Directional long drilling and fixed-point hydraulic cave-making punching device for low-permeability coal seam

Abstract

The invention discloses a low-permeability coal seam directional long drill hole fixed-point hydraulic cave-making punching device which comprises a drill pipe driven by well drilling driving equipment to directionally drill into a specified drill hole; the self-driven drill bit is mounted on the drilling end part of the drill pipe; the number of the expansion joints is two, the expansion joints are symmetrically fixed to the drill pipe, and liquid injection pressurization is conducted on each expansion joint through first liquid supply equipment, so that the expansion joints are expanded, and a designated section of a drill hole is packed. A jet flow adjusting mechanism is arranged in the device, a flow control disc is driven by a motor to rotate, and when a through opening of the flow control disc is aligned with a liquid flowing channel, liquid passes through the flow control disc; when the solid part of the flow control disc blocks the flow channel, the liquid is cut off, so that the jet flow adjusting mechanism has an intermittent jet flow mode and a continuous jet flow mode, the jet flow adjusting mechanism can be rapidly switched among a plurality of jet flow punching pieces or among different punching modes under the condition that the main pumping pressure is not changed, and the operation process is smoother.

Description

Technical Field

[0001] This invention specifically relates to the field of coal mine borehole pressure injection and permeability enhancement technology, and more specifically to a device for directional long borehole fixed-point hydraulic cavity creation and punching in low-permeability coal seams. Background Technology

[0002] Coal seam gas control is a crucial aspect of ensuring safe coal mine production. Among these measures, hydraulic permeability enhancement technology is a core method for improving the gas extraction efficiency of low-permeability coal seams. Hydraulic perforation technology uses high-pressure water jets to cut and break up the coal seam within boreholes, creating a network of cavities and fractures, thereby expanding the gas desorption range and opening up gas flow channels.

[0003] Currently, the most widely used technology in this field is point-to-point hydraulic fracturing or hydraulic perforation, which typically includes drill pipe, packer and jet nozzle, and high-pressure water jetting is carried out after a specific section of the borehole is sealed.

[0004] However, due to the complex geological conditions of coal seams, the requirements for jet characteristics differ at different perforation stages (such as initial perforation, hole enlargement and cavity creation, fracture extension, and water injection for enhanced permeability). The initial stage requires strong rock breaking, while the enhanced permeability stage requires disturbing the fracture network. Existing technologies lack the ability to dynamically adjust the jet state during operation, and cannot flexibly switch between "high-intensity impact" and "deep penetration" modes according to real-time operating conditions, thus limiting the overall effect of a single operation. Summary of the Invention

[0005] Therefore, this invention proposes a directional long borehole fixed-point hydraulic cavity punching device for low-permeability coal seams 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 directional long borehole drilling and fixed-point hydraulic cavity creation and punching in low-permeability coal seams, comprising:

[0007] Drill pipe, which is driven by drilling drive equipment to be directionally drilled into a designated borehole;

[0008] A self-driving drill bit, which is mounted on the drilling end of the drill string;

[0009] There are two expansion joints, which are symmetrically fixed on the drill pipe. Each expansion joint is injected and pressurized by the first fluid supply device, so that the expansion joint expands and seals a designated section of the borehole.

[0010] And jet punching components, which are provided in multiples and installed in a circumferential array on the side of the drill pipe, with each jet punching component located between two expansion joints;

[0011] Each of the jet punching components is connected to a second liquid supply device via a high-pressure pipeline to perform punching and water injection permeation operations on the drilled section located between the two expansion joints.

[0012] Optionally, the jet punching component includes:

[0013] The base is fixedly embedded in the side of the drill pipe and communicates with the inner cavity of the drill pipe;

[0014] The main housing is fixed to the base by a locking ring. A liquid flow channel is provided inside the main housing, and a rubber tube connects the liquid flow channel to the liquid injection chamber of the base.

[0015] The jet flow adjustment mechanism is installed inside the main housing and can control the intermittent or continuous flow state of the liquid flow channel inside the main housing.

[0016] The booster flow seat is sealed and fixed at the outlet end of the main housing;

[0017] And the jet nozzle, which is sealed and fixed on the pressurized flow seat.

[0018] Optionally, a piston is slidably disposed in the injection chamber of the base. The piston is fixedly connected to one end of a slide rod, and the other end of the slide rod passes through the base and the cylindrical shell fixed on the base, and is then fixedly connected to a stop block.

[0019] A first spring is provided inside the cylindrical shell. The first spring is wound around the side wall of the slide rod, and the right end of the first spring is fixed to the slide rod.

