CN109826664B - An integrated device and method for coal seam gas extraction and borehole water automatic discharge - Google Patents

Abstract

The invention discloses an integrated device and a method for coal seam gas extraction and automatic drainage of accumulated water in a drill hole, wherein the device comprises a gas extraction system, a water guide system and a drainage system; the gas extraction system comprises an extraction pipe, a gas conveying pipeline and a connecting pipe, wherein one end of the extraction pipe is positioned in a gas extraction drill hole, and the other end of the extraction pipe is connected with the gas conveying pipeline through the connecting pipe; the water guide system comprises a water guide pipe, a filter residue sleeve and a water collecting tank, the upper end of the water guide pipe is connected with the extraction pipe, the lower end of the water guide pipe is connected with the water collecting tank, and the upper part of the water collecting tank is connected with the connecting pipe through a gas guide pipe; the drainage system comprises a drainage pipe, a drainage valve, a communicating pipe and an air pressure balance valve, wherein the drainage pipe is connected with the bottom of the water collection tank, and the communicating pipe is positioned at the lower port of the water guide pipe. According to the invention, the water guide system and the drainage system which are connected to the gas extraction system can realize automatic drainage of accumulated water in the gas extraction drilling hole while carrying out coal seam gas extraction, and the difficult problem of accumulated water in the gas extraction drilling hole of the water-rich coal seam can be effectively solved.

Description

An integrated device and method for coal seam gas extraction and borehole water automatic discharge

Technical field

The invention relates to the technical field of coal seam gas extraction and drilling equipment, and in particular to an integrated device and method for coal seam gas extraction and automatic discharge of borehole water.

Background technique

The gas content of coal seams in my country is generally high. More than 70% of state-owned coal mines are mines with high gas and coal and gas outbursts. The existence of gas has seriously affected the safe mining of coal mines. At present, the most common and effective technical means for mine gas control is coal seam Gas pre-pumping. Most coal seams not only contain a large amount of gas, but also contain a large amount of water. When gas is extracted from the coal seam, water in the coal seam easily flows into the gas extraction borehole, causing water accumulation in the negative pressure gas drainage pipeline. phenomenon, increasing the resistance in the negative pressure drainage pipeline, causing greater negative pressure loss, thus affecting the gas drainage efficiency. For water-rich coal seams with a large water content, a large amount of water in the coal seams pours into the gas drainage boreholes. When the water accumulation is severe, the gas drainage pipelines may be completely blocked, which not only causes the gas drainage boreholes to fail, but also affects the gas drainage. The extraction efficiency will also pose a huge threat to the safe operation of gas negative pressure extraction pumping stations.

At present, the technical measures and equipment to deal with the problem of water accumulation in coal seam gas drainage boreholes are mainly to connect a water release device to the gas drainage pipeline. The water that pours into the gas drainage borehole from the coal seam is discharged from the gas drainage pipeline through the water release device. discharge it. However, the currently commonly used gas drainage borehole water discharge devices cannot effectively discharge the accumulated water in the borehole, which is mainly manifested in the following two aspects: ① During normal gas extraction, the drainage pipeline is in a negative pressure state. Under the action of negative pressure, the accumulated water in the gas drainage borehole is difficult to be smoothly released through the water release device connected to the negative pressure drainage pipeline, and may also cause a loss of negative pressure in the drainage, affecting normal gas drainage operations; ② Gas drainage A large amount of coal dust will be produced during the drilling process. At the same time, the deformation and collapse of the coal wall after the drilling is completed will also produce coal dust and larger coal particles. In addition, the water flowing into the gas drainage borehole will cause the coal dust to disappear. The debris flows into the water drainage device with the accumulated water, which can easily cause the water drainage device to become clogged and make it difficult to clean. In addition, in recent years, there have been reports in the literature about the use of a pneumatic borehole water discharge device, but this device is only suitable for downward gas drainage boreholes and cannot be used to discharge accumulated water in the coal seam gas drainage boreholes, and this device The system is complex and costly. Therefore, in view of the current problems such as water accumulation in gas drainage boreholes and poor drainage device effectiveness, it is urgent to develop a reliable and effective integrated device and method for coal seam gas extraction and automatic drainage of borehole water accumulation.

