Downward drilling drainage device and method

Abstract

The invention discloses a downward drilling drainage device and method, and belongs to the technical field of coal mine safety. Comprising a water tank and drainage pipes, the water accumulation cylinder is arranged in the drill hole; the other end of the drainage pipe extends out of an orifice of the drill hole; upward one-way valves are arranged at the bottoms of the drainage pipes; a screen body is arranged in the water accumulation cylinder, a sliding block is slidably connected in the water accumulation cylinder, and the sliding block is connected with a power rod; the power rod is pulled through the driving device, the power rod drives the sliding block to move up and down along the water accumulation cylinder, and the sliding block is located below the screen body. A downward one-way valve is arranged on the sliding block; when the sliding block is lifted upwards, the downward one-way valve is opened, and accumulated water flows into the accumulated water cylinder; the sliding block slides downwards, the downward one-way valve is closed, the upward one-way valve is opened, and water in the water accumulation cylinder is squeezed into the water drainage pipe and drained; the device is sufficient in power and complete in drainage, has no influence on the hole sealing quality, and has no influence on the gas concentration in an extraction system; the drainage problem of the downward gas extraction drill hole is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine safety, and relates to a drilling drainage technology, in particular to a downward drilling drainage device and method. Background Art

[0002] The hydrogeological conditions of mines in my country are complex, and most coal seams have water-bearing rock layers on their roofs and floors, which increases the difficulty of gas control. In the process of gas control, through-layer drilling is usually constructed on the roof and floor of the coal seams to extract gas and control gas. However, through-layer drilling will connect the coal seams with the water-bearing rock layers, causing formation water to invade the coal body. The formation water that invades the coal body will completely or partially fill the pores or cracks of the coal body, and form water accumulation in the borehole, which brings serious difficulties to mine gas extraction.

[0003] At present, the main solutions to the formation water intrusion in the extraction borehole can be divided into two types: improving the sealing quality and removing the water in the borehole. Improving the sealing quality is difficult to effectively prevent the formation water intrusion under complex geological conditions. The main methods to remove the water in the borehole are as follows.

[0004] Chen Jiajun and Zhao Xiankai proposed to use underground compressed air to overcome the deadweight of water in the borehole and remove water from the downward borehole to improve the gas extraction efficiency. They also conducted engineering tests in Wolong Lake Coal Mine. The results showed that this method can increase the gas extraction concentration by about 7.8%, which can effectively improve the gas extraction efficiency of water-logged boreholes to a certain extent. In response to the problem of water accumulation in downward boreholes, Huainan Mining Group proposed a set of complete technologies for drilling construction, hole protection, automatic drainage at the bottom of the hole, and online monitoring of gas extraction. This technology can discharge the water in the borehole through an automatic drainage device and a compressed air system, thereby improving the gas extraction efficiency. Wang Jinliang and Liu Xiao designed an automatic drainage and slag removal system for gas extraction holes. The system uses high-pressure water injection to discharge the residue at the bottom of the borehole, and then uses compressed air to discharge the accumulated water, thereby improving the extraction efficiency of downward through-layer boreholes. Zhou Xinlong et al. used grouting to plug holes and compressed air drainage to improve the gas extraction efficiency of downward through-layer boreholes, and conducted field tests at the 17181 working face of Pansan Mine. The results showed that this method can achieve the purpose of increasing permeability and eliminating sudden changes. Gao Jiancheng et al. proposed a plugging and grouting method and drainage technology of two plugging and one injection. This method also uses high-pressure gas to regularly discharge the accumulated water in the borehole to achieve the purpose of improving gas extraction efficiency. It can be seen that the main drainage method for downward through-layer boreholes with water intrusion is the compressed air drainage method, but this method also has major defects: ① For long-distance downward through-layer boreholes, the drainage effect of this method is poor, and it is difficult to completely discharge the accumulated water in the borehole; ② Long-term regular compressed air in the borehole will dilute the gas extraction concentration, which will bring great difficulties to the later gas utilization; ③ Long-term compressed air blowing will easily blow open the poor quality of the sealing hole and the general borehole, resulting in the failure of the sealing hole, causing greater damage to the extraction system, thereby seriously affecting the extraction efficiency. Therefore, the scope of application of the above methods is limited.

