Device for coal seam gas pre-extraction drilling construction

Abstract

The utility model discloses a device for coal seam gas pre-extraction drilling construction, which comprises a pilot drill bit (2), a mechanical reaming cutter (3), a sealing drill rod (4), a sealing rotary joint (5), a hydraulic directional drilling machine (6) and a water pump (7), the pilot drill bit (2) is in threaded connection with the mechanical reaming cutter (3), one end of the sealing drill rod (4) is connected with the mechanical reaming cutter (3), and the other end of the sealing drill rod (4) is connected with a driving drill rod (17). The driving drill rod (17) is fixed on a chuck of the hydraulic directional drilling machine (6), a water inlet hose of the water pump (7) is connected with the water tank (8), a water outlet hose of the water pump (7) is communicated with the sealing rotary joint (5), and the sealing rotary joint (5) is in threaded connection with the driving drill rod (17). The method has the advantages that the engineering construction cost can be reduced, and the construction efficiency and the drilling quality are improved; and moreover, the drilling power is increased, the diameter and depth of the drill hole can meet the use requirements, and the gas pre-extraction time is shortened.

Description

TECHNICAL FIELD

[0001] The utility model relates to a device for underground coal seam gas pre-drainage drilling construction, which solves the problems of difficult drilling construction and long construction time of gas drainage drilling in underground high-gas soft coal seam through drilling, reaming and punching simultaneous construction. BACKGROUND

[0002] With the increase of coal mining depth year by year, the underground coal seam in China faces complex geological conditions of high stress, high gas and low permeability, which brings a series of technical problems to the efficient, green and safe mining of underground coal.

[0003] Coal seam gas pre-drainage not only can effectively solve the problem of gas overrun, but also can play a role in pressure relief, reducing the probability of coal and gas outburst, rock burst and other accidents. Therefore, how to improve the gas pre-drainage efficiency and concentration of underground high-gas soft outburst coal seam, reduce gas drainage attenuation and pre-drainage standard time, and ensure the efficient connection of underground coal seam gas drainage-mining-mining, has become one of the important factors affecting the safe and efficient mining of coal mines.

[0004] At present, the coal seam gas pre-drainage drilling construction is mainly completed by using ordinary hydraulic drilling machine and special-shaped drill rod. The machine is not convenient to move underground, the drilling machine has small power, the hole depth is shallow, and there is no high-pressure pump for continuous cleaning of the drilling hole, which leads to difficult deslagging during drilling, low drilling quality, and further affects the gas drainage efficiency and drainage volume. At the same time, the strength of various special-shaped drill rods such as three-prong drill rod and grooved drill rod is not high, the sealing performance is not good, the drilling hole wall is disturbed greatly during drilling, which indirectly increases the drilling resistance, aggravates the problem of insufficient drilling power of ordinary drilling machine, and makes it difficult to reach the design requirements of drilling diameter and drilling depth, and further cannot achieve the goal of efficient drainage of coal seam gas. TECHNICAL FIELD

[0005] In view of the problems existing in the prior art, the technical problem to be solved by the utility model is to provide a device for coal seam gas pre-drainage drilling construction, which can reduce engineering construction cost, improve construction efficiency and drilling quality, increase drilling power, ensure drilling diameter and drilling depth, and shorten gas pre-drainage time.

[0006] In order to solve the above technical problems, the technical scheme of the utility model is:

[0007] The utility model provides a device for coal seam gas pre -extraction drilling construction, including pilot drill bit, mechanical reamer, sealing drill rod, sealing swivel, hydraulic directional drilling machine, water pump and water tank, pilot drill bit and mechanical reamer are connected through screw thread, sealing drill rod one end is connected with mechanical reamer, the other end is connected with driving drill rod, and driving drill rod is fixed on the chuck of hydraulic directional drilling machine, and the inlet hose of water pump is connected with water tank, and the outlet hose of water pump is connected with sealing swivel, sealing swivel and driving drill rod are connected through screw thread.

[0008] Preferably, a vibrating screen type mud remover is arranged at the drilling hole opening of the coal rock stratum, and the filtered backflow water of the vibrating screen type mud remover reenters the water tank.