[0020] Optionally, under the elastic force of the first spring, the piston blocks the liquid inlet of the base, and the piston is located on the right side of the tubing.

[0021] Optionally, the jet adjustment mechanism includes:

[0022] A flow control plate is fitted and rotatably disposed in a flow-blocking cavity within the main housing, and an external toothed ring is provided on the side wall of the flow control plate;

[0023] The drive gear is driven by an electric motor;

[0024] And the linkage gear, which is connected between the drive gear and the external gear ring.

[0025] Optionally, the flow control plate has a through-hole at its eccentric part, and the through-hole can be connected to the flow channel.

[0026] Optionally, the jet nozzle includes:

[0027] The spray nozzle is sealed and fixed on the pressurized flow seat;

[0028] A sealing ring, which is fixed inside the spray nozzle;

[0029] The jet nozzle has its right end fitted and sliding into the sealing ring;

[0030] And a second spring, which is located inside the spray holder and connected between the left end of the jet nozzle and the sealing ring.

[0031] Optionally, under the elastic force of the second spring, the left end of the jet nozzle can extend out from the nozzle holder.

[0032] Optionally, a support plate is fixed inside the pressure boosting seat, and multiple uniformly distributed pressure equalizing and diverting pipes are fixed on the support plate, wherein the diameter of the right end of the pressure equalizing and diverting pipe is larger than the diameter of its left end.

[0033] The present invention employs the above technology and has the following beneficial effects compared with existing technologies:

[0034] The device of this invention is equipped with a jet regulating mechanism, which drives the flow control plate to rotate via a motor. When the opening of the flow control plate is aligned with the liquid flow channel, the liquid flows through; when the solid part of the flow control plate blocks the flow channel, the liquid is cut off. Therefore, the jet regulating mechanism has two modes: intermittent jetting and continuous jetting.

[0035] 1. Intermittent pulse jet: The high-pressure water jet generated in this mode is pulsed, which has a stronger impact dynamic load effect on the coal body, and has higher rock breaking and cavity creation efficiency. The pulse pressure wave can also produce fatigue effect in the coal seam fracture, which is more conducive to expanding and extending the fracture network. It can also be used to clean and flush the hole wall after cavity creation or to carry out stable water injection to enhance permeability.

[0036] 2. Continuous pulse jet: mainly used in the initial punching stage and water injection permeability enhancement stage, the continuous pulse impact causes the coal and rock fractures to open and close periodically, the stress at the fracture tip is highly concentrated, resulting in rapid expansion and penetration of the fracture. Attached Figure Description

[0037] Figure 1 A schematic diagram of a hydraulic cavity-forming and punching device for directional long boreholes in low-permeability coal seams.

[0038] Figure 2 A partially enlarged schematic diagram of a hydraulic cavity-forming and punching device for directional long boreholes in low-permeability coal seams;

[0039] Figure 3 for Figure 2 Schematic diagram of the internal structure of a jet punched component;

[0040] Figure 4 for Figure 3 Schematic diagram of the connection between the base and the main housing;

[0041] Figure 5 for Figure 3 Schematic diagram of the internal structure of the booster flow seat;

[0042] Figure 6 for Figure 5 An enlarged schematic diagram of part A in the middle.

[0043] In the diagram: 1. Drill pipe; 2. Expansion joint; 3. Jet punching component;

[0044] 301. Flow control plate; 302. Linkage gear; 303. Drive gear; 304. Motor; 305. Flow channel; 306. Main housing; 307. Block; 308. First spring; 309. Locking ring; 310. Piston; 311. Base; 312. Injection chamber; 313. Pressure equalizing and diverting pipe; 314. Pressure boosting flow seat;

[0045] 3071, Spray mount; 3072, Jet nozzle; 3073, Second spring; 3074, Sealing ring. Detailed Implementation

[0046] 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.

[0047] Example: Please refer to the appendix Figure 1-6 This invention provides a technical solution: a hydraulic cavity-forming and punching device for directional long drilling in low-permeability coal seams, comprising:

[0048] Drill pipe 1, which is driven by drilling drive equipment to be directionally drilled into the designated borehole;

[0049] A self-driven drill bit is mounted on the drilling end of drill pipe 1;

[0050] There are two expansion joints 2, which are symmetrically fixed on the drill pipe 4. Each expansion joint 2 is injected and pressurized by the first liquid supply device, so that the expansion joint 2 expands and seals a designated section of the borehole.