Contents of the invention

The object of the present invention is to overcome the shortcomings of existing gas drainage borehole water discharge equipment and discharge methods, and provide an integrated device and method for coal seam gas extraction and borehole water automatic discharge, so as to achieve effective discharge of coal seam gas extraction borehole water. , to overcome the shortcomings of coal dust clogging drainage pipelines in the discharge of water from boreholes, thereby effectively ensuring the service cycle of gas drainage boreholes and improving borehole gas drainage efficiency.

In order to achieve the above objects, the present invention adopts the following technical solutions:

An integrated device for coal seam gas extraction and borehole water automatic discharge, including a gas extraction system, a water conduction system and a drainage system; the gas extraction system includes a extraction pipe, a gas transmission pipeline, a connecting pipe, and a drainage pipe One end is located in the gas drainage borehole, and the other end is connected to the gas transmission pipeline through a connecting pipe; the water conduit system includes a water conduit pipe, a filter casing, and a water collection tank. The upper end of the water conduit pipe is connected to the drainage pipe, and the lower end is connected to the water collection tank. The upper part of the water collecting tank is connected to the connecting pipe through the air guide pipe; the drainage system includes a drainage pipe, a drainage valve, a connecting pipe, and an air pressure balance valve. The drainage pipe is connected to the bottom of the water collecting tank, and the connecting pipe is located at the lower port of the water pipe.

One end of the extraction pipe passes through the hole sealing section and is inserted into the gas drainage borehole, and the other end is connected to the connecting pipe and the water conduit pipe through a tee, and the water conduit pipe is located below the connecting pipe.

Both ends of the connecting pipe are connected to the extraction pipe and the gas transportation pipeline respectively. The gas in the coal seam enters the gas transportation pipeline from the gas extraction borehole under negative pressure through the extraction pipe and the connecting pipe.

The water conduit pipe extends vertically downward from the outlet of the extraction pipe, and is connected to the water conduit valve, filter casing, and water flow meter from top to bottom. The lower end of the water conduit pipe is connected to the upper port of the water collection tank, and is connected to the water collection tank. A connecting pipe is connected to the water conduit between the water flow meter and the water flow meter; one end of the communicating pipe is connected to the water conduit, and the other end is directly connected to the atmosphere, and the communicating pipe is provided with an air pressure balance valve.

The filter residue casing is a hollow circular tube with a filter inside, and the filter residue casing is connected to the water conduit through quick connectors at both ends.

The upper interface of the water collection tank is connected to the air guide pipe, and the bottom interface is connected to the drainage pipe; the drainage pipe is provided with a drainage valve, and the discharge of the borehole water collected in the water collection tank is controlled through the drainage valve.

The upper end of the air guide pipe is connected to the connecting pipe, the lower end is connected to the upper port of the water collection tank, and the air guide pipe is provided with a tracheal valve.

Based on the integrated method of coal seam gas drainage and automatic discharge of borehole water, it includes the following steps:

a. Borehole layout: First, drill a gas drainage borehole with a certain depth and upward angle in the coal seam according to the set borehole layout parameters, clean the coal debris in the gas drainage borehole, and then drain the gas. The pipe is inserted into the gas drainage borehole, and the gas drainage borehole is sealed so that one end of the drainage pipe passes through the hole sealing section and is inside the gas drainage borehole, and the other end is inside the mine tunnel;

b. Component assembly: First, connect one end of the extraction pipe in the tunnel to the connecting pipe and the water conduit pipe through a tee. One end of the connecting pipe is connected to the upper end of the tee, and the other end is connected to the gas transportation pipeline. Then connect the water conduit pipe. At the lower end of the tee, connect the water conduction valve, filter casing, and water flow meter in sequence from top to bottom in the vertical direction. The lower end of the water conduction pipe is connected to the upper port of the water collection tank, and then the connecting pipe is connected to the water collection tank and the water flow meter. on the water conduit pipe between the flowmeters, and install a pressure balance valve on the connecting pipe. Finally, connect the upper interface of the water collection tank to the air conduit pipe. The other end of the air conduit pipe is connected to the connecting pipe, and a tracheal valve is installed on the air conduit pipe. At the same time, connect the bottom interface of the water collection tank to the drainage pipe, and install a drainage valve on the drainage pipe;

