Flooded closed water-gas separation system

Abstract

This invention discloses a flooded water-gas separation system. The system includes a blowout preventer installed at the borehole opening to seal the borehole opening and prevent water and gas from entering the roadway. A mixing discharge pipe is connected to the sidewall of the borehole, and the outlet of the mixing discharge pipe is connected to the water-gas separation device. The mixing discharge pipe introduces the water and gas mixture into the water-gas separation device, which separates the mixture into water and gas. The water-gas separation device includes a vertically arranged straight pipe, the upper part of which is connected to an exhaust pipe, the middle part to the outlet of the mixing discharge pipe, and the lower part extending below the water surface. This invention can effectively separate water and gas when encountering a water-gas mixture during hydrogeological drilling in a coal mine track roadway.

Description

[Technical field]

[0001] The invention belongs to the technical field of coal mine equipment, and in particular relates to a flooded water-gas separation system. [Background technology]

[0002] During coal mining, various geological conditions will be encountered. When there is an Ordovician limestone stratum under the coal seam and the distance is relatively close, such as 8 to 20 meters, it is generally more threatened by Ordovician limestone water. It is necessary to study and demonstrate the hydrogeological conditions and evaluate the mining hydrogeological conditions based on the drilling results.

[0003] When conducting research and demonstration on hydrogeological conditions, it is necessary to conduct hydrogeological drilling construction in the track tunnel of a coal mine. It is very likely to encounter problems such as water and gas mixed gushing and excessive gas concentration in the drilling field, which seriously threaten the safety of the mine. Although the conventional grouting method can block the water, it is difficult to block the gas. In severe cases, it will cause the borehole to be scrapped and construction to be stopped. [Summary of the invention]

[0004] The purpose of the present invention is to provide a water-flooded water-gas separation device, so as to effectively separate water and gas when water and gas mixed and gushed out during hydrogeological drilling construction in a track lane of a coal mine.

[0005] The present invention adopts the following technical scheme: a flooded water-gas separation system, comprising an orifice blowout prevention device installed at the orifice of a borehole, the orifice blowout prevention device being used to seal the orifice of the borehole to prevent water and gas from pouring into the tunnel;

[0006] A mixing discharge pipe is connected to the side wall of the borehole, and the outlet of the mixing discharge pipe is connected to a water-gas separation device. The mixing discharge pipe is used to introduce the water and gas mixture into the water-gas separation device, and the water-gas separation device is used to separate the water and gas mixture into water and gas; the water-gas separation device includes a vertically arranged straight pipe, the upper part of the straight pipe is connected to the exhaust pipe, the middle part is connected to the outlet of the mixing discharge pipe, and the lower part extends below the water surface.

[0007] Furthermore, the orifice blowout prevention device comprises an orifice flange installed at the orifice, an orifice cover plate is installed on the orifice flange, and a sealing interlayer is also arranged between the orifice flange and the orifice cover plate.

[0008] Furthermore, a drilling tee is installed on the side wall of the drilling hole near the hole opening, two opposite ports of the drilling tee are arranged in the drilling hole, and the other port of the drilling tee is sealed and connected to the mixed discharge pipeline.

[0009] Furthermore, a master control valve is installed on the mixed discharge pipeline.

[0010] Furthermore, a pressure gauge is installed on the exhaust pipe.

[0011] Furthermore, an automatic air intake and exhaust valve group is installed on the exhaust pipe.

[0012] Furthermore, a regulating valve is provided at the upper end of the straight pipe.

[0013] The beneficial effects of the present invention are as follows: the present invention designs and applies an orifice blowout prevention device, a water-gas separation device and an exhaust pipe, the orifice blowout prevention device is used to prevent water and gas from gushing out of the orifice, the water and gas are separated by the water-gas separation device, and the gas is sent out through the exhaust pipe, and comprehensive treatment is carried out, the effect is very obvious, and the expected purpose is achieved. At the same time, not only the mine coal bottom plate Ordovician ash hydrogeological exploration drilling project is safely and effectively progressed, but also continuous gas is provided for the gas power plant, the power generation is increased, thereby turning waste into treasure, and the technical and economic benefits are obvious.

Brief Description of the Drawings

[0014] Figure 1 It is a structural schematic diagram of the present invention;

[0015] Figure 2 It is a schematic diagram of the structure of the orifice blowout prevention device in the present invention.

[0016] Among them: 1. Pressure gauge; 2. Automatic suction and exhaust valve group; 3. Exhaust pipeline; 4. Water surface; 5. Regulating valve; 6. Master control valve; 7. Orifice blowout preventer; 8. Mixed discharge pipeline; 9. Drilling hole; 10. Straight pipe; 11. Filling / draining valve; 12. Drilling tee; 13. Orifice flange; 14. Orifice cover plate. [Specific implementation method]

[0017] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The present invention discloses a water-flooded water-gas separation system, such as Figure 1 As shown, it includes an orifice blowout prevention device 7 installed at the orifice of the borehole 9. The orifice blowout prevention device 7 is mainly used to prevent gas from being ejected from the drill tool and the outer ring of the drill tool. In view of the problem of gas ejecting from the drill tool during the drilling process, a one-way valve is installed between the core tube and the drill tool using the principle of a one-way valve to prevent gas from being ejected. In addition, the drill pipe thread may also be gas inlet, and a polytetrafluoroethylene oil-free sealing tape is wound around the drill pipe thread to effectively seal it. By applying the above comprehensive measures, the purpose of preventing high-concentration gas from gushing out of the drill tool is achieved.