[0051] Specifically, by using two symmetrically arranged expansion joints, a closed working chamber can be formed in any designated section of a long borehole. This strictly limits the effect of the high-pressure water jet to the target section between the two expansion joints, avoiding ineffective energy loss and achieving "targeted" treatment of low-permeability coal seams, accurately targeting gas-rich areas or low-permeability areas.

[0052] And jet punching parts 3, which are provided in multiples and are installed in a circumferential array on the side of the drill pipe 1, and each jet punching part 3 is located between two expansion joints 2.

[0053] Each jet punch 3 is connected to the second liquid supply device through a high-pressure pipeline to perform punching and water injection to enhance the permeability of the drilled section located between the two expansion joints 2.

[0054] In this embodiment, the jet punching component 3 includes:

[0055] The base 311 is fixedly embedded in the side of the drill pipe 1 and communicates with the inner cavity of the drill pipe 1.

[0056] The main housing 306 is fixed to the base 311 by a locking ring 309. The main housing 306 is provided with a liquid flow channel 305, and a rubber tube is connected between the liquid flow channel 305 and the liquid injection chamber 312 of the base 311.

[0057] The jet flow adjustment mechanism is installed inside the main housing 306 and can control the intermittent or continuous flow state of the flow channel 305 inside the main housing 306.

[0058] The booster flow seat 314 is sealed and fixed at the outlet end of the main housing 306;

[0059] And the jet nozzle, which is sealed and fixed on the pressurized flow seat 314.

[0060] In this embodiment, a piston 310 is slidably disposed in the injection chamber 312 of the base 311. The piston 310 is fixedly connected to one end of the slide rod, and the other end of the slide rod passes through the base 311 and the cylindrical shell fixed on the base 311, and is then fixedly connected to the block 307.

[0061] A first spring 308 is provided inside the cylinder shell. The first spring 308 is wound around the side wall of the slide rod, and the right end of the first spring 308 is fixed to the slide rod.

[0062] In this embodiment, under the elastic force of the first spring 308, the piston 310 is blocked at the liquid inlet of the base 311, and the piston 310 is located on the right side of the tube.

[0063] In this embodiment, the jet adjustment mechanism includes:

[0064] The flow control plate 301 is fitted and rotatably disposed in the flow-blocking cavity inside the main housing 306, and an external toothed ring is provided on the side wall of the flow control plate 301.

[0065] The drive gear 303 is driven by the motor 304;

[0066] And the linkage gear 302, which is connected between the drive gear 303 and the external gear ring.

[0067] In this embodiment, the eccentric part of the flow control plate 301 is provided with a through-hole, and the through-hole can be connected to the flow channel 305.

[0068] It should be noted that the flow control plate is rotated by a motor. When its opening is aligned with the flow channel, the liquid flows through (opening); when the solid part of the flow control plate blocks the flow channel, the liquid is cut off (closing). Therefore, the jet adjustment mechanism has two modes: intermittent jet and continuous jet.

[0069] 1. Intermittent pulse jet: The high-pressure water jet generated in this mode is pulsed, which has a stronger impact dynamic load effect on the coal body, and has higher rock breaking and cavity creation efficiency. The pulse pressure wave can also produce fatigue effect in the coal seam fracture, which is more conducive to expanding and extending the fracture network. It can also be used to clean and flush the hole wall after cavity creation or to carry out stable water injection to enhance permeability.

[0070] 2. Continuous pulse jet: mainly used in the initial punching stage and water injection permeability enhancement stage, the continuous pulse impact causes the coal and rock fractures to open and close periodically, the stress at the fracture tip is highly concentrated, resulting in rapid expansion and penetration of the fracture;

[0071] Therefore, it can be seen that the jet adjustment mechanism can quickly switch between multiple jet punching parts or different punching modes without changing the main pump pressure, making the operation process smoother.

[0072] In this embodiment, the jet nozzle includes:

[0073] Spray holder 3071, which is sealed and fixed on pressurized flow holder 314;

[0074] The sealing ring 3074 is fixed inside the spray base 3071;

[0075] The jet nozzle 3072 has its right end fitted and slidably attached to the sealing ring.

[0076] And a second spring 3073, which is disposed in the spray base 3071 and connected between the left end of the jet nozzle 3072 and the sealing ring 3074.

[0077] In this embodiment, under the elastic force of the second spring 3073, the left end of the jet nozzle 3072 can extend out from the spray base 3071.

[0078] It should be noted that, under the action of the second spring, the jet nozzle extends to the left when not in operation. When high-pressure fluid is introduced, the reverse action of the hydraulic force can overcome the spring force and push the nozzle back into the spray seat to the right to start jetting. When the fluid supply is stopped, the spring pushes the nozzle back. This reciprocating motion can shear and remove coal dust and impurities that may be stuck in the nozzle orifice, effectively preventing blockage.

