A coal mine underground directional long borehole deep hole fixed point pressure maintaining coring device

Abstract

This invention discloses a fixed-point pressure-maintaining coring device for deep directional long boreholes in coal mines. It mainly utilizes the sliding of a sliding column within the casing, and the top plate can dynamically adjust its radial position according to the actual diameter of the core. Even if the core has local irregularities, it can maintain uniform contact force, preventing the core from falling off or breaking during drilling. Furthermore, the rounded corners at the bottom of the top plate and the slightly larger diameter of the coring opening formed by the enclosure ensure that the core can smoothly enter the storage chamber, reducing entry resistance and mechanical damage, and protecting the integrity and original structure of the core, providing high-quality samples for subsequent geological analysis.

Description

Technical Field

[0001] This invention specifically relates to the field of coal mining technology, and more specifically to a device for fixed-point pressure-maintaining coring of deep holes in directional long boreholes in coal mines. Background Technology

[0002] In coal mine gas content determination and geological exploration, directional long-hole deep-hole coring technology is a key means to achieve accurate detection. A coring device typically includes a drill pipe, a coring mechanism, and a core-grabbing assembly. Its working principle is as follows: the drill pipe drives the coring mechanism to rotate and drill into the target formation. Under the action of drilling pressure and rotation, the core enters the reservoir cavity. The core is then held by the grabbing assembly and lifted to the surface with the drill string for subsequent gas content determination and geological analysis.

[0003] Existing core grasping methods mostly employ rigid clamp-type core claws or conical sleeve structures. During operation, these structures have a fixed clamping diameter, making dynamic adjustment impossible based on the actual core diameter. When the core diameter becomes irregular due to formation variations, localized fragmentation, or bedding development, the fixed-diameter grasping structure either clamps too tightly, causing surface cracking, scratches, or even localized breakage, thus damaging the core's original structure and bedding information.

[0004] In addition, insufficient clamping force may occur, and during the drilling process, the core may slip out of the storage chamber due to drill string vibration, fluid erosion in the borehole, or its own weight, resulting in core sampling failure. This rigid clamping method has an even lower success rate, especially in soft-hard interbedded or fractured soft coal seams, which seriously affects the recovery rate and sample representativeness of the core sampling operation. Summary of the Invention

[0005] Therefore, this invention proposes a directional long borehole deep hole fixed-point pressure-maintaining coring device for coal mines to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a device for fixed-point pressure-maintaining coring of deep directional long boreholes in coal mines, comprising:

[0007] The main rotating pipe is driven by the drilling drive equipment and rotates at high speed during drilling.

[0008] The coring mechanism is adapted to the main tube via an adapter. The coring mechanism can grasp the rock core of the target formation and store it under pressure.

[0009] A position sensor, which is installed on the coring mechanism, determines the target coring location by receiving instructions from the ground control system and identifying preset geological markers.

[0010] It also includes a control and communication module, which is integrated into the upper part of the main rotary pipe and interacts with the ground control system wirelessly to control the coring mechanism to move to the coring position and perform core drilling via a position sensor.

[0011] Optionally, a torque sensor is provided between the core-taking mechanism and the adapter.

[0012] Optionally, the core sampling mechanism includes:

[0013] The drill pipe has multiple core claw seats arranged in a circular array on its right end wall;

[0014] Guide ring, which is fixed to the inner wall of the drill pipe;

[0015] The pressure-holding coring assembly is movably installed inside the drill pipe;

[0016] A slip ring is fixedly connected to the pressure-holding core-taking assembly, and the slip ring is adaptably and slidably disposed within the guide ring;

[0017] And a guide post, which is fixed inside the left end of the drill pipe, wherein the guide post and the slip ring are axially slidably connected.

[0018] Optionally, the pressure-holding coring assembly includes:

[0019] The drill pipe has its left end sealed.

[0020] The sealing plate is fixed at the center of the drill pipe and divides the inner cavity of the drill pipe into an injection chamber and a storage chamber.

[0021] Multiple rock-grabbing components are arranged in a circumferential array on the cavity wall of the storage chamber;

[0022] And an airbag, which is compressed and arranged inside the right end of the drill pipe and abuts against the drill pipe, the airbag is inflated by an air supply system located in the air injection chamber and seals the right end of the drill pipe.

[0023] Optionally, the rock-gripping assembly includes:

[0024] The top plate adopts an arc-shaped plate structure coaxial with the drill pipe and is set inside the drill pipe;

[0025] The casing is fixedly embedded in the side wall of the drill pipe;

[0026] A sliding column is adapted to slide into the casing, and one end of the sliding column extends into the drill pipe and is then fixedly connected to the top plate.

[0027] A limiting block is fixedly connected to the other end of the sliding column;

[0028] And a second spring, which connects the top plate and the sleeve and is wound around the slide.

