Underground water seal type gas blowout prevention system

Abstract

The utility model discloses an underground water seal type gas blowout prevention system which comprises an inner inserting sleeve arranged at a drilling opening, and the outer end of the inner inserting sleeve is connected with a section of blowout prevention sleeve. The top of the first section of blowout prevention sleeve is connected to a header pipe located at the top of a roadway through a first drainage sub-pipe; the bottom of the first-section blowout prevention sleeve is connected with a slag receiving box, and the lower part of the slag receiving box is communicated to a water seal container; a water seal vertical plate is arranged in the water seal container, and the bottom end of the water seal vertical plate is located below the liquid level in the water seal container. The inner cavity of the water seal container is divided into a gas discharge cavity and a slag discharge cavity by the water seal vertical plate; the gas discharge cavity is connected to a main pipe through a first drainage opening of the gas discharge cavity, and the gas discharge cavity is further connected with a gas collection bag; according to the utility model, the water seal system is additionally arranged below the section of blowout prevention sleeve, so that when the gas pressure is large, a large part of gas can be buffered by the slag receiving box and the water seal container and then enters the main pipe of the drainage system, and the gas discharge pressure of the first drainage sub-pipe in the original drainage system is greatly reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal mine gas blowout prevention, in particular to an underground water-sealed gas blowout prevention system. Background Art

[0002] In the coal mining process, underground mining is crucial to coal mining efficiency. In order to speed up the mining progress and shorten the mining cycle, coal mines usually need to conduct underground drilling.

[0003] Gas generated during underground coal mining mixes with air and forms flammable gases, posing a significant safety hazard. Through pre-drilling, deep gas pipelines can be brought to the surface, enabling gas extraction and treatment, ensuring mining safety.

[0004] Advance drilling is an effective method to prevent gas outbursts. Underground advance drilling is done by drilling several holes in front of the working face to artificially create and maintain a longer pressure relief zone, avoiding stress concentration and high-pressure gas near the working face, thereby eliminating the risk of outbursts.

[0005] During advance drilling, an inner casing is typically installed at the borehole opening. A blowout preventer (BOP) is then connected to the inner casing. This BOP is then connected to the main pipe of the extraction system, through which gas is extracted from the wellbore. However, excessive gas pressure can damage the BOP, leading to excessive gas levels in the tunnel and compromising construction safety. Utility Model Content

[0006] The utility model aims to provide an underground water-sealed gas blowout prevention system to avoid gas leakage at the blowout prevention casing when the gas pressure is too high.

[0007] The utility model adopts the following technical solutions: an underground water-sealed gas blowout prevention system, comprising an inner insert casing arranged at the borehole mouth, the outer end of the inner insert casing being connected to a section of blowout prevention casing;

[0008] The top of a section of blowout prevention casing is connected to the main pipe located at the top of the roadway through the first extraction sub-pipe;

[0009] The bottom of a section of the blowout prevention casing is connected to a slag receiving box, and the bottom of the slag receiving box is connected to a water seal container; wherein the area of the connection between the section of the blowout prevention casing and the first extraction sub-pipe is smaller than the area of the connection between the section of the blowout prevention casing and the slag receiving box;

[0010] A water seal plate is provided in the water seal container, the bottom end of which is located below the liquid level in the water seal container; the water seal plate divides the inner cavity of the water seal container into a gas discharge cavity and a slag discharge cavity;

[0011] The gas discharge chamber is connected to the main pipe through its first extraction port, and the gas discharge chamber is also connected to a gas collecting bag.

[0012] Furthermore, a first dust-proof nozzle is provided in the slag receiving box, and a liquid spraying port of the first dust-proof nozzle faces a connection port between a section of the blowout prevention sleeve and the slag receiving box.

[0013] Furthermore, a flushing pipe is provided in the slag receiving box, and the flushing pipe is directed toward the bottom outlet of the slag receiving box.

[0014] Furthermore, the slag receiving box is connected to the water seal container through a transmission pipeline.

