A blowout preventer for downhole drilling

Abstract

The utility model relates to the technical field of coal mine drilling, especially to a downward drilling blowout preventer, including sleeve pipe, box, deslagging pipe and air pipe, the sleeve pipe rear end with the sleeve pipe hole of box front end middle part link to each other, the box bottom is connected with the deslagging pipe, the top of box is equipped with the air pipe, the front side inner wall of box top is equipped with first baffle, the back side inner wall of box top is equipped with second baffle, the first baffle's inner end is located the top of sleeve pipe hole, second baffle is located the top of first baffle, the utility model discloses a first baffle is arranged on the top of sleeve pipe hole, and the second baffle is arranged on the back end of the inner wall of box, so that the air pipe and the sleeve pipe hole are enclosed into the air channel of the "Z" shape through the first baffle and the second baffle, so that the air pipe can simultaneously harmful gas such as gas, avoid too much drilling slag to inhale into the air pipe, lead to the problem such as air pipe blockage.

Description

Technical Field

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

[0002] Downward drilling through layers is a gas control method used in coal roadway excavation and coal seam uncovering for protection. During downward drilling, because the drill pipe forms an angle with the ground, drill cuttings coming up from the drill pipe channel will enter the casing at an angle along the drill pipe channel. At the same time, due to the negative pressure extraction of methane and other harmful gases through the exhaust pipe at the top of the casing, some drill cuttings will be sucked into the exhaust pipe. If too much is sucked in, it may cause problems such as blockage of the exhaust pipe, preventing methane and other harmful gases from being discharged from the casing and causing unnecessary danger. In addition, there are gaps between the outer wall of the casing inserted into the drill pipe channel and the drill pipe channel, and there are also gaps between the drill pipe and the casing. Methane can leak out through these gaps, posing unnecessary danger to workers.

[0003] Based on the above reasons, this utility model designs a blowout prevention device for downward drilling. Utility Model Content

[0004] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a blowout prevention device for downward drilling. By setting a first baffle above the casing hole and a second baffle at the rear end of the inner wall of the housing, a "Z"-shaped air extraction channel is formed between the air extraction pipe and the casing hole through the first and second baffles. This allows the air extraction pipe to extract harmful gases such as methane while preventing excessive drilling cuttings from being sucked into the air extraction pipe, thus avoiding problems such as blockage of the air extraction pipe.

[0005] To achieve the purpose of this utility model, the technical solution adopted by this utility model is as follows: This utility model discloses a blowout prevention device for downward drilling, including a casing, a housing, a slag discharge pipe, and a suction pipe. The casing has a tubular structure, and its rear end is connected to the casing hole in the middle of the front end of the housing. The housing has a hollow square structure, and the slag discharge pipe is connected to its bottom. The suction pipe is provided at the top of the housing. A first baffle is provided above the front inner wall of the housing, and there is a gap between the rear end of the first baffle and the upper part of the rear inner wall of the housing. A second baffle is provided above the rear inner wall of the housing, and there is a gap between the front end of the second baffle and the upper part of the front inner wall of the housing. The inner end of the first baffle is located above the casing hole, and the second baffle is located above the first baffle.

[0006] The width of the first baffle and the second baffle is greater than half the width of the inner cavity of the box.

[0007] The top of the box body is provided with an air extraction hole for communicating with the air extraction pipe, and the air extraction hole is located above the middle of the second baffle; an "Z"-shaped air extraction channel is formed between the air extraction hole and the sleeve hole by the first baffle and the second baffle.

[0008] The front end of the outer wall of the sleeve is provided with a water injection sealing airbag, and the water injection sealing airbag includes a rubber airbag, a clamp and a water injection pipe. The rubber airbag is of a hollow ring structure. The two ends of the rubber airbag are fixed to the front end of the outer wall of the sleeve through the clamp, and the rear end of the outer wall of the rubber airbag is provided with a water injection pipe communicated with its inner cavity.

[0009] The bottom of the box body is provided with a discharge hole for connecting with a discharge funnel. The discharge funnel is of a conical structure with an inner diameter gradually decreasing from top to bottom, and the inner diameter of its top end is equal to the inner diameter of the discharge hole; the bottom end of the discharge funnel is connected to the top end of the slag discharge pipe.

[0010] An inlet drill rod hole is provided in the middle of the rear end of the box body, and the inlet drill rod hole is coaxial and equal in diameter with the sleeve hole; a rubber block is fixed on the rear wall of the box body. The rubber block is of a square structure, and a "rice"-shaped incision is provided in the middle thereof. The center of the incision coincides with the center of the inlet drill rod hole.

