Blowout preventer for gas extraction drilling

Abstract

The utility model relates to the technical field of coal mine underground drilling construction, in particular to a gas extraction drilling blowout preventer, and mainly solves the technical problem that gas overflow at the tail of a drill rod after water is removed cannot be effectively treated in the prior art. The device comprises a water supply assembly, a drainage assembly and a negative pressure assembly, the water supply assembly comprises a pump truck, a water supply pipe and a water supply valve, the drainage assembly comprises a drainage pipe, a drainage valve, a buffer water tank and a return pipe, and the negative pressure assembly comprises an extraction pipe, an extraction valve, a drainage device and a gas extraction device. When the water stool needs to be detached, the extraction valve and the drainage valve are opened, the water supply valve is closed, if the hole building-up phenomenon exists in a drill hole, a gas-water mixture can enter the drainage device through the extraction pipe under the pressure difference effect, gas and other gas are drained into the gas extraction device under the negative pressure effect of the gas extraction device, and therefore gas overflow can be avoided; meanwhile, the drain pipe, the buffer water tank and the return pipe form a water circulation system, and pump suffocation can be effectively avoided.

Description

Technical Field

[0001] This utility model relates to the field of underground drilling construction technology in coal mines, and in particular to a blowout prevention device for gas drainage boreholes. Background Technology

[0002] Gas control during gas drainage drilling is a key and challenging aspect of mine safety management, as numerous gas exceedance accidents have resulted from inadequate preventative measures. The main causes of gas overflow during drilling include coal face fissures, inadequate borehole sealing, and pressure release caused by the drill rod tail opening to the outside after water removal. For gas overflow from coal face fissures, shallow-hole grouting or coal wall spraying can largely solve the problem. For gas overflow from the borehole opening, installing blowout preventers with negative pressure systems and sealing gaskets at the opening can divert the gas and prevent further overflow to some extent.

[0003] However, the issue of gas overflow from the drill pipe tail after water removal is highly uncertain: if the borehole is unobstructed during drilling, the continuous extraction and drainage by the negative pressure system at the borehole opening will prevent gas accumulation, and no gas will gush out after water removal; however, if soft coal, borehole collapse, or blockage occurs during construction, it will cause poor slag return, reduced slag discharge at the borehole opening, or even borehole stagnation. After water removal, the drill pipe tail, as the only pressure relief outlet, will instantly release a large amount of gas, water, and slag mixture, and the overflowing gas will permeate the working space and cannot be handled by the extraction system, easily causing a gas accident. Therefore, whether gas will overflow from the drill pipe tail after water removal is highly uncertain, which is a difficult and crucial point in gas control during drilling operations, and currently, effective countermeasures are still lacking. Utility Model Content

[0004] To overcome the technical defects of existing technologies that cannot effectively handle the problem of gas overflow at the tail of the drill rod after disassembly and water extraction, this utility model provides a blowout prevention device for gas extraction boreholes.

[0005] The gas extraction borehole blowout prevention device provided by this utility model includes:

[0006] A water supply assembly includes a pump truck, a water supply pipe, and a water supply valve. The rear end of the water supply pipe is connected to the pump truck, and the front end is used to connect to a water outlet. The water supply valve is installed in the middle of the water supply pipe.

[0007] A drainage assembly includes a drain pipe, a drain valve, a buffer tank, and a return pipe. One end of the drain pipe is connected to a water supply pipe section located behind the water supply valve, and the other end is connected to the buffer tank. The drain valve is installed in the drain pipe. One end of the return pipe is connected to the buffer tank, and the other end is connected to the pump truck.

[0008] The negative pressure assembly includes an extraction pipe, an extraction valve, a water drainer, and a gas extractor. One end of the extraction pipe is connected to a water supply pipe section located in front of the water supply valve, and the other end is connected to the water drainer. The extraction valve is installed in the extraction pipe, and the gas extractor is connected to the top of the water drainer.

[0009] Optionally, the gas extractor includes a negative pressure main pipe and a negative pressure branch pipe. The negative pressure main pipe is used to connect to a negative pressure source to form a negative pressure environment. One end of the negative pressure branch pipe is connected to the negative pressure main pipe and the other end is connected to the top of the water dispenser.