[0005] In summary, for boreholes that cannot effectively remove water accumulation, especially water accumulation in long-distance water-invaded boreholes, gas extraction work has brought serious difficulties. Therefore, there are three technical problems to be solved at present: 1. When draining water from a deep borehole, compressed air cannot be used because the compressed air pressure in a coal mine is 0.4~0.6MPa. In fact, this value is often not reached underground in a coal mine. Therefore, when the depth of the downward hole is more than 30m, the water may not be drained out. 2. Compressed air drainage can easily damage the sealing quality and affect the gas concentration of the extraction system; 3. Regularly pressurizing the borehole for a long time will dilute the gas extraction concentration, thus bringing great difficulties to the subsequent gas utilization. Summary of the invention

[0006] The present invention overcomes the shortcomings of the prior art and proposes a downward borehole drainage device and method to solve the drainage problem of downward gas extraction boreholes. The present invention is achieved through the following technical solutions: A downward drilling drainage device comprises a water storage cylinder and a drainage pipe; the water storage cylinder is arranged in the drilled hole; one end of the drainage pipe is inserted into the water storage cylinder, and the other end of the drainage pipe extends out from the orifice of the drilled hole; an upward one-way valve is arranged at the bottom of the drainage pipe; a screen body is arranged in the water storage cylinder, and screen holes are arranged on the screen body; a slider is slidably connected in the water storage cylinder, and the slider is connected to a power rod, and the end of the power rod away from the slider is connected to a driving device, and the power rod is pulled by the driving device, and the power rod drives the slider to move up and down along the water storage cylinder, and the slider is located below the screen body; a downward one-way valve is arranged on the slider, and the downward one-way valve is used to connect the space above the slider with the space below the slider; When the upward one-way valve is opened, the water can only flow upward; when the downward one-way valve is opened, the water can only flow downward.

[0007] Furthermore, one end of the drainage pipe is inserted into the bottom of the water storage tank.

[0008] Furthermore, the sieve body is arranged at the top of the water storage cylinder, and the sieve body completely fills the cylinder opening at the top of the water storage cylinder.

[0009] Furthermore, the bottom of the power rod passes through the screen body and is connected to the sliding block.

[0010] Furthermore, a sealing section is provided at the top of the borehole, and the top end of the power rod passes through the sealing section and extends to the outside of the borehole opening to be connected with the driving device.

[0011] Furthermore, a sleeve is provided in the sealing section, and the power rod passes through the sleeve and is slidably connected with the sealing section.

[0012] Furthermore, the sieve body is located in or below the coal seam floor.

[0013] A downward drilling drainage method, using the downward drilling drainage device, comprises the following steps: S1, in the initial state, the slider is slid to the bottom of the water storage tank, at which time the upward one-way valve at the bottom of the drain pipe and the downward one-way valve in the slider are both in the closed state; S2. The slider is lifted upward to the position of the sieve body by the power rod. During the process of lifting the slider, the water in the borehole flowing into the water storage tank through the sieve holes on the sieve body will exert force on the downward one-way valve. Under the action of the water flow, the downward one-way valve opens, and the water in the borehole flows into the water storage tank through the downward one-way valve. During this process, the upward one-way valve is closed. As the slider is gradually lifted, more and more water is in the water storage tank until the slider reaches the sieve body position and stops. S3. Drive the power rod downward again, and the slider slides downward. At this time, the downward one-way valve is closed due to the push of the water flow. The water in the water storage tank is squeezed by the slider and the downward one-way valve, pushing open the upward one-way valve at the bottom of the drain pipe. The water in the water storage tank is squeezed into the drain pipe and flows out from the drilled hole.

[0014] Furthermore, steps S1 to S3 are repeated multiple times until all the accumulated water in the borehole is drained.

[0015] The beneficial effects of the present invention compared with the prior art are as follows: 1. The sliding process of the slider of the present invention is externally powered, and can be powered by manpower, pneumatic or electric according to the depth, and can be equipped with a transmission. Its power can reach several times or even dozens of times that of compressed air, and water will not be unable to be discharged due to insufficient power.

[0016] 2. The present invention does not require compressed air drainage, has no effect on the sealing quality, and therefore does not involve air leakage and the like, and has no effect on the gas concentration of the extraction system.

[0017] 3. The present invention uses mechanical power to make the slider reciprocate, and does not use compressed air to drain water, so air will not be injected into the hole, and has no effect on the gas concentration in the extraction system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the downward drilling drainage device of the present invention; Figure 2 for Figure 1 The enlarged view of point A in the middle; In the above picture: 1-water storage tank; 2-drain pipe; 3-drill hole; 4-upward one-way valve; 5-sieve body; 6-sieve hole; 7-slider; 8-power rod; 9-downward one-way valve; 10-sealing section; 11-casing. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail in conjunction with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The technical solutions of the present invention are described in detail below in conjunction with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.