[0029] Optionally, under the elastic force of the second spring, the diameter of the core extraction port formed by the multiple top plate fences is slightly larger than the outer diameter of the drilled rock core, and the bottom corners of the top plate are all rounded.

[0030] Optionally, the air supply system consists of a booster pump and an extension pipe. The air inlet of the booster pump is connected to an external air supply device via an air pipe, and the air outlet of the booster pump is sealed to the air injection channel of the drilling pipe via an extension pipe. The air injection channel is also sealed to the airbag.

[0031] Optionally, a safety ring is fixedly fitted on the side wall of the left end of the drill pipe, and a buffer space is left between the safety ring and the annular step of the drill pipe.

[0032] Optionally, a first spring is connected between the drill pipe and the guide ring, and the first spring is wound around the side wall of the slip ring.

[0033] The present invention employs the above technology and has the following beneficial effects compared with the existing technology: The device of the present invention allows the top plate to dynamically adjust its radial position according to the actual diameter of the rock core by sliding the sliding column inside the casing. Even if there are local irregularities in the rock core, it can maintain uniform contact force, preventing the rock core from falling off or breaking during the drilling process. In addition, the rounded corners at the bottom of the top plate and the slightly larger diameter of the core extraction port formed by the fence ensure that the rock core can smoothly enter the storage cavity, reduce entry resistance and mechanical damage, protect the integrity and original structure of the rock core, and provide high-quality samples for subsequent geological analysis. Attached Figure Description

[0034] Figure 1 A schematic diagram of a directional long borehole deep hole fixed-point pressure-maintaining coring device for underground coal mines;

[0035] Figure 2 This is a schematic diagram of the internal structure of the coring mechanism in a directional long borehole deep hole fixed-point pressure-holding coring device for underground coal mines.

[0036] Figure 3 for Figure 2 An enlarged schematic diagram of part A in the middle;

[0037] Figure 4 for Figure 2 Enlarged schematic diagram of part B.

[0038] In the diagram: 1. Main tube; 2. Adapter; 3. Core sampling mechanism;

[0039] 301. Drill pipe; 302. Guide column; 303. First spring; 304. Sealing plate; 305. Airbag; 306. Core claw seat; 307. Drilling pipe; 308. Safety ring; 309. Slip ring; 310. Guide ring; 311. Extension pipe; 312. Air injection channel; 313. Booster pump; 314. Top plate; 315. Second spring; 316. Slip column; 317. Casing; 318. Limiting block. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example: Please refer to the appendix. Figure 1-4 This invention provides a technical solution: a device for fixed-point pressure-maintaining coring of deep directional long boreholes in coal mines, comprising:

[0042] The main rotating pipe 1 is driven by the drilling drive equipment and rotates at high speed during drilling.

[0043] The core sampling mechanism 3 is adapted to the main tube 1 via the adapter 2. The core sampling mechanism 3 can grab the rock core of the target stratum and store it under pressure.

[0044] Position sensor 41 is installed on the coring mechanism 3. Position sensor 41 determines the target coring location by receiving instructions from the ground control system and identifying preset geological markers.

[0045] And the control and communication module 5, which is integrated on the upper part of the main rotary pipe 1, and interacts with the ground control system wirelessly to control the core sampling mechanism 3 to move to the core sampling position and perform core drilling through the position sensor 41.

[0046] It should be added that the location sensor can be a high-precision ground-penetrating radar, which can capture geological feature parameters in the borehole in real time, such as rock density and magnetic anomalies, and compare these parameters with a preset geological marker database to accurately locate the target core layer.

[0047] In this embodiment, a torque sensor is provided between the core sampling mechanism 3 and the adapter 2. The torque sensor can monitor the torque changes that the core sampling mechanism bears during drilling in real time and feed the data back to the control and communication module. When the torque exceeds the preset threshold or abnormal fluctuations occur, the system can automatically adjust the drilling speed or stop drilling, effectively preventing equipment overload or damage caused by hard rock layers, foreign objects stuck, etc.

[0048] Meanwhile, torque data can also help determine the properties of rock strata, providing real-time data support for coring operations and enhancing the device's adaptability to complex geological conditions.

[0049] In this embodiment, the core extraction mechanism 3 includes:

[0050] The drill pipe 301 has multiple core claw seats 306 arranged in a circular array on its right end wall;

[0051] The guide ring 310 is fixed to the inner wall of the drill pipe 301;

[0052] The pressure-holding coring assembly is movably installed inside the drill pipe 310;

[0053] The slip ring 309 is fixedly connected to the pressure-holding core-taking assembly, and the slip ring 309 can be adapted to slide within the guide ring 310;

[0054] And guide post 302, which is fixed inside the left end of drill pipe 301, and guide post 302 and slip ring 309 are axially slidably connected.