[0011] The beneficial effects of the present utility model are as follows: By arranging a first baffle above the sleeve hole and a second baffle at the rear end of the inner wall of the box body in the present utility model, an "Z"-shaped air extraction channel is formed between the air extraction pipe and the sleeve hole by the first baffle and the second baffle, so that while the air extraction pipe can extract harmful gases such as gas, it can avoid excessive drill slag being sucked into the air extraction pipe, resulting in problems such as blockage of the air extraction pipe.

[0012] After the water injection sealing airbag is injected with water in the present utility model, its outer wall can be closely fitted with the inner wall of the drill rod channel, preventing dangerous gases such as gas from gushing out through the gap between the sleeve and the inner wall of the drill rod channel; By arranging a rubber block with a "rice"-shaped incision in the middle on the rear wall of the box body in the present utility model, before the drill rod enters the box body through the inlet drill rod hole, it needs to first pass through the center of the "rice"-shaped incision of the rubber block, and the rubber around the "rice"-shaped incision will be closely pressed against the outer wall of the drill rod due to extrusion, so that most of the dangerous gases such as gas will not overflow from the inlet drill rod hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural view of the present utility model; Figure 2 is a top view of the present utility model; Figure 3 is Figure 2 a sectional view taken along A-A in

[0014] In the attached diagram, 1 is the casing, 2 is the housing, 3 is the slag discharge pipe, 4 is the air extraction pipe, 5 is the first baffle, 6 is the second baffle, 7 is the water injection sealing airbag, 8 is the discharge funnel, 9 is the rubber block, 10 is the notch, 21 is the casing hole, 22 is the discharge hole, 23 is the drill rod hole, 24 is the air extraction hole, 71 is the rubber airbag, 72 is the clamp, and 73 is the water injection pipe. Detailed Implementation

[0015] The present invention will be further described below: Please see Figure 1-3 , This utility model discloses a blowout prevention device for downward drilling, including a casing 1, a housing 2, a slag discharge pipe 3, and an extraction pipe 4. The casing 1 has a tubular structure, and its rear end is connected to the casing hole 21 in the middle of the front end of the housing 2. The housing 2 has a hollow square structure, and the slag discharge pipe 3 is connected to its bottom. The extraction pipe 4 is provided on the top of the housing 2. A first baffle 5 is provided above the front inner wall of the housing 2, and a gap is provided between the rear end of the first baffle 5 and the upper part of the rear inner wall of the housing 2. A second baffle 6 is provided above the rear inner wall of the housing 2. The front end of the second baffle 6 is provided with a gap between it and the upper part of the front inner wall of the housing 2; the inner end of the first baffle 5 is located above the sleeve hole 21, and the second baffle 6 is located above the first baffle 5. By setting the first baffle 5 above the sleeve hole 21 and setting the second baffle 6 at the rear end of the inner wall of the housing 2, the exhaust pipe 4 and the sleeve hole 21 are connected by the first baffle 5 and the second baffle 6 to form a "Z"-shaped exhaust channel. This allows the exhaust pipe 4 to exhaust harmful gases such as methane while avoiding excessive drilling cuttings from being sucked into the exhaust pipe 4, which could lead to blockage of the exhaust pipe 4.

[0016] Furthermore, the width of the first baffle 5 and the second baffle 6 is slightly greater than half the width of the inner cavity of the housing 2, so that the rear end of the first baffle 5 and the front end of the second baffle 6 partially overlap in the vertical direction, preventing drill cuttings from being directly sucked into the suction pipe 4 through the gap between them. The top of the housing 2 is provided with a suction hole 24 for communicating with the suction pipe 4. The suction hole 24 is located above the middle part of the second baffle 6. The suction hole 24 and the casing hole 21 are connected by the first baffle 5 and the second baffle 6 to form a "Z"-shaped suction channel.

[0017] Furthermore, a water-filled sealing airbag 7 is provided at the front end of the outer wall of the casing 1. The water-filled sealing airbag 7 includes a rubber airbag 71, clamps 72, and a water-filling pipe 73. The rubber airbag 71 has a hollow annular structure. Both ends of the rubber airbag 71 are fixed to the front end of the outer wall of the casing 1 by the clamps 72. The rear end of the outer wall of the rubber airbag 71 is provided with a water-filling pipe 73 communicating with its inner cavity. After water is injected into the water-filled sealing airbag 7, its outer wall can fit tightly against the inner wall of the drill pipe channel, preventing dangerous gases such as methane from escaping through the gap between the casing 1 and the inner wall of the drill pipe channel. The specific installation method is as follows: First, fix the two ends of the unfilled rubber airbag 71 to the front end of the outer wall of the casing 1 by the two clamps 72. Then, connect the water-filling pipe 73 at the rear end of the outer wall of the rubber airbag 71 to a water source and inject water until the outer wall of the rubber airbag 71 expands and fits tightly against the inner wall of the drill pipe channel. The water injection pipe 73 must be installed at the rear end of the outer wall of the rubber airbag 71 to prevent the middle of the outer wall of the rubber airbag 71 from expanding and tightly fitting with the drill pipe channel, which would damage the water injection pipe 73. The clamp 72 is existing technology, and its structure and working principle will not be described in detail.

