A continuous multiple sealing device and sealing method

Abstract

The application discloses a continuous multiple sealing device and sealing method, which comprises two bone-shaped sleeves, a gas extraction pipeline and a multi-zone grouting pipe sleeved on the two bone-shaped sleeves, and the multi-zone grouting pipe is communicated with a grouting device and a water pressurizing device through a connecting pipeline. First, the two bone-shaped sleeves are inflated by water suction to drill holes by controlling the water pressurizing device and the water outlet electric control valve, then the controller controls three grouting outlet electric control valves, and the grouting device and the water pressurizing device are opened and closed to complete the sealing of the sealing area one and empty the residual grouting material in the multi-zone grouting pipe, after the grouting material is solidified, gas extraction operation is carried out, when the gas extraction concentration is reduced to 4%, the above operation is repeated, and the sealing area two and the sealing area three are sequentially filled, and secondary and tertiary gas extraction operations are completed. The device can realize multiple sealing of the drilling hole, prolong the service life of the drilling hole and improve the gas extraction efficiency.

Description

Technical Field

[0001] This invention belongs to the field of mine gas extraction, and particularly relates to a continuous multiple sealing device and sealing method. Background Technology

[0002] Methane gas is both the root cause of coal mine gas explosions and a clean energy source. Efficient extraction and utilization of mine gas can not only effectively prevent gas disasters but also greatly alleviate my country's energy shortage. The quality of borehole sealing is crucial to gas extraction efficiency. Insufficient gas concentration will prevent utilization. However, current technologies often only allow for single or double sealing, not multiple sealing, thus affecting borehole lifespan and consequently gas extraction efficiency.

[0003] Therefore, in order to solve the problem of short service life of current coal mine gas drainage boreholes, there is an urgent need for a multi-sealing device to meet the needs of coal mine gas drainage. Summary of the Invention

[0004] The purpose of this invention is to address the problem of short service life of underground boreholes in coal mines by providing a continuous, multi-stage sealing device and sealing method.

[0005] To solve the above problems, the present invention adopts the following technical solution:

[0006] A continuous multi-stage sealing device, characterized in that it includes a first bone-shaped sleeve, a second bone-shaped sleeve, and an air extraction pipe and a multi-zone grouting pipe fitted onto the first and second bone-shaped sleeves. The two ends of the multi-zone grouting pipe are respectively connected to a grouting device and a water pump via a first connecting pipe and a second connecting pipe. The first and second bone-shaped sleeves have identical structures, each consisting of two large hollow circular tubes connected to a long, thin circular tube. The two large circular tubes are located at both ends of the long, thin circular tube, and each has a large hole in the middle of its two end faces. An inner pipe, first inner pipe and second inner pipe, are respectively located on both sides of the large hole. A short vertical pipe is also provided in the middle of the inner pipe, communicating with the outer wall of the large circular tube. The air extraction pipe passes through the large hole and through the bone-shaped sleeve. The system consists of a first and a second bone-shaped sleeve, which are fastened to the air extraction pipe by screwing. The multi-zone grouting pipe is composed of an arc-shaped pipe connected to two long pipes. The two long pipes pass through the inner pipes one and two, respectively. One of the long pipes has three grout outlets (outlet 1, outlet 3, and outlet 2) spaced at equal intervals. The two long pipes have water outlets corresponding to the positions of the vertical short pipes. The two large round pipes are respectively wrapped by elastic bags one and two. The elastic bags have a fine mesh structure, are ring-shaped, and are divided into multiple grid areas inside. They have good water permeability and a certain degree of elasticity. Each grid area of ​​the elastic bag contains a sufficient amount of expansion capsules.

[0007] Furthermore, the inner diameter of the large hole and the slender round pipe is comparable to the outer diameter of the air extraction pipe, the inner diameter of the first inner pipe and the second inner pipe is comparable to the outer diameter of the long pipe of the multi-zone grouting pipe, and the outer diameter of the two large round pipes is smaller than the borehole diameter.

[0008] Furthermore, the arc-shaped tube is connected to the ends of two long tubes respectively through two connectors. The arc-shaped tube and the two long tubes are provided with external threads at their interfaces, and the two connectors are provided with reverse internal threads at both ends. The connection is achieved through thread matching. The diameter of the arc-shaped tube and the two long tubes is slightly smaller than the diameter of the connectors.

[0009] Furthermore, a wireless pressure sensor is provided on the upper outer wall of the elastic bag to monitor the pressure value on the elastic bag.

[0010] Furthermore, the first slurry outlet is located in the middle of the two large round tubes of the first bone-shaped sleeve, the second slurry outlet is located in the middle of the two large round tubes of the second bone-shaped sleeve, and the third slurry outlet is located in the middle of the two large round tubes adjacent to the first and second bone-shaped sleeves.