[0055] In this embodiment, the pressure-holding core sampling assembly includes:

[0056] The drill pipe 307 has its left end sealed.

[0057] The sealing plate 304 is fixed at the center of the drill pipe 307 and divides the inner cavity of the drill pipe 307 into an injection chamber and a storage chamber.

[0058] Multiple rock-grabbing components are arranged in a circumferential array on the cavity wall of the storage chamber;

[0059] And an airbag 305, which is compressed and arranged inside the right end of the drill pipe 301 and abuts against the drill pipe 307. The airbag 305 is inflated by an air supply system located in the air injection chamber and seals the right end of the drill pipe 301.

[0060] In this embodiment, the rock-gripping component includes:

[0061] The top plate 314 adopts an arc-shaped plate structure coaxial with the drill pipe 307 and is set inside the drill pipe 307;

[0062] The casing 317 is fixedly embedded in the side wall of the drill pipe 307;

[0063] The sliding column 316 is adapted to slide and connect with the casing 317, and one end of the sliding column 317 extends into the drill pipe 307 and is then fixedly connected to the top plate 314.

[0064] The limiting block 318 is fixedly connected to the other end of the sliding column 316;

[0065] And a second spring 315, which is connected between the top plate 314 and the sleeve 317 and is wound around the slide 316.

[0066] In this embodiment, under the elastic force of the second spring 315, the diameter of the core extraction port formed by the multiple top plates 314 is slightly larger than the outer diameter of the drilled core, allowing the core to enter the storage chamber smoothly. Furthermore, the bottom corners of the top plates 314 are rounded, which further reduces the resistance and damage to the core during entry.

[0067] It should be noted that by sliding the sliding column inside the casing, the top plate can dynamically adjust its radial position according to the actual diameter of the core. Even if there are local irregularities in the core, it can maintain uniform contact force, preventing the core from falling off or breaking during the drilling process. In addition, the rounded corners at the bottom of the top plate and the slightly larger diameter of the core extraction port formed by the fence ensure that the core can smoothly enter the storage chamber, reduce entry resistance and mechanical damage, and protect the integrity and original structure of the core, providing high-quality samples for subsequent geological analysis.

[0068] In this embodiment, the air supply system consists of a booster air pump 313 and an extension pipe 311. The air inlet of the booster air pump 313 is connected to an external air supply device via an air pipe, and the air outlet of the booster air pump 313 is sealed to the air injection channel 312 of the drilling pipe 301 via the extension pipe 311. The air injection channel 312 is also sealed to the airbag 305.

[0069] It should be noted that after coring is completed, ground commands drive the booster pump to inject air into the airbag. The airbag expands within seconds and seals the right end of the drill pipe. The sealing action is faster than that of mechanical structures, effectively reducing the time for gas to escape.

[0070] In this embodiment, a safety ring 308 is fixedly fitted on the side wall of the left end of the drill pipe 307, and the safety ring 308 and the annular step of the drill pipe 301 have a buffer space.

[0071] In this embodiment, a first spring 303 is connected between the drill pipe 307 and the guide ring 310, and the first spring 303 is wound around the side wall of the slip ring 309.

[0072] In practical implementation, after the drill bit completes drilling to the specified depth, the drill bit is removed and the core sampling mechanism 3 in the device of this invention is replaced. The ground control system sends a start command to the core sampling device through the control and communication module. The main rotary pipe 1 starts to rotate at high speed under the drive of the drilling drive equipment, and drives the core sampling mechanism 3 to rotate synchronously. During the descent, the position sensor receives the command from the ground control system in real time and identifies the preset geological markers. When it is determined that the target core sampling position has been reached, the drilling drive equipment is controlled to adjust the drilling state and prepare for core drilling.

[0073] During the drilling process, the torque sensor monitors the torque received by the core sampling mechanism 3 in real time. When the torque reaches the preset threshold or abnormal fluctuations occur, it can be fed back to the control and communication module 5 in a timely manner so that the ground control system can make corresponding adjustments to prevent equipment overload or drilling abnormalities.

[0074] Furthermore, the core sampling process is as follows: The core claw seat 306 at the right end of the drill pipe 301 first contacts and drills into the target formation. Under the action of the drilling force, the core gradually enters the storage cavity of the drill pipe 307. At this time, due to the entry of the core, the top plate 314 in the multiple circumferential array of rock-grabbing components is squeezed by the core and moves towards the inner wall of the drill pipe 307. The top plate 314 drives the sliding column 316 fixedly connected to it to slide in the casing 317. Through the elastic force of the second spring 315, the top plate 314 is tightly attached to the surface of the core, forming a flexible gripping of the core.