c. Gas drainage and water diversion: After all components and pipelines are connected, open the air pipe valve and water diversion valve, close the drainage valve and air pressure balance valve, and perform negative pressure extraction of the gas in the coal seam. At this time, the gas is drained. The air pressure in the borehole is equal to the air pressure in the water collection tank. During gas extraction, the accumulated water in the gas extraction borehole automatically flows into the water collection tank through the water pipe under the action of gravity for collection. When the gas When the large particles of coal dust in the extraction borehole flow into the water conduit pipe along with the accumulated water in the borehole and accumulate in the filter residue casing, after closing the air pipe valve and the water conduction valve, remove the filter residue casing from the water conduit pipe, and clean the filter residue casing. Clean the coal dust, and then reinstall the filter casing on the water conduit. During this coal dust cleaning process, gas drainage continues without interruption;

d. Discharge of accumulated water: Regularly check the indication of the water flow meter on the water conduit pipe. When the indication of the cumulative flow on the water flow meter reaches 80% of the total capacity of the water collection tank, close the air pipe valve and water conduit valve, and open the drainage at the same time. The valve and air pressure balance valve make the air pressure in the water collection tank equal to the external atmospheric pressure. At this time, the water in the water collection tank is discharged along the drainage pipe at the bottom of the water collection tank under the action of gravity. The entire drilling water discharge process does not affect the gas. Drainage, gas drainage and borehole water discharge operations can be carried out simultaneously without affecting each other.

Beneficial effects of the present invention:

1. The present invention connects the connecting pipe to the water collection tank through the air guide pipe, so that the air pressure in the water collection tank is equal to the air pressure in the gas extraction pipeline, and the accumulated water in the gas extraction borehole can pass through under the action of gravity. The water pipe automatically flows into the water collection tank for collection, which avoids the disadvantage that water accumulated in the gas drainage borehole cannot be discharged smoothly due to the influence of negative pressure;

2. The present invention cleans out the coal dust that flows out along with the accumulated water in the gas extraction borehole by arranging a filter residue casing that is easy to disassemble on the upper part of the water conduit pipe, which can effectively prevent the coal dust from clogging the borehole water discharge device, and also prevents coal dust from clogging the borehole water discharge device. During the chip cleaning process, the gas drainage operation can be continued without interruption;

3. The present invention can realize the entire borehole water discharge process without affecting the coal seam gas drainage operation. The gas extraction and borehole water discharge operations can be carried out simultaneously without affecting each other. In addition, the present invention can solve the problem of water accumulation in the gas negative pressure drainage pipeline. At the same time, it also effectively eliminates the adverse effects of water accumulation and cinder on gas drainage boreholes, effectively extends the service time of gas drainage boreholes, and improves gas drainage efficiency.

Description of the drawings

Figure 1 is a schematic structural diagram of an integrated device for coal seam gas extraction and borehole water automatic discharge according to the present invention;

In the picture: 1-coal seam; 2-gas drainage borehole; 3-drainage pipe; 4-hole sealing section; 5-gas transmission pipeline; 6-connecting pipe; 7-gas pipe; 8-gas pipe valve; 9 - Drainage pipe; 10 - Drainage valve; 11 - Water conduit pipe; 12 - Water conduit valve; 13 - Filter casing; 14 - Water flow meter; 15 - Connecting pipe; 16 - Air pressure balance valve; 17 - Water collection tank.

Detailed ways

The specific implementation manner of the present patent will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, an integrated device for coal seam gas extraction and borehole water automatic discharge includes a gas extraction system, a water diversion system and a drainage system; the gas extraction system includes a extraction pipe 3, a gas transportation pipeline 5. Connecting pipe 6, one end of the extraction pipe 3 is located in the gas extraction borehole 2, and the other end is connected to the gas transportation pipeline 5 through the connecting pipe 6; the water conduit system includes a water conduit 11, a filter casing 13, and a water collection tank. 17. The upper end of the water conduit pipe 11 is connected to the extraction pipe 3, and the lower end is connected to the water collecting tank 17. The upper part of the water collecting tank 17 is connected to the connecting pipe 6 through the air conduit pipe 7; the drainage system includes a drainage pipe 9, a drainage valve 10, and a connecting pipe 15. , the air pressure balance valve 16, the drainage pipe 9 is connected to the bottom of the water collecting tank 17, and the connecting pipe 15 is located at the lower port of the water conduit 11.

