A system for avoiding gas escape from the interior cavity of a drill pipe during pipe replacement

Abstract

The utility model discloses a system that avoids gas from escaping from the inner cavity of the drill rod during the replacement of the drill rod, comprising: a drill rod water supply and drain pipe, a gas extraction pipe, one end of which is communicated with the drill rod water supply and drain pipe, and the other end of which is communicated with a gas extraction box; a gas observation three-way valve installed on the drill rod water supply and drain pipe; a pressure relief gas three-way valve installed on the gas extraction pipe; the utility model improvement scheme is simple, easy to operate, and low in reconstruction cost, can effectively prevent gas from overflowing from the tail of the drill rod when the drill rod is disassembled, causes the gas at the drilling site to exceed the limit, and provides effective protection for the safe construction of the underground drill hole.

Description

Technical Field

[0001] This utility model belongs to the field of coal mine production, and in particular relates to a system for preventing gas from escaping from the inner cavity of the drill pipe during drill pipe replacement. Background Technology

[0002] Hollow drill pipes are key materials for coal mine gas extraction, geological drilling, and other engineering projects. Their core feature is their hollow body, making them suitable for complex working conditions such as soft coal seams. They are mostly made of high-strength alloy steel, which combines compressive strength, torsional strength, and wear resistance, enabling them to withstand axial pressure and torque during drilling and preventing deformation or breakage.

[0003] Structurally, the drill pipe is connected by threads to form a drill string. The hollow channel can be used to transport flushing fluid and discharge rock powder, while also providing a channel for gas extraction and coal seam sampling, enabling drilling and operations to proceed simultaneously. Its small outer diameter and light weight facilitate underground transport and installation, and its excellent sealing performance prevents air and water leaks from affecting operational efficiency. As a core component connecting the drilling rig and drill bit, the hollow drill pipe directly affects drilling depth, accuracy, and operational safety, making it an essential piece of equipment for projects such as gas control in soft coal seams.

[0004] When replacing hollow drill pipes, gas is prone to escaping from the inner cavity. The main reasons are as follows:

[0005] 1. When the gas pressure inside the borehole is higher than that outside, the drill string seal is interrupted when the drill pipe is replaced, and high-pressure gas is rapidly ejected along the hollow channel.

[0006] 2. Soft coal seams have high gas content and fast desorption rate. After the drill rod disturbs the coal body, a large amount of gas is desorbed and accumulates in the inner cavity. When the drill rod is replaced, it loses its restraint and bursts out.

[0007] 3. Traditional drill pipes lack a one-way sealing structure. If the seal at the joint fails, the gas inside the cavity will leak directly into the working space. Utility Model Content

[0008] The purpose of this invention is to provide a system that prevents gas from escaping from the inner cavity of the drill pipe during drill pipe replacement, in order to solve the problem that gas easily flows out from the inner cavity when replacing hollow drill pipes.

[0009] This utility model adopts the following technical solution: a system for preventing gas from escaping from the inner cavity of the drill pipe during drill pipe replacement, comprising:

[0010] The drill rod water supply and drainage pipe has one end connected to the water supply source and the other end connected to the hollow drill rod. It is used to supply water to the hollow drill rod so that the hollow drill rod can work.

[0011] The gas extraction pipe has one end connected to the drill pipe supply and drainage pipe and the other end connected to the gas extraction box.

[0012] The gas monitoring three-way valve is installed on the drill pipe's water supply and drainage pipes.

[0013] A pressure relief gas three-way valve is installed on the gas extraction pipe;

[0014] Among them, the drill pipe water supply and drainage pipe is also used to allow gas and water in the coal seam to flow through the drill pipe water supply and drainage pipe and then through the gas observation three-way valve and the pressure relief gas three-way valve into the gas extraction box when the hollow drill pipe is not supplied with water.

[0015] The gas monitoring three-way valve is used to open the drill pipe when it is necessary to detect the gas content in the drill pipe supply and drainage pipe. The gas sensor is placed at the gas monitoring three-way valve to monitor the gas content in the gas discharged from the drill pipe supply and drainage pipe. After the gas content reaches the standard, the drill pipe supply and drainage pipe is separated from the hollow drill pipe and the hollow drill pipe is replaced.

[0016] The beneficial effects of this utility model are:

[0017] This utility model improvement scheme is simple, easy to operate, and has low modification costs. It can effectively prevent gas from overflowing from the drill rod tail when adding drill rods and disassembling the drill tail, thus preventing gas from exceeding the limit at the drilling site and providing effective protection for safe drilling operations in wells.

[0018] This invention can prevent gas from gushing out of the inner cavity when replacing hollow drill rods, and directly use the drill rod's water supply and drainage pipes to pump out gas. It also uses a gas monitoring three-way valve to monitor the gas content in the drill rod's water supply and drainage pipes, thereby preventing the problem of excessive gas levels at the working face. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Among them: 10. Drill rod water supply and drainage pipe; 11. Hollow drill rod; 12. Gas drainage pipe; 13. Observation gas three-way valve; 14. Pressure relief gas three-way valve; 15. Tail end; 16. Gas drainage box. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "multiple" means two or more.