[0019] The outer ring of the drill tool is the channel for the drilling tool flushing fluid to return to the borehole. When the flushing fluid containing high-concentration gas returns to the orifice without control, the high-concentration gas will naturally escape to the drilling site, posing a serious safety hazard. In order to eliminate this hazard, a drilling tee 12 is added above the orifice valve, and a wear-resistant orifice blowout preventer 7 that can pass through drill tools of different diameters frequently. The drill tool passes through the middle of the orifice sealing pad to prevent gas from overflowing from the outer ring of the drill tool during drilling and drilling. Figure 2 As shown, the orifice blowout prevention device 7 is used to seal the orifice of the borehole 9 to prevent water and gas from flowing into the tunnel. The orifice blowout prevention device 7 includes an orifice flange 13 installed at the orifice, an orifice cover plate 14 is installed on the orifice flange 13, a sealing interlayer is also arranged between the orifice flange 3 and the orifice cover plate 14, and a through hole for the drilling tool to pass through is arranged on the orifice cover plate 14, and the sealing interlayer is used to realize the sealing of the outer ring of the drilling tool.

[0020] Meanwhile, in this embodiment, a through hole of the drilling tee 12 is connected to the water-gas separation device by using a 4-inch valve and a Φ108 pipe, and the gas and flushing liquid in the hole are introduced from the mixed discharge pipe 8 into the water-gas separation device for separation, that is, a drilling tee 12 is installed on the side wall near the hole opening of the drilling tee 12, and two opposite ports of the drilling tee 12 are arranged in the drilling tee 9, and the other port of the drilling tee 12 is sealed and connected to the mixed discharge pipe 8. The mixed discharge pipe 8 is connected to the side wall of the drilling tee 9, and the mixed discharge pipe 8 is used to introduce the water and gas mixture into the water-gas separation device, and the mixed discharge pipe 8 is installed with a master control valve 6.

[0021] The outlet of the mixed discharge pipeline 8 is connected to a water-gas separation device, and the water outlet and gas outlet of the water-gas separation device are connected to a supply / drainage pipeline and an exhaust pipeline 3 respectively.

[0022] The water-gas separation device is used to separate the water-gas mixture into water and gas. The water-gas separation device can greatly reduce the difficulty of workers' operation and eliminate the risk of pumping water. The water-gas separation device includes a vertically arranged straight pipe 10, the upper part of which is connected to the exhaust pipe 3, the middle part is connected to the outlet of the mixed discharge pipe 8, and the lower part extends below the water surface 4. A regulating valve 5 is arranged at the upper end of the straight pipe 10. A pressure gauge 1 is installed on the exhaust pipe 3, and an automatic suction and exhaust valve group 2 is installed on the exhaust pipe 3.

[0023] The working principle of the water-gas separation device is that the blowout prevention device added to the orifice will pressure more than 90% of the mixed water and gas gushing out of the borehole into the water-gas separation device located in a special water pool.

[0024] The water and gas entering the water-gas separation device are naturally separated by different specific gravities at the outlet of the mixed discharge pipeline 8. The gas rising naturally to the upper part of the straight pipe 10 is introduced into the gas pipe and evacuated through the exhaust pipeline 3 connected to the upper part of the straight pipe 10 and the automatic suction and exhaust valve group 2 (ensuring the pressure balance inside and outside the straight pipe 10 - 0.1 MPa). The separated water and rock powder fall into the water tank by their own weight, and the liquid level in the tank always remains submerged below the lower edge of the straight pipe 10 (the submerged height reaches 5 - 20 cm), which can play a sealing role. The excess water is introduced from the water tank into other water tanks.

[0025] This device works based on the principle of separating the gas inside and outside the water-gas separation device in the water tank and transmitting pressure, and controlling the gas volume in the straight pipe 10 to be equal to the gas emission volume by manually opening and closing the valves, so as to ensure the dynamic balance between the air pressure in the straight pipe 10 and the atmospheric pressure in the roadway.

[0026] The key point of the air extraction pressure control is to try to evacuate all the gas emitted and introduced into the straight pipe 10.

[0027] If Q_emission > Q_extraction, that is, the gas emission volume from the hole gradually increases and cannot be completely evacuated, then gas can be seen emerging from the water tank. At this time, it is necessary to adjust the automatic suction and exhaust valve group 2 to increase the gas extraction volume.

[0028] If Q_emission < Q_extraction, that is, the gas emission volume from the hole decreases, then the extraction air volume is greater than the emission volume. It can be seen that the liquid level in the water tank drops (the liquid level in the straight pipe 10 rises), and there may be a water pumping phenomenon. At this time, there are three solutions: ⑴ Using a buoyancy ball with a push rod and a gravity valve can prevent water absorption. ⑵ Reducing the masking height can naturally prevent water absorption due to air intake when the liquid level in the tank drops to the bottom edge of the straight pipe 10. ⑶ Adding an adjustment valve 5 to the straight pipe 10 and manually opening the valve when the liquid level drops can prevent water absorption.