One end of the extraction pipe 3 passes through the hole sealing section 4 and is inserted into the gas extraction borehole 2, and the other end is connected to the connecting pipe 6 and the water conduit pipe 11 through a tee, and the water conduit pipe 11 is located below the connecting pipe 6 to ensure that The gas gas flows upward into the gas transportation pipeline 5, while the accumulated water in the gas extraction borehole 2 flows into the water collection tank 17 along the water conduit 11; the two ends of the connecting pipe 6 are connected to the extraction pipe 3 and the gas transportation pipeline 5 respectively. connection, the gas in the coal seam 1 enters the gas transportation pipeline 5 from the gas extraction borehole 2 through the extraction pipe 3 and the connecting pipe 6 under negative pressure; the water conduit pipe 11 is vertically connected from the outlet of the extraction pipe 3 to Extend downward and connect the water diversion valve 12, filter residue casing 13, and water flow meter 14 in sequence from top to bottom. The lower end of the water diversion pipe 11 is connected to the upper port of the water collection tank 17, and is between the water collection tank 17 and the water flow meter 14. A connecting pipe 15 is connected to the water pipe 11; one end of the connecting pipe 15 is connected to the water pipe 11, and the other end is directly connected to the atmosphere, and the connecting pipe 15 is provided with an air pressure balance valve 16, which controls the water collecting tank 17. When the water is discharged, the air pressure balance valve 16 is opened to ensure that the air pressure in the water collection tank 17 is equal to the external atmospheric pressure, so that the water in the water collection tank 17 can be smoothly discharged under the action of gravity.

The filter residue casing 13 is a hollow circular tube with a filter inside, and the filter residue casing 13 is connected to the water conduit 11 through the quick connectors at both ends. The filter residue casing 13 can collect water in the gas drainage borehole. The coal dust flowing out together is filtered and cleaned out, which can effectively prevent the coal dust from clogging the borehole water discharge device, and the gas extraction operation can be continued during the coal dust cleaning process without interruption; the upper interface of the water collection tank 17 is connected with the guide The air pipe 7 is connected, and the bottom interface is connected to the drainage pipe 9; the drainage pipe 9 is provided with a drainage valve 10, and the discharge of the borehole water collected in the water collection tank 17 is controlled through the drainage valve 10; the upper end of the air guide pipe 7 is connected to The pipe 6 is connected, and the lower end is connected to the upper port of the water collecting tank 17, and the air pipe 7 is provided with a tracheal valve 8; when performing gas extraction operations, the connecting pipe 6 is connected to the upper port of the water collecting tank 17 through the air pipe 7 , so that the air pressure in the water collection tank 17 is equal to the air pressure in the gas extraction pipeline, and the accumulated water in the gas extraction borehole 2 can automatically flow into the water collection tank 17 through the water conduit 11 under the action of gravity for collection. It avoids the disadvantage that the water accumulated in the gas drainage borehole cannot be drained smoothly due to the influence of the negative pressure of the gas drainage.

Based on the integrated method of coal seam gas extraction and borehole water automatic discharge, the above-mentioned integrated coal seam gas extraction and borehole water automatic discharge integrated device includes the following steps:

a. Borehole layout: First, drill a gas drainage borehole 2 with a certain depth and upward angle in the coal seam 1 according to the set borehole layout parameters, and clean the coal cuttings in the gas drainage borehole 2, and then Insert the drainage pipe 3 into the gas drainage borehole 2, and seal the gas drainage borehole 2 so that one end of the drainage pipe 3 passes through the sealing section 4 and is inside the gas drainage borehole 2, and the other end is in the mine. in the lane;