[0020] See also Figure 1 and Figure 2 This embodiment proposes a downward drilling drainage device, including a water accumulation cylinder 1 and a drainage pipe 2; the water accumulation cylinder 1 is arranged in a borehole 3; the borehole 3 is a downward borehole, that is, a borehole drilled from the top to the bottom plate of the coal seam; there is accumulated water in the borehole 3, and the purpose of using this device is to completely drain the accumulated water in the borehole 3.

[0021] One end of the drainage pipe 2 is inserted into the water storage cylinder 1 and close to the bottom of the water storage cylinder 1, and the other end of the drainage pipe 2 extends from the orifice of the borehole 3; an upward check valve 4 is arranged at the bottom of the drainage pipe 2; after the upward check valve 4 is opened, the water can only flow upward; a sieve body 5 is arranged at the top of the water storage cylinder 1, and the sieve body 5 completely fills the top cylinder mouth of the water storage cylinder 1, and the sieve body 5 is provided with sieve holes 6, and the sieve body 5 plays a filtering role, which can screen coal slag, rock slag and water, and protect the slider 7 at the bottom of the sieve body 5 and the inner wall of the water storage cylinder 1; a slider 7 is slidably connected in the water storage cylinder 1, and the slider 7 is connected to the power rod 8, and the bottom of the power rod 8 passes through the sieve body 5 and is connected to the slider 7. A sealing section 10 is arranged at the top of the borehole 3, and the top of the power rod 8 passes through the sealing section 10 and extends to the outside of the orifice of the borehole 3. A casing 11 is arranged in the sealing section 10, and the power rod 8 passes through the casing 11 and is slidably connected to the sealing section 10.

[0022] And a driving device is connected to the top of the power rod 8; the driving device can be hydraulically driven or electrically driven, and the power rod 8 is pulled by the driving device, and the power rod 8 drives the slider 7 to move up and down along the water storage cylinder 1, and the slider 7 is located below the screen body 5; a downward one-way valve 9 is provided on the slider 7, and the downward one-way valve 9 is used to connect the space above the slider 7 with the space below the slider 7 after it is opened; after the downward one-way valve 9 is opened, the water can only flow downward.

[0023] In practical applications, the screen body 5 of the water accumulation cylinder 1 can be placed in the coal seam floor or deeper, so that the water surface in the borehole 3 can be drained below the coal seam floor to ensure that the coal seam is not soaked by water, improve gas extraction efficiency, and ensure safe production in the mine.

[0024] The principle of the downward drilling drainage device is the communicating vessel principle, and the drainage pipe 2 and the water storage tank 1 form a communicating vessel; specifically, by adopting the device, a downward drilling drainage method is also proposed, including the following steps: S1, initial state: slide the slider 7 to the bottom of the water storage tank 1, at which time the upward one-way valve 4 at the bottom of the drain pipe 2 and the downward one-way valve 9 in the slider 7 are both in the closed state; S2. The slider 7 is lifted upward to the position of the sieve body 5 by the power rod 8. During the process of lifting the slider 7, the water in the borehole 3 flowing into the water storage tank 1 through the sieve holes 6 on the sieve body 5 will exert a force on the downward one-way valve 9. Under the action of the water flow, the downward one-way valve 9 opens, and the water in the borehole 3 flows into the water storage tank 1 through the downward one-way valve 9; during this process, the upward one-way valve 4 is closed to ensure that the water in the drain pipe 2 does not flow into the water storage tank 1; as the slider 7 is gradually lifted, the water in the water storage tank 1 increases, until the slider 7 reaches the position of the sieve body 5 and stops; S3. Drive the power rod 8 downward again, and the slider 7 slides downward. At this time, the downward one-way valve 9 is closed due to the push of the water flow. The water in the water storage tank 1 is squeezed by the slider 7 and the downward one-way valve 9, pushing open the upward one-way valve 4 at the bottom of the drain pipe 2. The water in the water storage tank 1 is squeezed into the drain pipe 2 and discharged, and a drainage process is completed.

[0025] Steps S1 to S3 are repeated multiple times until all the accumulated water in the borehole 3 is drained.

