A kind of anti-blowout sleeve milling and salvage drilling tool and salvage method for outburst coal seam in coal mine

Abstract

The present invention relates to a blowout prevention casing milling and salvage drilling tool and salvage method for a protruding coal seam in a coal mine. It comprises: a casing milling and salvage drill rod, the front end of which is used to install a casing milling and salvage drill bit, and the rear end is connected to a rod body, and the rod body is connected to a water toilet; a blowout prevention box, which is sleeved at the connection between the casing milling and salvage drill rod and the water toilet, and comprises a box body and a plug plate, the box body is connected to a negative pressure pipe, and the connection position of the negative pressure pipeline and the box body is located on the side of the plug plate close to the casing milling and salvage drill bit; a blowout prevention one-way valve, which is used to connect the end of the accident drilling tool in the rod body, and its inlet is connected to the water toilet, and its outlet is connected to the annulus between the casing milling and salvage drill rod and the accident drilling tool. The present invention not only realizes the sealing of the gas outflow channel during the casing milling and salvage process, but also realizes the gas extraction and pressure relief in the casing milling and salvage drilling tool, which can effectively improve the safety of the casing milling and salvage accident handling of the protruding coal seam and ensure the personal safety of the operators.

Description

Technical Field

[0001] The invention relates to a salvage drill tool and a salvage method, belonging to the technical field of coal mining, and in particular to a blowout-proof sleeve milling salvage drill tool and a salvage method for a protruding coal seam in an underground coal mine. Background Art

[0002] In recent years, with the continuous development of directional drilling technology and equipment in coal mines, directional drilling technology has been increasingly used in gas control drilling construction in coal mines, and the depth of directional drilling construction has become larger and larger. However, this is accompanied by continuous accidents in directional drilling holes, and improper accident handling often causes serious economic losses.

[0003] Milling and salvage technology is an effective technology for handling accidents in underground directional drilling holes in coal mines. In recent years, this technology has played an important role in handling accidents in underground directional drilling holes in coal mines. It not only has a high success rate in accident handling, but also causes little damage to the accident drilling tools in the hole.

[0004] However, when this technology is used to deal with accidents in directional drilling of protruding coal seams, due to the high gas content and high pressure in the protruding coal seams, when the casing milling and salvage technology is used to deal with the accidents in the hole, a large amount of high-pressure gas often gushes out from the annular channel between the casing milling and salvage drill bits and the accident drill bits, which can cause gas exceeding the limit at the least and personal injury to the operators at the worst.

[0005] To this end, in view of the above-mentioned defects, the designers of the present invention have devoted themselves to research and design, combined with the experience and achievements of long-term engagement in related industries, to research and design a coal mine underground protruding coal seam anti-blowout sleeve milling and salvage drilling tool and construction method to overcome the above-mentioned defects. Summary of the invention

[0006] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0007] The main purpose of the present invention is to solve the above-mentioned technical problems existing in the prior art, and to provide a casing milling and salvage drill tool and a construction method for anti-blowout coal seams in coal mines. The present invention realizes the safe construction of casing milling and salvage in protruding coal seams, not only realizes the sealing of the gas outflow channel during the casing milling and salvage process, but also realizes the gas extraction and pressure relief in the casing milling and salvage drill tool, which can effectively improve the safety of accident handling of casing milling and salvage in protruding coal seams and ensure the personal safety of operators.

[0008] To solve the above problems, the solution of the present invention is:

[0009] A blowout prevention sleeve milling and salvaging drilling tool for a protruding coal seam in an underground coal mine, comprising:

[0010] The casing milling and salvage drill rod has a front end for installing a casing milling and salvage drill bit and a rear end connected to a rod body, and the rod body is connected to the water stool;

[0011] The blowout prevention box is sleeved at the connection between the milling and salvage drill pipe and the water stool, and includes a box body and a plug plate. The box body is connected to the negative pressure pipe, and the connection position between the negative pressure pipeline and the box body is located on the side of the plug plate close to the milling and salvage drill bit;

[0012] The blowout prevention one-way valve is used to connect the end of the accident drilling tool, the inlet of which is connected to the water valve, and the outlet of which is connected to the annulus between the casing milling and salvage drill pipe and the accident drilling tool.