[0018] Furthermore, the bottom of the housing 2 is provided with a discharge hole 22 for connection with the discharge funnel 8. The discharge funnel 8 has a conical structure with an inner diameter that gradually decreases from top to bottom, and the inner diameter of its top end is equal to the inner diameter of the discharge hole 22. The bottom end of the discharge funnel 8 is connected to the top end of the slag discharge pipe 3. By setting the discharge funnel 8, the discharge speed of the drilling slag in the housing 2 can be improved, and the accumulation of drilling slag in the housing 2 can be avoided.

[0019] Furthermore, a drill rod inlet hole 23 is provided in the middle of the rear end of the housing 2. The drill rod inlet hole 23 is coaxial and has the same diameter as the casing hole 21. A rubber block 9 is fixed on the rear wall of the housing 2. The rubber block 9 has a square structure and a "rice" shaped cut 10 in the middle. The center of the cut 10 coincides with the center of the drill rod inlet hole 23. Before the drill rod enters the housing 2 through the drill rod inlet hole 23, it first passes through the center of the "rice" shaped cut 10 of the rubber block. The rubber around the "rice" shaped cut 10 will be squeezed tightly against the outer wall of the drill rod, so that most of the dangerous gases such as methane will not overflow from the drill rod inlet hole 23.

[0020] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent modifications made based on the content of this utility model specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A blowout preventer for downward drilling, characterized in that: It includes a casing (1), a box body (2), a slag discharge pipe (3), and an air extraction pipe (4). The sleeve (1) has a tubular structure, and its rear end is connected to the sleeve hole (21) in the middle of the front end of the box (2). The box (2) has a hollow square structure, and the bottom of it is connected to the slag discharge pipe (3). The top of the box (2) is provided with the air extraction pipe (4). A first baffle (5) is provided above the front inner wall of the box (2), and there is a gap between the rear end of the first baffle (5) and the upper part of the rear inner wall of the box (2); a second baffle (6) is provided above the rear inner wall of the box (2), and there is a gap between the front end of the second baffle (6) and the upper part of the front inner wall of the box (2); the inner end of the first baffle (5) is located above the sleeve hole (21), and the second baffle (6) is located above the first baffle (5).

2. The down-blowout prevention device according to claim 1, characterized in that: The width of the first baffle (5) and the second baffle (6) is greater than half the width of the inner cavity cross section of the box body (2).

3. The down-drilling blowout preventer according to claim 2, characterized in that: The top of the box (2) is provided with an air extraction hole (24) for communicating with the air extraction pipe (4). The air extraction hole (24) is located above the middle part of the second baffle (6). The air extraction hole (24) and the sleeve hole (21) are connected by the first baffle (5) and the second baffle (6) to form a "Z"-shaped air extraction channel.

4. A blowout preventer for downward drilling according to claim 2, characterized in that: The outer wall of the sleeve (1) is provided with a water-filled sealing airbag (7) at the front end. The water-filled sealing airbag (7) includes a rubber airbag (71), a clamp (72) and a water-filled pipe (73). The rubber airbag (71) has a hollow annular structure. The two ends of the rubber airbag (71) are fixed to the front end of the outer wall of the sleeve (1) by the clamp (72). The rear end of the outer wall of the rubber airbag (71) is provided with a water-filled pipe (73) communicating with its inner cavity.

5. A blowout prevention device for downward drilling according to claim 3, characterized in that: The bottom of the box (2) is provided with a discharge hole (22) for connecting with the discharge funnel (8). The discharge funnel (8) has a tapered structure with an inner diameter that gradually decreases from top to bottom. The inner diameter of its top end is equal to the inner diameter of the discharge hole (22). The bottom end of the discharge funnel (8) is connected to the top end of the slag discharge pipe (3).

6. A blowout preventer for downward drilling according to claim 1, characterized in that: The rear end of the housing (2) is provided with a drill rod hole (23), which is coaxial and has the same diameter as the casing hole (21); a rubber block (9) is fixed on the rear wall of the housing (2), which is square in shape and has a "rice" shaped cut (10) in the middle, the center of which coincides with the center of the drill rod hole (23).

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