of the outer tube 6. If it is not suitable, continue to adjust;

[0044] 5. After drilling, fully circulate the drilling fluid. After the circulation is completed, slowly lower the drill bit to allow the drill bit to touch the bottom of the well. Use the minimum speed, displacement, and light drilling pressure for test operation. If the operation is stable, when the bottom of the well matches the shape of the drill bit, gradually adjust to the recommended coring parameters;

[0045] 6. When cutting the core, slowly lift the drill bit and pay attention to the display of the weight gauge. Generally, the hanging weight is increased by 50-150KN and then immediately removed, which proves that the core is pulled out. If the hanging weight is increased by 50-150KN and remains stable without decreasing, stop lifting the drill bit, keep the core in tension, increase the mud pump displacement circulation, until the core is pulled out; raise the core extractor to remove the core from the barrel.

[0046] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A directional horizontal hole advanced exploration coal mine fault coring device, characterized in that: The invention comprises an outer cylinder (6) and an inner cylinder (7) coaxially arranged in the outer cylinder (6); a coring drill bit (11) is coaxially mounted on the front end of the outer cylinder (6); a core claw assembly is coaxially mounted on the front end of the inner cylinder (7); the core claw assembly is located in the core drill bit (11); a distance between the front end face of the core claw assembly and the inner shoulder surface of the core drill bit (11) is greater than zero; a roller bearing (10) is mounted between the core claw assembly and the core drill bit (11); a rotating assembly is coaxially mounted in the rear end of the outer cylinder (6); the rotating assembly is axially fixed to the outer cylinder (6); an axial adjustment assembly is mounted on the front end of the rotating assembly; the front end of the axial adjustment assembly is connected to the rear end of the inner cylinder (7); a front centralizer (8) and a rear centralizer (4) are mounted on both ends of the cylinder wall of the outer cylinder (6); The rotating assembly component comprises a hollow rotating shaft (17), a thrust bearing (3), a key (19), a radial bearing (2) and a carrier nut (18); the carrier nut (18) is coaxially fixedly mounted inside the rear end of the outer cylinder (6); the rear end of the hollow rotating shaft (17) is coaxially inserted into the carrier nut (18); a shoulder is provided on the hollow rotating shaft (17); the thrust bearing (3), the key (19) and the radial bearing (2) are coaxially mounted on the hollow rotating shaft (17) in sequence from the shoulder position to the rear end position; the front end of the thrust bearing (3) abuts against the shoulder; two ends of the key (19) are respectively engaged with the thrust bearing (3). The rear end of the bearing (3) fits with the front end of the radial bearing (2); a limit groove is provided on the upper portion of the hollow rotating shaft (17) at the rear of the radial bearing (2); a retaining ring (20) is installed in the limit groove, and the retaining ring (20) abuts against the rear end of the radial bearing (2); a limit ring is provided on the inner wall of the front end of the carrier nut (18), and the front end of the thrust bearing (3) abuts against the limit ring, and the outer diameter of the front end of the thrust bearing (3) matches the inner diameter of the front end of the carrier nut (18); a flow divider (1) is installed on the rear end of the outer cylinder (6), and the front end of the flow divider (1) is connected to the rear end of the carrier nut (18); The axial adjustment assembly comprises a rear connecting sleeve (14), a stop ring (15) and a locking nut (16); an external thread is provided on the front end outer wall of the hollow rotating shaft (17); the rear connecting sleeve (14) and the stop ring (15) are sequentially sleeved on the front end of the hollow rotating shaft (17) from front to back; the locking nut (16) is threadedly connected to the hollow rotating shaft (17) and abuts against the stop ring (15) and the rear connecting sleeve (14); an external thread is provided on the front end outer wall of the rear connecting sleeve (14); an internal thread is provided on the rear end inner wall of the inner tube (7); the rear end of the inner tube (7) is threadedly connected to the front end of the rear connecting sleeve (14); A mud hole is provided in the middle of the side wall of the hollow rotating shaft (17), and the mud hole is arranged obliquely; a sealing retaining ring is coaxially fixedly installed in the front end of the hollow rotating shaft (17), and a steel ball (5) is installed in the hollow rotating shaft (17), and the steel ball (5) is sealed and fitted with the rear end of the sealing retaining ring; The core claw assembly comprises a core claw seat (12) and a core claw (9); the core claw seat (12) is coaxially mounted in the coring drill bit (11); the rear end of the core claw seat (12) is threadedly connected to a front connecting sleeve (13); the rear end of the front connecting sleeve (13) is threadedly connected to the front end of the inner tube (7); the core claws (9) are evenly arranged in the core claw seat (12) along its circumference; the outer side of the roller bearing (10) is supported on the inner side wall surface of the coring drill bit (11); the inner side of the roller bearing (10) is supported on the outer side wall surface of the core claw seat (12); when coring in a soft formation: the distance from the front end surface of the core claw seat (12) to the inner shoulder surface is 6-11 mm; when coring in a hard formation: the distance from the front end surface of the core claw seat (12) to the inner shoulder surface is 11-16 mm; The front end center hole of the core claw seat (12) is a tapered hole, the front end inner diameter of the tapered hole gradually decreases to the position where the core claw (9) is installed on the core claw seat (12), and the front end inner diameter of the tapered hole is smaller than the inner diameter of the coring drill bit (11); an inner chamfer is provided on the front end of the tapered hole, and the maximum inner diameter of the inner chamfer is larger than the inner diameter of the coring drill bit (11); the inner diameter of the inner cylinder (7) is equal to the inner diameter of the front connecting sleeve (13), and the inner diameter of the inner cylinder (7) is larger than the minimum inner diameter of the tapered hole and smaller than the maximum inner diameter of the tapered hole.