b. Component assembly: First, connect one end of the extraction pipe 3 in the tunnel to the connecting pipe 6 and the water conduit pipe 11 through a tee. One end of the connecting pipe 6 is connected to the upper end of the tee, and the other end is connected to the gas transportation pipeline 5. Then connect the water conduit 11 to the lower end of the tee, and connect the water conduit valve 12, filter residue sleeve 13, and water flow meter 14 from top to bottom in the vertical direction. The lower end of the water conduit 11 is connected to the upper port of the water collection tank 17. Then connect the connecting pipe 15 to the water pipe 11 between the water collecting tank 17 and the water flow meter 14, and install the air pressure balance valve 16 on the connecting pipe 15. Finally, connect the upper interface of the water collecting tank 17 to the air pipe 7. The other end of the air guide pipe 7 is connected to the connecting pipe 6, and the air pipe valve 8 is installed on the air guide pipe 7. At the same time, the bottom interface of the water collection tank 17 is connected to the drainage pipe 9, and the drainage valve 10 is installed on the drainage pipe 9;

c. Gas extraction and water diversion: After all components and pipelines are connected, open the gas pipe valve 8 and the water diversion valve 12, close the drainage valve 10 and the air pressure balance valve 16, and perform negative pressure extraction of the gas in the coal seam. At this time, the air pressure in the gas extraction borehole 2 is equal to the air pressure in the water collection tank 17. While gas extraction is being carried out, the accumulated water in the gas extraction borehole 2 automatically flows into the collection tank through the water conduit 11 under the action of gravity. Collect in the water tank 17. When the large coal dust in the gas extraction borehole 2 flows into the water conduit 11 with the accumulated water in the borehole and accumulates in the filter residue casing 13, after closing the gas pipe valve 8 and the water conduit valve 12, the filter residue The casing 13 is removed from the water conduit 11, the coal dust in the filter slag casing 13 is cleaned, and then the filter slag casing 13 is reinstalled on the water conduit 11. During this coal slag cleaning process, gas drainage continues without interruption. ;

d. Discharge of accumulated water: Regularly check the indication of the water flow meter 14 on the water conduit 11. When the indication of the cumulative flow on the water flow meter 14 reaches 80% of the total capacity of the water collection tank 17, close the air pipe valve 8 and the water conduit. Valve 12, open the drainage valve 10 and the air pressure balance valve 16 at the same time, so that the air pressure in the water collection tank 17 is equal to the external atmospheric pressure. At this time, the water in the water collection tank 17 flows along the drainage pipe at the bottom of the water collection tank 17 under the action of gravity. 9 is discharged, the entire borehole water discharge process will not affect gas drainage. Gas drainage and borehole water discharge operations can be carried out simultaneously without affecting each other.

The above are only preferred embodiments of the present invention, and are not limited to the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention, such as changing the shape of the water collecting tank and Materials, changing the relative positions of the air conduit and the communication tube, etc. should all be included in the protection scope of the present invention.

Claims (7)