[0013] Preferably, in the above-mentioned anti-blowout sleeve milling and salvage drilling tool for a protruding coal seam in an underground coal mine, the anti-blowout one-way valve comprises a valve body, a water hole is arranged on the valve body, a piston is arranged in the valve body, and a spring is connected to one end of the piston; the piston can compress the spring under fluid pressure to move axially and open the water hole.

[0014] Preferably, in the above-mentioned anti-blowout sleeve milling and salvage drilling tool for a protruding coal seam in an underground coal mine, a sealing ring is provided between the valve body and the rod body.

[0015] Preferably, in the above-mentioned anti-blowout casing milling and salvaging drilling tool for a protruding coal seam in an underground coal mine, the anti-blowout box is connected to the gas-water separator through a negative pressure pipe.

[0016] A method for fishing a blowout prevention sleeve milling machine in a coal mine protruding coal seam, comprising:

[0017] Connect a blowout prevention check valve to the end of the accident drilling tool;

[0018] A rod body is sleeved outside the accident drilling tool and the blowout prevention check valve, a sleeve milling salvage drill bit is installed at the front end of the rod body, and the tail of the rod body is connected to a water toilet;

[0019] The water is then sent into the annular gap channel between the accident drill tool and the rod body through the blowout prevention one-way valve. The high-pressure water carries the drill cuttings and cools the casing milling and salvaging drill bit, and then returns through the annular gap channel between the rod body and the hole wall.

[0020] Preferably, the above-mentioned method for fishing outburst coal seam blowout prevention sleeve milling in coal mine underground also includes:

[0021] A blowout prevention box is arranged at the joint of the rod body and the water stool, the blowout prevention box comprises a box body and a plug plate, the box body is connected to a negative pressure pipe, and the connection position of the negative pressure pipeline and the box body is located on the side of the plug plate close to the sleeve milling and salvage drill bit;

[0022] Before removing the water toilet, insert the blowout box plug into the socket and turn on the negative pressure on the blowout box. After removing the water toilet, seal the end of the rod body with the plug and suck the gas into the extraction system through the negative pressure pipe.

[0023] Preferably, in the above-mentioned method for milling and salvaging a protruding coal seam in an underground coal mine, the blowout prevention one-way valve comprises a valve body, a water hole is arranged on the valve body, a piston is arranged in the valve body, and a spring is connected to one end of the piston; the piston can compress the spring under fluid pressure to move axially and open the water hole.

[0024] Therefore, compared with the prior art, the present invention has the following advantages:

[0025] (1) The gas outflow channel in the milling and salvage drilling tool is sealed: by installing a blowout check valve at the end of the accident drilling tool, the semi-sealed and full-sealed annular channel between the milling and salvage drilling tool and the accident drilling tool is achieved to prevent the gas in the hole from gushing out from the channel. During the milling and salvage drilling, the high-pressure water discharged by the mud pump enters the salvage drilling tool through the water and pushes the piston of the blowout check valve forward to open the water eye channel. The high-pressure water enters the annular channel between the milling and salvage drilling tool and the accident drilling tool through the water eye and reaches the bottom of the hole to discharge slag and cool the milling and salvage drill bit; when the drilling stops, the mud pump is depressurized, the blowout check valve piston is reset under the action of the spring, and the water eye channel is closed to prevent the gas in the hole from gushing out from the water eye channel.

[0026] (2) The gas extraction and pressure relief in the casing milling and salvage drilling tools are realized: by connecting the negative pressure extraction pipeline through the water stool, the gas accumulated in the casing milling and salvage drilling tools can be extracted and the pressure can be relieved. The gas pressure in the casing milling and salvage drilling tools can be detected by the pressure gauge. When the pressure on the pressure gauge drops to 0MPa, the water stool can be safely removed.