2. The directional horizontal hole advance exploration coal mine fault coring device according to claim 1 is characterized in that: The cross-sectional contour lines of the front centralizer (8) and the rear centralizer (4) are both arc-shaped, and the outer diameters of the front centralizer (8) and the rear centralizer (4) gradually decrease from the middle to the two ends.

3. A method for preventing core slippage by using directional horizontal holes to advance the exploration of coal mine faults and coring, characterized in that: The following steps are involved: Step A: Assembling a directional horizontal hole advance exploration coal mine fault coring device: The directional horizontal hole advance exploration coal mine fault coring device comprises an outer cylinder (6) and an inner cylinder (7) coaxially arranged in the outer cylinder (6), a coring drill bit (11) is coaxially mounted on the front end of the outer cylinder (6), a core claw assembly is coaxially mounted on the front end of the inner cylinder (7), the core claw assembly is located in the coring drill bit (11), and the front end face of the core claw assembly is connected to the inner shoulder of the coring drill bit (11). The distance between the core claw assembly and the coring drill bit (11) is greater than zero; a roller bearing (10) is installed between the core claw assembly and the coring drill bit (11); a rotating assembly component is coaxially installed inside the rear end of the outer cylinder (6); the rotating assembly component is axially fixed to the outer cylinder (6); an axial adjustment component is installed on the front end of the rotating assembly component; the front end of the axial adjustment component is connected to the rear end of the inner cylinder (7); a front stabilizer (8) and a rear stabilizer (4) are respectively installed on both ends of the cylinder wall of the outer cylinder (6); Step B: Calculate the distance from the front end face of the core claw assembly to the inner shoulder face of the coring drill bit (11) according to the hardness of the on-site formation: the distance value from the front end face of the core claw assembly to the inner shoulder face of the coring drill bit (11) is recorded as C, measure the distance from the front end face of the core claw assembly to the front end face of the outer cylinder (6) and record the length value as B, measure the distance from the inner shoulder face of the coring drill bit (11) to the front end face of the outer cylinder (6) and record the length value as A, and the result obtained by subtracting the B value from the A value is the C value; Step C: adjusting the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit (11) through the axial adjustment component until the distance from the front end face of the core claw assembly to the inner shoulder surface of the coring drill bit (11) is equal to the C value.

4. The method for preventing core slippage by coring with directional horizontal holes for advanced exploration of coal mine faults according to claim 3 is characterized in that: When coring in soft formations: the C value is 6-11mm; when coring in hard formations: the C value is 11-16mm.

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