1. Based on the integrated method of coal seam gas extraction and borehole water automatic discharge, an integrated device for coal seam gas extraction and borehole water automatic discharge is used, which is characterized in that: the device includes a gas extraction system, a water diversion system and a drainage system. System; the gas drainage system includes a drainage pipe, a gas transportation pipeline, and a connecting pipe. One end of the drainage pipe is located in the gas drainage borehole, and the other end is connected to the gas transportation pipeline through the connecting pipe; the water guiding system includes a gas guiding pipe. Water pipe, filter residue casing, water collection tank, the upper end of the water conduit pipe is connected to the extraction pipe, the lower end is connected to the water collection tank, the upper part of the water collection tank is connected to the connecting pipe through the air guide pipe; the drainage system includes drainage pipes, drainage valves, connecting pipes, The air pressure balance valve, the drainage pipe is connected to the bottom of the water collection tank, and the connecting pipe is located at the lower port of the water conduit pipe. The method includes the following steps: a. Borehole layout: First, drill a gas drainage borehole with a certain depth and upward angle in the coal seam according to the set borehole layout parameters, clean the coal debris in the gas drainage borehole, and then drain the gas. The pipe is inserted into the gas drainage borehole, and the gas drainage borehole is sealed so that one end of the drainage pipe passes through the hole sealing section and is inside the gas drainage borehole, and the other end is inside the mine tunnel; b. Component assembly: First, connect one end of the extraction pipe in the tunnel to the connecting pipe and the water conduit pipe through a tee. One end of the connecting pipe is connected to the upper end of the tee, and the other end is connected to the gas transportation pipeline. Then connect the water conduit pipe. At the lower end of the tee, connect the water conduction valve, filter casing, and water flow meter in sequence from top to bottom in the vertical direction. The lower end of the water conduction pipe is connected to the upper port of the water collection tank, and then the connecting pipe is connected to the water collection tank and the water flow meter. on the water conduit pipe between the flowmeters, and install a pressure balance valve on the connecting pipe. Finally, connect the upper interface of the water collection tank to the air conduit pipe. The other end of the air conduit pipe is connected to the connecting pipe, and a tracheal valve is installed on the air conduit pipe. At the same time, connect the bottom interface of the water collection tank to the drainage pipe, and install a drainage valve on the drainage pipe; c. Gas drainage and water diversion: After all components and pipelines are connected, open the air pipe valve and water diversion valve, close the drainage valve and air pressure balance valve, and perform negative pressure extraction of the gas in the coal seam. At this time, the gas is drained. The air pressure in the borehole is equal to the air pressure in the water collection tank. During gas extraction, the accumulated water in the gas extraction borehole automatically flows into the water collection tank through the water pipe under the action of gravity for collection. When the gas When the large particles of coal dust in the extraction borehole flow into the water conduit pipe along with the accumulated water in the borehole and accumulate in the filter residue casing, after closing the air pipe valve and the water conduction valve, remove the filter residue casing from the water conduit pipe, and clean the filter residue casing. Clean the coal dust, and then reinstall the filter casing on the water conduit. During this coal dust cleaning process, gas drainage continues without interruption; d. Discharge of accumulated water: Regularly check the indication of the water flow meter on the water conduit pipe. When the indication of the cumulative flow on the water flow meter reaches 80% of the total capacity of the water collection tank, close the air pipe valve and water conduit valve, and open the drainage at the same time. The valve and air pressure balance valve make the air pressure in the water collection tank equal to the external atmospheric pressure. At this time, the water in the water collection tank is discharged along the drainage pipe at the bottom of the water collection tank under the action of gravity. The entire drilling water discharge process does not affect the gas. Drainage, gas drainage and borehole water discharge operations are carried out simultaneously and do not affect each other. 2. The integrated method of coal seam gas extraction and borehole water automatic discharge according to claim 1, characterized in that: one end of the extraction pipe passes through the hole sealing section and is inserted into the gas extraction borehole, and the other end passes through three The pipes are respectively connected to the connecting pipe and the water conduit pipe, and the water conduit pipe is located below the connecting pipe. 3. The integrated method based on coal seam gas extraction and borehole water automatic discharge according to claim 2, characterized in that: both ends of the connecting pipe are connected to the extraction pipe and the gas transportation pipeline respectively, and the gas in the coal seam is in Under negative pressure, the gas drainage borehole enters the gas transportation pipeline through the drainage pipe and connecting pipe. 4. The integrated method of coal seam gas extraction and borehole water automatic discharge according to claim 2, characterized in that: the water conduit pipe extends vertically downward from the outlet of the extraction pipe, and is connected to the conduit pipe in sequence from top to bottom. Water valve, filter residue casing, water flow meter, the lower end of the water conduit pipe is connected to the upper port of the water collection tank, and a connecting pipe is connected to the water conduit pipe between the water collection tank and the water flow meter; one end of the connecting pipe is connected to the water conduit pipe connected, the other end is directly connected to the atmosphere, and the connecting pipe is provided with a pressure balance valve. 5. The integrated method of coal seam gas extraction and borehole water automatic discharge according to claim 4, characterized in that: the filter residue casing is a hollow circular tube with a filter screen inside, and the filter residue casing passes through both sides of it. The quick connector at the end is connected to the water pipe. 6. The integrated method based on coal seam gas extraction and automatic discharge of borehole water according to claim 4, characterized in that: the upper interface of the water collection tank is connected to the air guide pipe, and the bottom interface is connected to the drainage pipe; the drainage pipe There is a drainage valve on the top, and the discharge of the borehole water collected in the water collection tank is controlled through the drainage valve. 7. The integrated method of coal seam gas extraction and borehole water automatic discharge according to claim 6, characterized in that: the upper end of the air guide pipe is connected to the connecting pipe, the lower end is connected to the upper port of the water collection tank, and the air guide pipe is connected to the upper port of the water collection tank. The trachea is provided with a tracheal valve.