[0027] (3) The residual gas in the casing milling and salvage drill tool is extracted when adding drill pipes: the blowout preventer box can be used to safely add rods. When removing the water stool, first pull the salvage drill tool back and forth to place the sealing ring on the casing milling and salvage drill pipe joint body, then open the extraction and release negative pressure connected to the blowout preventer box, and finally remove the water stool. When the water stool is removed, the plug plate falls rapidly under the dual effects of its own gravity and artificial pressure, and blocks the end of the casing milling and salvage drill pipe. At this time, the residual gas in the casing milling and salvage drill tool is sucked into the extraction system through the blowout preventer box to prevent gas outflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable one skilled in the art to make and use the present disclosure.

[0029] Figure 1A schematic diagram of the connection of a drilling tool assembly in an embodiment of the present invention is illustrated;

[0030] Figure 2-3 The schematic diagram of the blowout prevention box in the embodiment of the present invention is illustrated, wherein: Figure 3 for Figure 2 Side view of

[0031] Figure 4 A schematic diagram of a blowout prevention check valve in an embodiment of the present invention is illustrated;

[0032] Embodiments of the present invention will be described with reference to the accompanying drawings.

[0033] 1-Milling and salvaging drill bit; 2-Milling and salvaging drill rod; 3-Joint body; 4-Rod body; 5-Accident drilling tool; 6-Blowout prevention check valve; 7-Sealing ring; 8-Piston; 9-Water eye; 10-Spring; 11-Valve body; 12-Blowout prevention box; 13-Fixing bolt; 14-Plug plate; 15-Box body; 16-Water stool; 17-Pressure gauge; 18-Hose; 19-Negative pressure pipe; 20-Mud pump; 21-Gas-water separator. DETAILED DESCRIPTION

[0034] Example

[0035] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0036] See also Figure 1 The anti-blowout casing milling and salvage drilling tool for the protruding coal seam in the coal mine described in this embodiment includes a casing milling and salvage drill bit 1, a casing milling and salvage drill rod 2, an anti-blowout check valve 6, a water stool 16 and a blowout preventer box 12.

[0037] The milling salvage drill rod 2 includes a joint body 3 and a rod body 4 .

[0038] The front end of the casing milling and salvaging drill pipe 2 is connected to the casing milling and salvaging drill bit 1, and the rear end is connected to the water sack 16. The water sack 16 is connected to the mud pump 20 through the high-pressure hose 18, and is connected to the gas-water separator 21 through the negative pressure pipe 19.

[0039] like Figure 2-3 As shown, the blowout prevention box 12 includes a box body 15 , fixing bolts 13 and a plug plate 14 .

[0040] like Figure 4 As shown, the anti-blowout check valve 6 includes a valve body 11, a sealing ring 7, a piston 8, a water hole 9 and a spring 10.

[0041] The blowout prevention box 12 is sleeved on the connection between the milling and salvaging drill pipe 2 and the water stool 16, and is radially fixed by fixing bolts 13. The blowout prevention check valve 6 is connected to the end of the accident drilling tool 5 by threads.

[0042] The present embodiment provides a method for constructing a blowout prevention sleeve milling and salvaging drill tool in a coal mine protruding coal seam, comprising the following steps:

[0043] Step 1, connect the blowout prevention check valve to the end of the accident drilling tool;

[0044] Step 2, connecting the casing milling and salvage drilling tool assembly, the drilling tool assembly is sequentially composed of the casing milling and salvage drill bit, the casing milling and salvage drill pipe and the water stool, the water stool is connected to the mud pump through a high-pressure hose, and the negative pressure pipe is connected to the gas-water separator;

[0045] Step 3, put the blowout preventer on the connection between the milling salvage drill pipe and the water pipe, and tighten the fixing bolts to achieve radial fixation;

[0046] Step 4, start the mud pump to send high-pressure water into the casing milling and salvage drilling tool. The high-pressure water pushes the piston of the blowout prevention check valve forward to open the water eye channel. The high-pressure water enters the annular gap channel between the accident drilling tool and the casing milling and salvage drilling tool through the water eye channel to the bottom of the hole to carry the drill cuttings and cool the casing milling and salvage drill bit, and finally returns from the annular channel between the casing milling and salvage drilling tool and the hole wall.