[0010] The technical solution provided by this utility model has the following advantages compared with the prior art:

[0011] The gas extraction borehole blowout prevention device provided by this utility model has two branches on the water supply pipe. One branch is used to install a negative pressure component, and the other branch is used to install a drainage component. On the one hand, during normal drilling, the water supply valve is opened and the extraction valve and drainage valve are closed. The pump truck pumps water into the water tank through the water supply pipe, ensuring normal water supply for drilling operations. On the other hand, when it is necessary to dismantle the water tank, the extraction valve and drainage valve are opened and the water supply valve is closed. If there is a blockage in the borehole, the gas-water mixture will enter the drain pipe through the extraction pipe under the pressure difference. The liquid is discharged through the drain pipe, and the gas, such as methane, is guided into the gas extractor under the negative pressure. This achieves a blowout prevention effect and also prevents gas overflow. At the same time, the water output by the pump truck returns to the pump truck through the drainage pipe, buffer tank, and return pipe, forming a water circulation system, which can effectively prevent pump blockage. This device can be converted and adjusted according to drilling needs, which can not only ensure the normal operation of the system water supply, but also effectively solve the problem of gas overflow at the tail of the drill rod after disassembly of the water pipe. Attached Figure Description

[0012] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram showing the structure of the blowout prevention device for gas extraction boreholes in an embodiment of this utility model.

[0015] In the picture:

[0016] 1. Pump truck; 2. Water supply pipe; 3. Water supply valve; 4. Drainage pipe; 5. Drainage valve; 6. Buffer tank; 7. Return pipe; 8. Extraction pipe; 9. Extraction valve; 10. Water discharge device; 11. Negative pressure main pipe; 12. Negative pressure branch pipe. Detailed Implementation

[0017] To better understand the above-mentioned objectives, features, and advantages of this utility model, the solution of this utility model will be further described below. It should be noted that, unless otherwise specified, the embodiments of this utility model and the features thereof can be combined with each other.

[0018] Many specific details are set forth in the following description in order to provide a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the present invention, and not all embodiments.

[0019] The following is combined Figure 1 The specific embodiments of this utility model will be described in detail below.

[0020] This embodiment provides a blowout prevention device for gas extraction boreholes, including a water supply component, a drainage component, and a negative pressure component.

[0021] The water supply assembly includes a pump truck 1, a water supply pipe 2, and a water supply valve 3. The rear end of the water supply pipe 2 is connected to the pump truck 1, and the front end is used to connect to the water supply pipe. The water supply valve 3 is installed in the middle of the water supply pipe 2.

[0022] It is easy to understand that the water braid is a mature structure in this field, also known as a water splice. It consists of a rotary joint, a pipe interface, and a sealing device. One end is connected to the high-pressure water supply pipe 2, and the other end is connected to the tail end of the drill rod. It is mainly used to maintain the continuous supply of high-pressure water when the drill rod rotates, while preventing the pipe from being damaged by torque entanglement. The water braid is connected between the water supply pipe 2 and the drill rod. When drilling reaches the target position, the water braid needs to be removed to lengthen the drill rod. After the water braid is removed, the tail end of the drill rod, as the only pressure relief port, will instantly discharge a large amount of gas, water, and slag mixture.

[0023] The drainage assembly includes a drain pipe 4, a drain valve 5, a buffer tank 6, and a return pipe 7. One end of the drain pipe 4 is connected to the water supply pipe 2 section located behind the water supply valve 3, and the other end is connected to the buffer tank 6. The drain valve 5 is installed in the drain pipe 4. One end of the return pipe 7 is connected to the buffer tank 6, and the other end is connected to the pump truck 1.

[0024] It should be noted that the main function of the drainage component is to create water circulation during the disassembly of the sewage system, so as to keep the pump truck 1 working continuously and avoid pump blockage.

[0025] The negative pressure assembly includes an extraction pipe 8, an extraction valve 9, a water drainer 10, and a gas extractor. One end of the extraction pipe 8 is connected to the water supply pipe 2 section located in front of the water supply valve 3, and the other end is connected to the water drainer 10. The extraction valve 9 is installed in the extraction pipe 8, and the gas extractor is connected to the top of the water drainer 10.