[0026] The sliding process of the slider in this device is externally powered, and can be powered by manpower, pneumatic or electric according to the depth, and can be equipped with a transmission. Its power can reach several times or even dozens of times that of compressed air, and water will not be discharged due to insufficient power. This method does not use compressed air to drain water, has no effect on the quality of the sealing hole, and therefore does not involve leakage and other situations, and has no effect on the gas concentration in the extraction system. This method uses mechanical power to reciprocate the slider 7, and does not use compressed air to drain water, so air will not be injected into the hole, and has no effect on the gas concentration in the extraction system.

[0027] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be determined that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the present invention, which should be regarded as belonging to the present invention and the scope of patent protection determined by the submitted claims.

Claims

1. A downward drilling drainage device, characterized in that: The invention comprises a water storage cylinder (1) and a drainage pipe (2); the water storage cylinder (1) is arranged in a borehole (3); one end of the drainage pipe (2) is inserted into the water storage cylinder (1), and the other end of the drainage pipe (2) extends out from the orifice of the borehole (3); an upward check valve (4) is arranged at the bottom of the drainage pipe (2); a screen body (5) is arranged in the water storage cylinder (1), and screen holes (6) are arranged on the screen body (5); a slider (7) is slidably connected in the water storage cylinder (1), and the slider (7) is connected to a power rod (8), and the end of the power rod (8) away from the slider (7) is connected to a driving device, and the power rod (8) is pulled by the driving device, and the power rod (8) drives the slider (7) to move up and down along the water storage cylinder (1), and the slider (7) is located below the screen body (5); a downward check valve (9) is arranged on the slider (7), and after the downward check valve (9) is opened, it is used to connect the space above the slider (7) with the space below the slider (7); When the upward one-way valve (4) is opened, the water can only flow upward; when the downward one-way valve (9) is opened, the water can only flow downward.

2. A downward drilling drainage device according to claim 1, characterized in that: One end of the drainage pipe (2) is inserted into the bottom of the water storage tank (1).

3. A downward drilling drainage device according to claim 1, characterized in that: The sieve body (5) is arranged on the top of the water storage tank (1), and the sieve body (5) completely fills the top tank opening of the water storage tank (1).

4. A downward drilling drainage device according to claim 1, characterized in that: The bottom of the power rod (8) passes through the screen body (5) and is connected to the sliding block (7).

5. A downward drilling drainage device according to claim 4, characterized in that: A sealing section (10) is provided at the top of the borehole (3), and the top end of the power rod (8) passes through the sealing section (10) and extends to the outside of the opening of the borehole (3) to be connected to a driving device.

6. A downward drilling drainage device according to claim 5, characterized in that: A sleeve (11) is provided in the hole sealing section (10), and the power rod (8) passes through the sleeve (11) and is slidably connected to the hole sealing section (10).

7. A downward drilling drainage device according to claim 1, characterized in that: The sieve body (5) is located in or below the coal seam floor.

8. A downward drilling drainage method, characterized in that: A downward drilling drainage device as described in any one of claims 1 to 7 is used; comprising the following steps: S1, in the initial state, the slider (7) is slid to the bottom of the water storage tank (1), at which time the upward one-way valve (4) at the bottom of the drainage pipe (2) and the downward one-way valve (9) in the slider (7) are both in a closed state; S2. The slider (7) is lifted upward to the position of the sieve body (5) by means of the power rod (8). In the process of lifting the slider (7), water in the borehole (3) flows into the water storage tank (1) through the sieve holes (6) on the sieve body (5), and exerts a force on the downward one-way valve (9). Under the action of the water flow, the downward one-way valve (9) opens, and the water in the borehole (3) flows into the water storage tank (1) through the downward one-way valve (9). In this process, the upward one-way valve (4) is closed. As the slider (7) is gradually lifted upward, more and more water is contained in the water storage tank (1), until the slider (7) reaches the position of the sieve body (5) and stops. S3, the power rod (8) is then driven downward, and the slider (7) slides downward. At this time, the downward one-way valve (9) is closed due to the push of the water flow, and the water in the water storage tank (1) is squeezed by the slider (7) and the downward one-way valve (9), pushing open the upward one-way valve (4) at the bottom of the drainage pipe (2), and the water in the water storage tank (1) is squeezed into the drainage pipe (2) and discharged.

9. A downward drilling drainage method according to claim 8, characterized in that: Steps S1 to S3 are repeated multiple times until all the accumulated water in the borehole (3) is drained.

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