[0047] Step 5, when the drilling rig has finished drilling the remaining length, turn off the mud pump. At this time, the piston of the blowout prevention one-way valve is reset under the action of the spring force to close the water eye channel.

[0048] Step 6, open the negative pressure pipeline valve, and use negative pressure to drain the gas accumulated inside the casing milling and salvage drilling tools. When the pressure gauge reading drops to 0MPa, the water stool can be removed.

[0049] Step 7, when removing the water stool, pull the salvage drill to place the sealing ring at the joint body. Since the inner diameter of the joint body is smaller than the inner diameter of the rod body, the sealing ring is placed here for better sealing effect. Insert the blowout preventer plug plate into the socket and turn on the negative pressure on the blowout preventer. When the water stool is unscrewed, the plug plate falls rapidly under the dual effects of its own gravity and artificial pressure to seal the end of the milling and salvage drill rod. At this time, the remaining gas in the milling and salvage drill is sucked into the extraction system through negative pressure.

[0050] Step 8, continue to add rods to perform milling and salvaging, and repeat steps c to h until the milling and salvaging are completed. From the above description, it can be seen that the embodiment of the present invention has the following advantages:

[0051] 1. The sealing of the gas outflow channel in the casing milling and salvage drilling tool is realized: by installing a blowout check valve at the end of the accident drilling tool, the semi-sealing and full sealing of the annular channel between the casing milling and salvage drilling tool and the accident drilling tool is realized to prevent the gas in the hole from gushing out from the channel. When the casing milling and salvage drilling is carried out, the high-pressure water discharged by the mud pump enters the salvage drilling tool through the water and pushes the piston of the blowout check valve forward to realize the opening of the water eye channel. The high-pressure water enters the annular channel between the casing milling and salvage drilling tool and the accident drilling tool through the water eye and goes to the bottom of the hole to discharge slag and cool the casing milling and salvage drill bit; when the drilling is stopped, the mud pump is depressurized, the blowout check valve piston is reset under the action of the spring, and the water eye channel is closed to prevent the gas in the hole from gushing out from the water eye channel.

[0052] Secondly, the extraction and pressure relief of gas in the casing milling and salvage drilling tools are realized: by connecting the negative pressure extraction pipeline through the water stool, the gas accumulated in the casing milling and salvage drilling tools can be extracted and the pressure can be relieved, and the gas pressure in the casing milling and salvage drilling tools can be detected by the pressure gauge. When the pressure on the pressure gauge drops to 0MPa, the water stool can be safely removed.

[0053] Third, the extraction of residual gas in the casing milling and salvage drill tool when adding drill pipes is realized: safe rod addition can be achieved through the blowout preventer. When removing the water stool, first pull the salvage drill tool back and forth to place the sealing ring on the casing milling and salvage drill pipe joint body, then open the extraction and release negative pressure connected to the blowout preventer, and finally remove the water stool. When the water stool is removed, the plug plate falls rapidly under the dual effects of its own gravity and artificial pressure, and seals the end of the casing milling and salvage drill pipe. At this time, the residual gas inside the casing milling and salvage drill tool is sucked into the extraction system through the blowout preventer to avoid gas outflow.

[0054] In the present embodiment, although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or concurrently with other actions from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art.

[0055] Note that references in the specification to "one embodiment," "an embodiment," "an example embodiment," "some embodiments," etc. indicate that the described embodiments may include a particular feature, structure, or characteristic, but each embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, whether or not explicitly described, it would be within the knowledge of a person skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments.