[0015] Furthermore, a second section of blowout prevention casing is provided at the free end of the first section of blowout prevention casing, and a spare slag receiving box is provided at the bottom of the second section of blowout prevention casing.

[0016] Furthermore, the gas discharge chamber is a closed chamber, and a first extraction port and a second extraction port are respectively provided on the top thereof;

[0017] The first extraction port is connected to the main pipe through the second extraction sub-pipe;

[0018] The second extraction port is connected with an air collecting bag.

[0019] Furthermore, a second dust-proof nozzle is provided in the gas discharge chamber, and a liquid spraying port of the second dust-proof nozzle is directed toward the slag inlet of the water seal container;

[0020] A dust shielding plate is also provided near the slag inlet in the gas discharge chamber. The dust shielding plate extends downward from the top plate of the water seal container, and there is a gap between the lower end of the dust shielding plate and the liquid surface in the water seal container.

[0021] Furthermore, the top of the slag discharge chamber is open.

[0022] Furthermore, the water seal container is provided with an overflow port and a drain port;

[0023] The height of the overflow outlet is higher than the bottom end of the water seal vertical plate and lower than the bottom end of the dust isolation plate.

[0024] Furthermore, the air collecting bag is also connected to the main pipe through the third extraction sub-pipe.

[0025] The beneficial effect of the present invention is that: by adding a water seal system below a section of blowout prevention casing, when the gas pressure is high, a large part of the gas can enter the main pipe of the extraction system through the buffering of the slag box and the water seal container, thereby greatly reducing the gas discharge pressure of the first extraction sub-pipe in the original extraction system and reducing the risk of gas leakage into the tunnel when the gas pressure is too high. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a structural diagram of an underground water-sealed gas blowout prevention system in an embodiment of the present utility model;

[0027] Figure 2This is a schematic structural diagram of a water seal container in an embodiment of the present utility model;

[0028] Figure 3 Schematic diagram of the internal structure of the water seal container in the embodiment of the present utility model.

[0029] Among them: 10. Main pipe; 11. First extraction and discharge sub-pipe; 12. Second extraction and discharge sub-pipe; 13. Third extraction and discharge sub-pipe;

[0030] 21. First stage blowout prevention casing; 22. Second stage blowout prevention casing; 23. Slag receiving box; 24. First dust prevention nozzle; 25. Flush pipe; 26. Spare slag receiving box;

[0031] 31. Second dust-proof nozzle; 32. Dust screen; 33. Water seal plate; 34. Overflow port; 35. Drain port; 36. First extraction port; 37. Slag inlet; 38. Second extraction port;

[0032] 40. Transmission pipeline; 50. Air collection bag; 60. Internal sleeve. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0034] The utility model discloses an underground water-sealed gas blowout prevention system. Figure 1 As shown, it includes an inner sleeve 60 arranged at the mouth of the borehole, and the outer end of the inner sleeve 60 is connected to a section of blowout prevention casing 21; the top of a section of blowout prevention casing 21 is connected to the main pipe 10 at the top of the tunnel through the first pumping sub-pipe 11; the bottom of a section of blowout prevention casing 21 is connected to a slag receiving box 23, and the bottom of the slag receiving box 23 is connected to a water seal container; wherein, the area of the connection port of a section of blowout prevention casing 21 and the first pumping sub-pipe 11 is smaller than the area of the connection port of a section of blowout prevention casing 21 and the slag receiving box 23; a water seal vertical plate 33 is provided in the water seal container, and the bottom end of the water seal vertical plate 33 is located below the liquid level in the water seal container; the water seal vertical plate 33 divides the inner cavity of the water seal container into a gas discharge chamber and a slag discharge chamber, the gas discharge chamber is connected to the main pipe through its first pumping port 36, and the gas discharge chamber is also connected to an air collecting bag 50.

[0035] Among them, Figure 1 In the water-sealed container in FIG, the shaded portion at the bottom represents slag and the dotted portion represents liquid.

[0036] The utility model adds a water seal system below a section of blowout prevention casing. When the gas pressure is high, a large part of the gas can enter the main pipe of the extraction system through the buffering of the slag box and the water seal container, thereby greatly reducing the gas discharge pressure of the first extraction sub-pipe in the original extraction system and reducing the risk of gas leakage into the tunnel when the gas pressure is too high.