[0075] After core drilling is completed, the control and communication module controls the gas supply system to start. The booster pump 313 obtains gas from the external gas supply equipment through the gas pipe connected to the gas inlet end. After being pressurized, the gas is delivered to the gas injection channel 312 of the drilling pipe 301 through the extension pipe 311 at the gas outlet end, and then enters the air bag 305. The air bag 305 begins to expand under the action of the gas and gradually seals the right end of the drilling pipe 301, thereby achieving a pressure-maintaining environment for the core in the storage cavity.

[0076] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for fixed-point pressure-holding coring of deep, directional long boreholes in coal mines, characterized in that, It includes: The main rotating pipe (1) is driven by the drilling drive equipment and rotates at high speed during drilling. The core sampling mechanism (3) is adapted to the main tube (1) via an adapter (2). The core sampling mechanism (3) can grab the core of the target stratum and store it under pressure. A position sensor (41) is installed on the coring mechanism (3). The position sensor (41) determines the target coring location by receiving instructions from the ground control system and identifying preset geological markers. And a control and communication module (5), which is integrated on the upper part of the main rotary pipe (1) and interacts with the ground control system wirelessly to control the core sampling mechanism (3) to move to the core sampling position and perform core drilling through the position sensor (41).

2. The device for fixed-point pressure-maintaining coring of deep directional long boreholes in coal mines according to claim 1, characterized in that: A torque sensor is provided between the core extraction mechanism (3) and the adapter (2).

3. The device for fixed-point pressure-maintaining coring of deep directional long boreholes in coal mines according to claim 2, characterized in that: The core extraction mechanism (3) includes: The drill pipe (301) has multiple core claw seats (306) arranged in a circular array on its right end wall. A guide ring (310) is fixed to the inner wall of the drill pipe (301); The pressure-holding coring assembly is movably installed inside the drill pipe (310); A slip ring (309) is fixedly connected to the pressure-holding core-taking assembly, and the slip ring (309) can be adapted to slide within the guide ring (310); And a guide post (302), which is fixed inside the left end of the drill pipe (301), wherein the guide post (302) and the slip ring (309) are axially slidably connected.

4. The device for fixed-point pressure-maintaining coring of deep directional long boreholes in coal mines according to claim 3, characterized in that: The pressure-holding coring assembly includes: The drill pipe (307) has its left end sealed. The sealing plate (304) is fixed at the center of the drill pipe (307) and divides the inner cavity of the drill pipe (307) into an injection chamber and a storage chamber. Multiple rock-grabbing components are arranged in a circumferential array on the cavity wall of the storage chamber; And an airbag (305), which is compressed and arranged in the right end of the drill pipe (301) and abuts against the drill pipe (307), the airbag (305) is inflated by an air supply system located in the air injection chamber and blocks the right end of the drill pipe (301).

5. A device for fixed-point pressure-maintaining coring of deep directional long boreholes in coal mines according to claim 4, characterized in that: The rock-gripping component includes: The top plate (314) adopts an arc-shaped plate structure coaxial with the drill pipe (307) and is set inside the drill pipe (307); The casing (317) is fixedly embedded in the side wall of the drill pipe (307); A sliding column (316) is adapted to slide into the casing (317), and one end of the sliding column (317) extends into the drill pipe (307) and is then fixedly connected to the top plate (314); The limiting block (318) is fixedly connected to the other end of the sliding column (316); And a second spring (315), which is connected between the top plate (314) and the sleeve (317) and wound around the slide (316).

6. A device for fixed-point pressure-maintaining coring of deep directional long boreholes in coal mines according to claim 5, characterized in that: Under the elastic force of the second spring (315), the diameter of the core extraction port formed by the multiple top plates (314) is slightly larger than the outer diameter of the drilled rock core, and the bottom corners of the top plates (314) are all rounded.

7. A device for fixed-point pressure-holding coring of deep directional long boreholes in coal mines according to claim 4, characterized in that: The air supply system consists of a booster pump (313) and an extension pipe (311). The air inlet of the booster pump (313) is connected to an external air supply device via an air pipe. The air outlet of the booster pump (313) is sealed to the air injection channel (312) of the drilling pipe (301) via the extension pipe (311). The air injection channel (312) is sealed to the air bag (305).

8. A device for fixed-point pressure-maintaining coring of deep directional long boreholes in coal mines according to claim 4, characterized in that: A safety ring (308) is fixedly fitted on the side wall of the left end of the drill pipe (307), and the safety ring (308) and the annular step of the drill pipe (301) have a buffer space.

9. A device for fixed-point pressure-maintaining coring of deep directional long boreholes in coal mines according to claim 4, characterized in that: A first spring (303) is connected between the drill pipe (307) and the guide ring (310), and the first spring (303) is wound around the side wall of the slip ring (309).

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