[0056] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A blowout prevention sleeve milling and salvage drilling tool for a protruding coal seam in a coal mine, characterized in that: include: A milling and salvage drill rod (2) comprises a rod body (4), a milling and salvage drill bit (1) is installed at the front end of the rod body (4), and the tail end of the rod body (4) is connected to a water stool (16); The blowout prevention box (12) is sleeved at the connection between the milling and salvage drill rod (2) and the water stool (16), and comprises a box body (15) and a plug plate (14); the box body (15) is connected to a negative pressure pipe (19); the connection position between the negative pressure pipe and the box body (15) is located on a side of the plug plate (14) close to the milling and salvage drill bit (1); A blowout prevention check valve is used to connect the end of the accident drilling tool (5), the inlet of which is connected to the water toilet (16), and the outlet of which is connected to the annulus between the casing milling and salvaging drill pipe (2) and the accident drilling tool (5); before removing the water toilet, the blowout prevention box plug plate (14) is inserted into the plug port, and the negative pressure on the blowout prevention box is turned on; after removing the water toilet, the end of the rod body (4) is blocked by the plug plate (14), and the gas is sucked into the extraction system through the negative pressure pipe (19); the blowout prevention check valve (6) is connected to the end of the accident drilling tool; the rod body (4) is sleeved on the outside of the accident drilling tool and the blowout prevention check valve (6).

2. The anti-blowout sleeve milling and salvaging drilling tool for the protruding coal seam in underground coal mines according to claim 1 is characterized in that: The blowout prevention one-way valve comprises a valve body (11), a water hole (9) is arranged on the valve body (11), a piston (8) is arranged inside the valve body (11), and one end of the piston (8) is connected to a spring (10); the piston (8) can compress the spring (10) under fluid pressure to move axially and open the water hole (9).

3. The anti-blowout sleeve milling and salvaging drilling tool for the protruding coal seam in underground coal mines according to claim 2 is characterized in that: A sealing ring (7) is provided between the valve body (11) and the rod body (4).

4. The anti-blowout sleeve milling and salvaging drilling tool for the protruding coal seam in underground coal mines according to claim 2 is characterized in that: The blowout prevention box (12) is connected to the air-water separator (21) via a negative pressure pipe (19).

5. A method for salvaging a blowout-proof sleeve milling tool in a protruding coal seam in a coal mine, which is implemented by using a blowout-proof sleeve milling tool for salvaging a protruding coal seam in a coal mine according to any one of claims 1 to 4, characterized in that: include: Connect a blowout prevention check valve (6) to the end of the accident drilling tool; A rod body (4) is sleeved outside the accident drilling tool and the blowout prevention check valve (6), a sleeve milling salvage drill bit (1) is installed at the front end of the rod body (4), and the tail of the rod body (4) is connected to a water faucet (16); High-pressure water is fed into the annular gap channel between the accident drilling tool and the rod body (4) through the water valve (16) and the blowout prevention check valve (6). The high-pressure water carries the drill cuttings and cools the casing milling and salvaging drill bit (1), and then returns through the annular gap channel between the rod body (4) and the hole wall.

6. A method for anti-blowout sleeve milling and salvaging of a protruding coal seam in a coal mine according to claim 5, characterized in that: Also includes: A blowout prevention box (12) is provided at the joint between the rod body (4) and the water stool (16), the blowout prevention box (12) comprising a box body (15) and a plug plate (14), the box body (15) being connected to a negative pressure pipe (19), and the connection position between the negative pressure pipe and the box body (15) is located on a side of the plug plate (14) close to the sleeve milling and salvage drill bit (1); Before removing the toilet, the blowout prevention box plug plate (14) is inserted into the socket and the negative pressure on the blowout prevention box is turned on. After removing the toilet, the end of the rod body (4) is blocked by the plug plate (14) and the gas is sucked into the extraction system through the negative pressure pipe (19).

7. A method for fishing outburst coal seam blowout prevention sleeve milling in coal mine according to claim 5, characterized in that: The blowout prevention one-way valve comprises a valve body (11), a water hole (9) is arranged on the valve body (11), a piston (8) is arranged inside the valve body (11), and one end of the piston (8) is connected to a spring (10); the piston (8) can compress the spring (10) under fluid pressure to move axially and open the water hole (9).

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