[0037] In the embodiment of the present invention, the inner sleeve is inserted into the drill hole and fixed to the drill hole. When drilling, the drill rod is inserted into the drill hole from the inside of the inner sleeve to perform the operation. A section of the blowout prevention casing 21 is fixedly connected to the inner sleeve 60 and realizes the sealing of the side of the drill rod to prevent gas from leaking directly into the tunnel.

[0038] The slag box 23 can not only lead out excess gas, but also discharge drill cuttings generated during drilling construction.

[0039] A first dust-proof nozzle 24 is provided in the slag box 23. The liquid spray port of the first dust-proof nozzle 24 is directed toward the connection between the blowout-proof casing 21 and the slag box 23. Since the gas discharged from the connection includes gas and slag, smoke and dust are inevitably generated. Therefore, the dust-reducing liquid sprayed into the connection through the first dust-proof nozzle 24 can play a dust-reducing role.

[0040] A flushing pipe 25 is provided in the slag receiving box 23, and the flushing pipe 25 is toward the bottom outlet of the slag receiving box 23. In addition, since slag is solid and easily clogged at the outlet of the receiving box 23, the flushing pipe 25 is provided here to flush the slag into the water seal container through a high-pressure water source.

[0041] In the present invention, the slag receiving box 23 is connected to the water seal container via a transmission pipe 40. Because a drilling rig must be installed at the borehole entrance and the tunnel is confined, the water seal container needs to be located elsewhere. Therefore, the transmission pipe 40 is added. Preferably, the transmission pipe 40 is a metal hose, which has a self-shaping effect, facilitating the transfer of slag, and can be designed with a different route direction based on on-site working conditions.

[0042] In one embodiment, a second-stage blowout prevention casing 22 is provided at the free end of the first-stage blowout prevention casing 21. A spare slag receiving box 26 is provided at the bottom of the second-stage blowout prevention casing 22. Normally, only one-stage blowout prevention casing 21 is sufficient, but to increase system safety, a second-stage blowout prevention casing 22 is added. Seal rings are also added between the two and at locations requiring sealing to ensure sealing performance.

[0043] like Figure 2 As shown, the gas discharge chamber of the water-sealed container is a closed chamber with a first extraction port 36 and a second extraction port 38 at its top. The first extraction port 36 is connected to the main pipe 10 via the second extraction sub-pipe 12; the second extraction port 38 is connected to a gas collection bag 50. When the gas pressure is too high, the gas in the chamber can be directly extracted through the first extraction port 36, relieving the extraction pressure of the first extraction sub-pipe 11. As the gas pressure continues to increase, the gas enters the gas collection bag 50 under pressure, which buffers the gas and further reduces the gas discharge pressure.

[0044] A second dust-proof nozzle 31 is provided in the gas discharge chamber, and the liquid spraying port of the second dust-proof nozzle 31 is directed toward the slag inlet 37 of the water seal container; a dust-proof plate 32 is also provided near the slag inlet 37 in the gas discharge chamber, and the dust-proof plate 32 extends downward from the top plate of the water seal container, and there is a gap between its lower end and the liquid level in the water seal container.

[0045] The second dust-proof nozzle 31 further removes dust from the slag. Furthermore, the dust shield 32 confines dust near the slag inlet 37, preventing it from entering the gas collection bag 50 or the main pipe 10. The dust shield 32 can be shaped like an arc or wave, wrapping around the slag inlet 37. It is important to ensure a gap between the bottom end of the dust shield 32 and the liquid level in the water seal container; otherwise, gas will be difficult to discharge.

[0046] In addition, the top of the slag discharge chamber of the water seal container is open, and on-site workers can take out the slag in time through the opening to avoid affecting the water seal effect.