[0026] It is easy to understand that the water drainer 10 is a mature structure in this field and is mainly used to automatically drain the water in the pipeline; the gas extractor is also a mature structure in this field and is mainly used to divert gas to the target location through negative pressure to prevent gas from overflowing.

[0027] It should be noted that before dismantling the water pipe, the extraction valve 9 and the drainage valve 5 are opened and the water supply valve 3 is closed. The gas extractor creates a negative pressure outside the water pipe. If there is a blockage in the borehole, it will inevitably gush out under the pressure difference and discharge the gushing gas-water mixture into the drain 10. This eliminates the uncertainty of gas overflow at the tail of the drill rod after dismantling the water pipe and ensures operational safety.

[0028] Specifically, the gas extractor includes a negative pressure main pipe 11 and a negative pressure branch pipe 12. The negative pressure main pipe 11 is used to connect to a negative pressure source to form a negative pressure environment. One end of the negative pressure branch pipe 12 is connected to the negative pressure main pipe 11, and the other end is connected to the top of the water drainer 10. In use, the gas in the gas-water mixture is dispersed at the top of the water drainer 10 and guided into the gas extractor under the action of negative pressure.

[0029] The working principle of the blowout prevention device for gas extraction boreholes in this embodiment is as follows:

[0030] During normal drilling, the extraction valve 9 and drainage valve 5 are closed and the water supply valve 3 is opened. The pump truck 1 pumps water into the water tank through the water supply pipe 2 to provide sufficient water for drilling operations.

[0031] When drilling reaches the target depth and it is necessary to disassemble the water supply and extend the drill rod, open the extraction valve 9 and the drain valve 5 and close the water supply valve 3. If there is a blockage in the borehole, the gas-water mixture will enter the drain pipe 8 and the water discharger 10 under the action of pressure difference. The liquid will be discharged through the water discharger 10, and the gas such as methane will be guided into the methane extractor under the negative pressure of the methane extractor. At the same time, the water output from the pump truck 1 will return to the pump truck 1 through the drain pipe 4, the buffer tank 6 and the return pipe 7 in sequence, forming a water circulation system.

[0032] Once the gushing stops and the situation returns to normal, disassemble the water pipe, install the extended drill rod, reconnect the water pipe, and then resume the normal drilling operation.

[0033] It should be noted that in actual design, the water supply valve 3, extraction valve 9 and drainage valve 5 can be integrated on the drilling rig control panel so that the drilling rig operator can make adjustments at any time.

[0034] The above description is merely a specific embodiment of this utility model, enabling those skilled in the art to understand or implement it. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and all should be covered by the protection scope of the claims.

Claims

1. A blowout prevention device for gas drainage boreholes, characterized in that, include: The water supply assembly includes a pump truck (1), a water supply pipe (2) and a water supply valve (3). The rear end of the water supply pipe (2) is connected to the pump truck (1) and the front end is used to connect to the water supply pipe. The water supply valve (3) is installed in the middle of the water supply pipe (2). The drainage assembly includes a drain pipe (4), a drain valve (5), a buffer tank (6), and a return pipe (7). One end of the drain pipe (4) is connected to the water supply pipe (2) section located behind the water supply valve (3), and the other end is connected to the buffer tank (6). The drain valve (5) is installed in the drain pipe (4). One end of the return pipe (7) is connected to the buffer tank (6), and the other end is connected to the pump truck (1). The negative pressure assembly includes an extraction pipe (8), an extraction valve (9), a water drainer (10), and a gas extractor. One end of the extraction pipe (8) is connected to a water supply pipe (2) section located in front of the water supply valve (3), and the other end is connected to the water drainer (10). The extraction valve (9) is installed in the extraction pipe (8), and the gas extractor is connected to the top of the water drainer (10).

2. The blowout prevention device for gas drainage boreholes according to claim 1, characterized in that, The gas extractor includes a negative pressure main pipe (11) and a negative pressure branch pipe (12). The negative pressure main pipe (11) is used to connect to a negative pressure source to form a negative pressure environment. One end of the negative pressure branch pipe (12) is connected to the negative pressure main pipe (11) and the other end is connected to the top of the water dispenser (10).

Images