[0029] If Q_emission = Q_discharge, that is, the extraction air volume is equal to the emission volume, it means that the emission-extraction balance has been established and drilling can begin.

[0030] Generally, the commonly used valve for the gas drainage pipe is a plate gate valve, and its adjustment mechanism is a tooth-type positioning, which is very difficult to accurately adjust the volume. As a result, the extraction and discharge volume is slightly greater than the gas emission volume from the drilling hole. In order not to pump the water in the straight pipe 10 into the pipeline, a small opening is manually opened at the adjustment valve 5 located at the top of the straight pipe 10 to supplement a small amount of air to establish balance, and finally the emission-extraction balance is achieved, and the commissioning is successfully completed.

[0031] In order to further achieve automatic adjustment of balance, an automatic suction and exhaust valve group 2 with two one-way ball valves, one above the other, can be added to the exhaust pipeline 3 in front of the valve at the upper part of the straight pipe 10 for automatic air intake and exhaust, which can achieve dynamic automatic balance and eliminate the hidden danger of pumping water.

[0032] The elevation of the borehole for hydrogeological exploration of Ordovician coal mine is 196.361. When drilling to 18m, the water in the hole is 1.5m 3 / h, the water pressure was 0.3MPa, and when drilling continued to 37.97m (close to the coal seam), water and gas mixed and gushed out, and the gas pressure was 0.52MPa. The gas concentration in the drilling site exceeded the limit, posing a serious safety hazard, and drilling was forced to stop. The mine decided to connect the hole to the gas extraction system for drainage, and drill a new hole 2m away from the hole. When the new hole was drilled to 18m, water came out again. When drilling to 33.2m, water and gas mixed and gushed out again. The gas pressure was 0.56MPa, and the concentration was seriously exceeded. Drilling was forced to stop again, and grouting was taken. After the grouting solidified, it was found that the water had been blocked when preparing to drill the hole, but high-concentration gas continued to gush out. The drilling rig was forced to move to other drilling sites to construct other boreholes, but the hole was also forced to stop drilling due to gas gushing when it was drilled to 20m. Finally, the water-flooded closed water-gas separation system of the present invention is used for treatment, which is effective on the spot. The gas is sent to the gas power plant through the exhaust pipe 3, and the water is discharged through the drainage pipe, thus achieving comprehensive treatment.

Claims

1. A flooded water-gas separation system, characterized in that: It comprises a borehole blowout prevention device (7) installed at the borehole (9), wherein the borehole blowout prevention device (7) is used to seal the borehole (9) to prevent water and gas from flowing into the tunnel; A mixing discharge pipe (8) is connected to the side wall of the borehole (9), and the outlet of the mixing discharge pipe (8) is connected to a water-gas separation device. The mixing discharge pipe (8) is used to introduce the water and gas mixture into the water-gas separation device, and the water-gas separation device is used to separate the water and gas mixture into water and gas. The water-gas separation device comprises a vertically arranged straight pipe (10), the upper part of the straight pipe (10) is connected to the exhaust pipe (3), the middle part is connected to the outlet of the mixing discharge pipe (8), and the lower part extends below the water surface (4); The exhaust pipe (3) is provided with an automatic air intake and exhaust valve group (2) having two upper and lower one-way ball valves; the upper end of the straight pipe (10) is provided with a regulating valve (5); The exhaust pressure control of the automatic air intake and exhaust valve group (2) comprises: If the amount of gas gushing out of the hole gradually increases and cannot be completely pumped out, gas gushing out can be seen in the water pool. In this case, the automatic air intake and exhaust valve group (2) should be adjusted to increase the amount of gas to be pumped out. If the gas outflowing from the hole decreases and the air extraction volume is greater than the outflowing volume, it can be seen that the liquid level in the pool drops. A regulating valve (5) is added to the straight pipe (10) and the regulating valve (5) is opened when the liquid level drops. If the exhaust volume is equal to the outflow volume, it means that the inflow-extraction balance has been established and drilling can begin.

2. The water-flooded water-gas separation system according to claim 1, characterized in that: The orifice blowout prevention device (7) comprises an orifice flange (13) installed at the orifice, an orifice cover plate (14) is installed on the orifice flange (13), and a sealing interlayer is provided between the orifice flange (13) and the orifice cover plate (14).

3. The flooded water-gas separation system according to claim 2, characterized in that: A drilled tee (12) is installed on the side wall of the drilled hole (9) near the orifice, two opposite ports of the drilled tee (12) are arranged in the drilled hole (9), and the other port of the drilled tee (12) is sealedly connected to the mixed discharge pipe (8).

4. The water-flooded water-gas separation system according to claim 2 or 3, characterized in that: A master control valve (6) is installed on the mixed discharge pipeline (8).

5. The flooded water-gas separation system according to claim 4, characterized in that: A pressure gauge (1) is installed on the exhaust pipe (3).

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