[0023] This utility model discloses a system for preventing gas from escaping from the inner cavity of the drill pipe during drill pipe replacement, such as... Figure 1 As shown, it includes: drill pipe water supply and drainage pipe 10, gas extraction pipe 12, gas observation three-way valve 13, and pressure relief gas three-way valve 14.

[0024] One end of the drill rod water supply and drainage pipe 10 is connected to a water source, and the other end of the drill rod water supply and drainage pipe 10 is connected to the hollow drill rod 11. The drill rod water supply and drainage pipe 10 is used to supply water to the hollow drill rod 11, thereby enabling the hollow drill rod 11 to work.

[0025] One end of the gas drainage pipe 12 is connected to the drill pipe water supply and drainage pipe 10, and the other end of the gas drainage pipe 12 is connected to the gas drainage box 16.

[0026] The gas monitoring three-way valve 13 is installed on the drill pipe water supply and drainage pipe 10.

[0027] The pressure relief gas three-way valve 14 is installed on the gas extraction pipe 12.

[0028] Among them, the drill pipe water supply and drainage pipe 10 is also used to allow gas and water in the coal seam to flow through the drill pipe water supply and drainage pipe 10 and then through the gas observation three-way valve 13 and the pressure relief gas three-way valve 14 into the gas extraction box 16 when water is not supplied to the hollow drill pipe 11.

[0029] The gas monitoring three-way valve 13 is used to open the gas monitoring three-way valve 13 when it is necessary to detect the gas content in the drill pipe supply and drainage pipe 10, and to place the gas sensor at the gas monitoring three-way valve 13 to monitor the gas content in the gas discharged from the drill pipe supply and drainage pipe 10. After the gas content reaches the standard, the drill pipe supply and drainage pipe 10 is separated from the hollow drill pipe 11 and the hollow drill pipe 11 is replaced.

[0030] Preferably, the gas monitoring three-way valve 13 is installed near the hollow drill pipe 11.

[0031] Preferably, the drill pipe water supply and drainage pipe 10 is connected to the hollow drill pipe 11 via a water tail 15. Example

[0032] During the construction of the cross-layer drilling in the upper roof of the 22306 central bottom roadway, when the drilling reached the coal seam, due to the gas pressure in the original area of ​​the coal seam, gas easily overflowed from the tail of the drill rod when the drill rod was disassembled during the addition of the drill rod, causing the gas level at the drilling site to exceed the limit.

[0033] This invention addresses the problem of abnormal gas levels at the drilling site caused by gas overflowing from the drill rod tail during drill rod replacement.

[0034] Improvement approach: Use the drill pipe water supply and drainage pipe 10 as a channel for gas discharge, and add a gas observation three-way valve 13 at the water tail of the hollow drill pipe 11, and install a pressure relief gas three-way valve 14 on the gas extraction pipe 12. Before dismantling the water tail after each meter of coal hole is completed, first open the pressure relief gas three-way valve 14 to extract and depressurize the gas in the hollow drill pipe 11. The extraction and depressurization time shall not be less than 3 minutes. Then open the gas observation three-way valve 13 to observe and measure the gas situation in the hollow drill pipe 11. If the gas pressure relief in the hollow drill pipe 11 is insufficient, continue to open the pressure relief gas three-way valve 14 to extract and depressurize.

[0035] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A system for preventing gas from escaping from the inner cavity of a drill pipe during drill pipe replacement, characterized in that, include: The drill rod water supply and drainage pipe (10) has one end connected to the water supply source and the other end connected to the hollow drill rod (11) for supplying water to the hollow drill rod (11) so that the hollow drill rod (11) can work. The gas extraction pipe (12) is connected at one end to the drill pipe supply and drainage pipe (10) and at the other end to the gas extraction box (16); A gas three-way valve (13) is installed on the drill pipe supply and drainage pipe (10); A pressure relief gas three-way valve (14) is installed on the gas extraction pipe (12); The drill pipe supply and drainage pipe (10) is also used to allow gas and water in the coal seam to flow through the drill pipe supply and drainage pipe (10) and then through the gas observation three-way valve (13) and the pressure relief gas three-way valve (14) into the gas extraction box (16) when the hollow drill pipe (11) is not supplied with water. The gas monitoring three-way valve (13) is used to open the gas monitoring three-way valve (13) when it is necessary to detect the gas content in the drill pipe supply and drainage pipe (10), and place the gas sensor at the gas monitoring three-way valve (13) to monitor the gas content in the gas discharged from the drill pipe supply and drainage pipe (10). After the gas content reaches the standard, the drill pipe supply and drainage pipe (10) is separated from the hollow drill pipe (11), and the hollow drill pipe (11) is replaced.

2. The system for preventing gas from escaping from the drill pipe cavity during drill pipe replacement according to claim 1, characterized in that, The gas monitoring three-way valve (13) is installed near the hollow drill rod (11).

3. The system for preventing gas from escaping from the drill pipe cavity during drill pipe replacement according to claim 1, characterized in that, The drill pipe water supply and drainage pipe (10) is connected to the hollow drill pipe (11) via a water tail (15).

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