[0009] The utility model has the advantages that:

[0010] The utility model contains pilot drill bit, mechanical reamer and water pump, realizes drilling - reaming - punching simultaneous construction, increases the gas desorption area and desorption volume in gas extraction drilling hole after reaming, shortens drilling construction time, reduces engineering construction cost. The drilling - reaming - punching integrated construction mode avoids frequent tripping process, reduces the disturbance of drilling tool to the hole wall during drilling process, thereby improving the hole wall quality. BRIEF DESCRIPTION OF DRAWINGS

[0011] The drawings of the utility model are as follows:

[0012] Figure 1 It is the combined structure diagram of the utility model;

[0013] Figure 2 It is the structural schematic diagram of sealing drill rod;

[0014] Figure 3 It is the structural schematic diagram of sealing swivel.

[0015] In the drawing, 1, coal rock stratum; 2, pilot drill bit; 3, mechanical reamer; 4, sealing drill rod; 5, sealing swivel; 6, hydraulic directional drilling machine; 7, water pump; 8, water tank; 9, vibrating screen type mud remover; 10, sealing drill rod hollow rod; 11, outer spiral blade; 12, sealing joint; 13, joint body thread section; 14, joint body; 15, Y type sealing ring; 16, rotating sliding sleeve; 17, driving drill rod. DETAILED DESCRIPTION

[0016] The utility model will be further described below in connection with the drawings and examples, but the protection scope of the utility model is not limited to this:

[0017] As Figure 1 shown, the utility model includes pilot drill bit 2, mechanical reamer 3, sealed drill rod 4, sealed rotary joint 5, hydraulic directional drilling machine 6, water pump 7 and water tank 8, pilot drill bit 2 is connected through the thread with mechanical reamer 3, one end of sealed drill rod 4 is connected with mechanical reamer 3, the other end is connected with driving drill rod 17, driving drill rod 17 is fixed on chuck of hydraulic directional drilling machine 6, inlet hose of water pump 7 is connected with water tank 8, outlet hose of water pump 7 is connected with sealed rotary joint 5, sealed rotary joint 5 is connected through the thread with driving drill rod 17.

[0018] Vibrating screen type mud remover 9 is placed at the drilling hole mouth of coal rock layer 1, vibrating screen type mud remover 9 separates coal cinder from water, coal cinder is cleaned out of drilling field periodically, and filtered backflow water enters water tank 8 again, so that the repeated use of clean water is realized.

[0019] Pilot drill bit 2 is three-wing center hole type drill bit, and the diameter of drill bit is Φ113mm, which is used for breaking coal rock and drilling out coal cinder, and pilot drill bit 2 is provided with a center hole to guarantee the flushing of drilling hole by drilling fluid, so as to flush and discharge coal cinder.

[0020] As Figure 2 shown, sealed drill rod 4 is composed of sealed drill rod hollow rod 10, outer spiral blade 11 and sealing joint 12, the outer diameter of sealed drill rod hollow rod 10 is 73mm, the inner diameter is 60mm, and the length is 1500mm. The outer spiral blade is wound on the outer periphery of sealed drill rod hollow rod 10, and has a thickness of 8mm, a width of 20mm, a helical angle of 20°, a helical pitch of 200mm and a helical groove design depth of 10mm, which is convenient for quickly discharging coal cinder. Sealing joint 12 is a conical thread sealing joint, which is arranged at both ends of sealed drill rod hollow rod 10, has a thread taper of 8°, a thread segment length of 48mm, and two rectangular thread grooves are arranged in the end of thread, with a groove depth of 1.7mm, and O-shaped sealing ring is used to realize static sealing. Sealed drill rod 4 is connected with driving drill rod 17, and the outer wall of driving drill rod 17 is locked and deadlocked by the slip on the drilling machine, and power is transmitted.

[0021] Sealed drill rod 4 is made of high-strength geological alloy steel material, and is processed by one-time forming type processing strengthening treatment, the tensile strength of sealed drill rod hollow rod is more than 950MPa, the torsional strength is greater than 15000N.m, and the sealing pressure-bearing capacity is more than 100MPa, so as to avoid accidents such as fracture and leakage of drill rod in the mechanical reaming process. The sealing joint 12 at one end of sealed drill rod 4 is threadedly connected with mechanical reamer 3, and the sealing joint 12 at the other end is threadedly connected with driving drill rod 17.