[0047] Due to the continuous addition of water from the first dustproof nozzle 24, the flushing pipe 25 and the second dustproof nozzle 31, the water seal container is provided with an overflow port 34 and a drain port 35; in order to control the liquid level in the water seal container and ensure normal operation. As a specific implementation method, Figure 3 As shown, the height of the overflow port is higher than the bottom end of the water seal vertical plate and lower than the bottom end of the dust isolation plate 32.

[0048] For example, the gas collection bag 50 is also connected to the main pipe 10 via the third extraction sub-pipe 13. The design of the third extraction sub-pipe 13 allows the gas in the gas collection bag 50 to be discharged at an appropriate time. Moreover, when the gas pressure is particularly high, the third extraction sub-pipe 13 can be directly opened to discharge the gas.

Claims

1. An underground water-sealed gas blowout prevention system, characterized in that: It comprises an inner insert sleeve (60) arranged at the borehole mouth, wherein the outer end of the inner insert sleeve (60) is connected to a section of blowout prevention sleeve (21); The top of the blowout prevention casing (21) is connected to the main pipe (10) located at the top of the roadway through the first extraction sub-pipe (11); The bottom of the blowout prevention casing (21) is connected to a slag receiving box (23), and the bottom of the slag receiving box (23) is connected to a water seal container; wherein the area of the connection between the blowout prevention casing (21) and the first extraction sub-pipe (11) is smaller than the area of the connection between the blowout prevention casing (21) and the slag receiving box (23); A water seal plate (33) is provided in the water seal container, and the bottom end of the water seal plate (33) is located below the liquid level in the water seal container; the water seal plate (33) divides the inner cavity of the water seal container into a gas discharge cavity and a slag discharge cavity; The gas discharge chamber is connected to the main pipe via its first extraction port (36), and the gas discharge chamber is also connected to a gas collecting bag (50).

2. The underground water-sealed gas blowout prevention system according to claim 1, characterized in that: A first dustproof nozzle (24) is provided in the slag receiving box (23), and a liquid spraying port of the first dustproof nozzle (24) faces toward a connection port between the section of the blowout prevention sleeve (21) and the slag receiving box (23).

3. The underground water-sealed gas blowout prevention system according to claim 2, characterized in that: A flushing pipe (25) is provided in the slag receiving box (23), and the flushing pipe (25) faces the bottom outlet of the slag receiving box (23).

4. A downhole water-sealed gas blowout prevention system according to claim 2 or 3, characterized in that: The slag receiving box (23) is connected to the water seal container via a transmission pipe (40).

5. The underground water-sealed gas blowout prevention system according to claim 2, characterized in that: A second-stage blowout prevention casing (22) is further provided at the free end of the first-stage blowout prevention casing (21), and a spare slag receiving box (26) is provided at the bottom of the second-stage blowout prevention casing (22).

6. The underground water-sealed gas blowout prevention system according to claim 2, characterized in that: The gas discharge chamber is a closed chamber, and a first extraction port (36) and a second extraction port (38) are respectively provided on the top thereof; The first extraction port (36) is connected to the main pipe (10) through the second extraction sub-pipe (12); The second extraction port (38) is connected to an air collection bag (50).

7. The underground water-sealed gas blowout prevention system according to claim 6, characterized in that: A second dust-proof nozzle (31) is provided in the gas discharge chamber, and a liquid spraying port of the second dust-proof nozzle (31) faces toward a slag inlet (37) of the water seal container; The gas discharge chamber is also provided with a dust shielding plate (32) near the slag inlet (37). The dust shielding plate (32) extends downward from the top plate of the water seal container, and a gap is formed between the lower end thereof and the liquid surface in the water seal container.

8. The underground water-sealed gas blowout prevention system according to claim 7, characterized in that: The top of the slag discharge cavity is open.

9. The underground water-sealed gas blowout prevention system according to claim 8, characterized in that: The water seal container is provided with an overflow port (34) and a drain port (35); The height of the overflow port is higher than the bottom end of the water seal vertical plate and lower than the bottom end of the dust isolation plate (32).

10. The underground water-sealed gas blowout prevention system according to claim 6, characterized in that: The air collecting bag (50) is also connected to the main pipe (10) via a third extraction sub-pipe (13).

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