[0079] In this embodiment, a support plate is fixed inside the pressure boosting seat 314, and multiple uniformly distributed pressure equalizing and diverting pipes 313 are fixed on the support plate, and the diameter of the right end of the pressure equalizing and diverting pipe 313 is larger than the diameter of its left end.

[0080] 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 low permeability coal seam directional long borehole fixed-point hydraulic cavitation punching device, characterized in that, It includes: A drill pipe (1) is driven by a drilling driving device to direct drill into a specified borehole; A self-driven drill bit is installed on the drilling end of the drill pipe (1); Expansion joints (2) are provided with two and are symmetrically fixed on the drill pipe (4), each of the expansion joints (2) is pressurized by a first liquid supply device to expand the expansion joint (2) and seal the specified section of the borehole; And a jet puncher (3) is provided with a plurality of and is circumferentially arrayed on the side of the drill pipe (1), and each jet puncher (3) is located between two expansion joints (2); Wherein, each of the jet puncher (3) is connected with a second liquid supply device through a high-pressure pipeline to punch and water-flood the section of the borehole between the two expansion joints (2).

2. The low-permeability coal seam directional long borehole fixed-point hydraulic cavitation punching device according to claim 1, characterized in that: The jet puncher (3) includes: A base (311) is fixedly embedded on the side of the drill pipe (1) and communicates with the inner cavity of the drill pipe (1); A main shell (306) is fixed on the base (311) by a lock ring (309), a liquid flow channel (305) is arranged in the main shell (306), and a rubber tube is communicated between the liquid flow channel (305) and the liquid injection cavity (312) of the base (311); A jet adjusting mechanism is installed in the main shell (306) and can control the intermittent or continuous liquid flow state of the liquid flow channel (305) in the main shell (306); A pressurized flow seat (314) is sealingly fixed on the outlet end of the main shell (306); And a jet nozzle is sealingly fixed on the pressurized flow seat (314).

3. The low-permeability coal seam directional long borehole fixed-point hydraulic cavitation punching device according to claim 2, characterized in that: A piston (310) is slidably arranged in the liquid injection cavity (312) of the base (311), one end of the piston (310) is fixedly connected with a slide rod, the other end of the slide rod penetrates the base (311) and a barrel shell fixed on the base (311), and then is fixedly connected with a stop block (307); A first spring (308) is arranged in the barrel shell, the first spring (308) is wound on the side wall of the slide rod, and the right end of the first spring (308) is fixed on the slide rod.

4. The low-permeability coal seam directional long borehole fixed-point hydraulic cavitation punching device according to claim 3, characterized in that: Under the elastic force of the first spring (308), the piston (310) blocks the liquid inlet of the base (311), and the piston (310) is located on the right side of the rubber tube.

5. The low permeability coal seam directional long borehole spot hydraulic cavitation punching device according to claim 2, characterized in that: The jet adjusting mechanism includes: A flow control disc (301) is rotatably arranged in a flow blocking cavity in the main shell (306), an outer gear ring is arranged on the side wall of the flow control disc (301); A driving gear (303) is driven by a motor (304); And a linkage gear (302) is drivingly connected between the driving gear (303) and the outer gear ring.

6. The low-permeability coalbed directional long-hole spot hydraulic cavitation punching device according to claim 5, characterized in that: An eccentric through hole is arranged in the flow control disc (301), and the through hole can communicate with the liquid flow channel (305).

7. The low permeability coal seam directional long borehole spot hydraulic cavitation punching device according to claim 2, characterized in that: The jet nozzle includes: A nozzle seat (3071) is sealingly fixed on the pressurized flow seat (314); A sealing ring (3074) is fixed in the nozzle seat (3071); A jet nozzle (3072) is right end abutting and slidingly connected in the sealing ring; A second spring (3073) is arranged in the nozzle seat (3071) and connected between the left end of the jet nozzle (3072) and the sealing ring (3074).

8. The low-permeability coalbed directional long-hole spot hydraulic cavitation punching device according to claim 7, characterized in that: Under the elastic force of the second spring (3073), the left end of the jet nozzle (3072) can extend out of the nozzle seat (3071).

9. The low-permeability coalbed directional long-hole spot hydraulic cavitation punching device according to claim 2, characterized in that: A support disc is fixed in the pressurized flow seat (314), a plurality of uniformly distributed pressure distribution shunt pipes (313) are fixed on the support disc, and the caliber of the right end of the pressure distribution shunt pipe (313) is greater than that of the left end.

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