[0022] As Figure 3As shown, the sealing rotary joint 5 comprises a joint body 14, a Y-shaped sealing ring 15 and a rotary sleeve 16. The joint body 14 is connected to the water outlet hose of the water pump 7 through the threaded segment 13. The rotary sleeve 16 is sleeved on the other end of the threaded segment of the joint body 14. Two sealing grooves are arranged on the contact surface of the joint body 14 and the rotary sleeve 16, and the Y-shaped sealing ring 15 is arranged in the sealing grooves to realize high-pressure sealing of the rotary joint 5. The flange at the bottom of the rotary sleeve 16 is limited on the inner wall of the joint body 14 through the stepped surface in the joint body 14, and is fixed through the high-pressure water pressure. The rotary sleeve 16 is connected with the driving drill pipe 17 through threads.

[0023] The hydraulic directional drilling machine 6 is a caterpillar tunnel drilling machine, which provides power for drilling and reaming construction, and has a rated working torque of 6000 N.m or more and a pulling force meeting the construction requirements. The caterpillar can realize free movement and steering of the drilling machine.

[0024] The water pump 7 is used for pumping drilling fluid, maintaining the pressure of the fluid in the drilling tool and ensuring that the mechanical reaming cutter 3 can work stably. The standard pressure of the water pump is 31.5 MPa, and the flow rate is 300 L / min. When working, the water in the water tank 8 is pumped into the mechanical reaming cutter 3 to realize mechanical reaming.

[0025] The working process of the utility model is as follows:

[0026] The pilot drill bit 2 is used for breaking coal in directional drilling along the coal seam, and the mechanical reaming cutter 3 is used for rotating and cutting to break coal. The opening angle of the blade wing of the mechanical reaming cutter 3 determines the effective working radius, and the opening angle of the blade wing is determined by the built-in spring in the cutter. The extension amount of the spring is controlled by water pressure, so the flow rate of clean water and pump pressure control the effective working radius of the mechanical reaming cutter 3, and the maximum effective radius is 0.5 m. The reaming speed is controlled by the rotation speed of the hydraulic directional drilling machine 6. The hydraulic directional drilling machine 6 controls the drilling direction and controls the drilling speed of the coal seam by controlling the feeding force and rotation speed. The water pump 7 provides high-pressure water for directional drilling construction throughout the process, thereby completing drilling construction and cleaning the drilling hole. The coal dregs and water generated by drilling are directly recycled, and the coal dregs and water are separated through the vibrating screen type mud remover 9. Before each mechanical reaming construction, the water tank 8 should be added with clean water injection to avoid the accumulation of coal dregs in the hole.

Claims

1. An apparatus for drilling pre-drainage holes in coal seams, characterized in that: The system includes a pilot drill bit (2), a mechanical reamer (3), a sealing drill rod (4), a sealing rotary joint (5), a hydraulic directional drilling machine (6), a water pump (7), and a water tank (8). The pilot drill bit (2) and the mechanical reamer (3) are connected by threads. One end of the sealing drill rod (4) is connected to the mechanical reamer (3), and the other end is connected to the active drill rod (17). The active drill rod (17) is fixed on the chuck of the hydraulic directional drilling machine (6). The water inlet hose of the water pump (7) is connected to the water tank (8), and the water outlet hose of the water pump (7) is connected to the sealing rotary joint (5). The sealing rotary joint (5) and the active drill rod (17) are connected by threads.

2. The apparatus according to claim 1, characterized in that: in A vibrating screen desilter (9) is installed at the borehole opening of the coal and rock stratum (1), and the filtered water from the vibrating screen desilter (9) is returned to the water tank (8).

3. The apparatus according to claim 1 or 2, characterized in that: The sealing drill rod (4) consists of a hollow rod (10), an outer spiral blade (11), and a sealing joint (12). The outer spiral blade (11) is wrapped around the outer circumference of the hollow rod (10), and the sealing joint (12) is a tapered thread sealing joint, which is set at both ends of the hollow rod (10).

4. The apparatus according to claim 3, characterized in that: The sealing rotary joint (5) includes a joint body (14), a Y-shaped sealing ring (15), and a rotary sleeve (16). The joint body (14) has a threaded section (13) that communicates with the water outlet hose of the water pump (7). The rotary sleeve (16) is fitted inside the opposite end of the threaded section of the joint body (14). The contact surface between the joint body (14) and the rotary sleeve (16) is provided with a Y-shaped sealing ring (15). The bottom flange of the rotary sleeve (16) is limited to the inner wall of the joint body (14) through the inner stepped surface of the joint body (14). The rotary sleeve (16) is connected to the active drill rod (17) by threads.

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