[0011] Furthermore, an electric control valve 1, an electric control valve 3, and an electric control valve 2 are respectively installed on the inner wall side of the multi-zone grouting pipe corresponding to the grout outlet. An electric control valve 4 is installed in each of the vertical short pipes. Under the control of the controller, the electric control valves can realize the connection or blockage between the grout outlet, the water outlet and the multi-zone grouting pipe.

[0012] Furthermore, the expandable capsule is a capsule-like granular material with a particle size larger than the mesh pores of the elastic bag, and the constituent materials have super water absorption properties and can expand rapidly after absorbing water.

[0013] The sealing method of the continuous multiple sealing device described above is characterized by comprising the following steps:

[0014] a. Place elastic cloth bag one and elastic cloth bag two onto the large round tubes of bone-shaped sleeve one and bone-shaped sleeve two;

[0015] b. Pass the air extraction pipe through the large hole, and screw the first and second bone-shaped sleeves onto the air extraction pipe. Pass the two long pipes of the multi-zone grouting pipe through the inner pipes of the first and second bone-shaped sleeves respectively, so that the water outlets on the long pipes are connected with the corresponding vertical short pipes. At the same time, make the grout outlets one and two grout outlets located in the middle of the two large round pipes of the first and second bone-shaped sleeves respectively. Connect the long pipes and the arc-shaped pipes by screwing them together with the connector.

[0016] c. Send the multi-zone grouting pipe, the first bone casing, the second bone casing, and the air extraction pipeline into the coal seam borehole. Connect the multi-zone grouting pipe to the first connecting pipeline and the second connecting pipeline respectively. Then connect the first connecting pipeline to the grouting device and the second connecting pipeline to the water pump.

[0017] d. By controlling the electronic valve four through the controller, the long pipe is connected to the elastic filter bag through the vertical short pipe. The water pump is started to inject water into the multi-zone grouting pipe at low pressure. The water flows through the vertical short pipe to the elastic filter bag. The expansion capsule comes into contact with the water flowing through the elastic filter bag and expands, causing the elastic filter bag to support the inner wall of the borehole. At this time, the expanded elastic filter bag not only seals the gap between the bone sleeve one, bone sleeve two and the borehole, but also separates three independent closed spaces (sealing zone one, sealing zone two and sealing zone three).

[0018] e. When the wireless pressure sensor on the outside of the elastic bag detects a significant decrease in the rate of pressure change, it indicates that the elastic bag is close to saturation in terms of water absorption. Close the electric control valve and the water pressurizer, start the grouting machine, and use air pressure to press the remaining water in the multi-zone grouting pipe back to the water pressurizer.

[0019] f. The controller regulates the first electronically controlled valve to open only the first grout outlet, blocking the connection of the multi-zone grouting pipes;

[0020] g. Prepare the sealing grout, then start the grouting machine to send the sealing grout into the sealing zone 1 through the connecting pipe 1, the multi-zone grouting pipe and the grout outlet 1. The closed space formed by the elastic bag and the bone-like sleeve helps to achieve high-pressure grouting and sealing of the sealing grout, and improves the sealing performance of the borehole.

[0021] h. The controller regulates the electric control valves 1, 2 and 3 to close the grout outlets 1, 2 and 3, open the multi-zone grouting pipe, and start the pressure tank to push the residual sealing grout in the multi-zone grouting pipe back into the grouter, so as to empty and reuse the multi-zone grouting pipe.

[0022] i. After the sealing grout has solidified, the sealing operation of sealing zone one is completed, followed by gas extraction operation;

[0023] j. Stop gas extraction operation when the gas concentration drops to 4%;

[0024] k. The controller regulates the second electric control valve to only connect the second grout outlet and the grout injector, starts the grout injector, and sends the sealing grout into the second sealing zone through the second grout outlet. The controller regulates the three electric control valves to close the three grout outlets, starts the water pressure device, clears the residual sealing grout in the multi-zone grouting pipe, and completes the sealing operation of the second sealing zone.

[0025] l. Conduct gas extraction operations;

[0026] m. Stop gas extraction operation when the gas concentration drops to 4%;

[0027] n. The controller regulates the three-way electric control valve to connect only the outlet three to the grouter, and starts the grouter to send the sealing grout into the sealing zone three through the outlet three, completing the sealing operation of the sealing zone three. At this time, the sealing operations of the first and second sealing zones form a more stable sealing space for the sealing of the third sealing zone. The third sealing grout can not only seal the third sealing zone under greater pressure, but also tightly seal the newly generated pores and cracks in the coal wall of the first and second sealing zones, forming a large, dense space encompassing the first, second and third sealing zones, which can significantly improve the borehole sealing performance and extend the service life of the borehole.

[0028] o. Gas extraction operations were then carried out, thereby completing multiple sealing operations.

[0029] Furthermore, the low pressure is preferably 1-2 MPa, which can control the flow rate of water into the elastic filter bag and avoid the high flow rate caused by high water pressure, which would cause excess water to enter the borehole.

[0030] Beneficial effects

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] 1. The elastic cloth bag is wrapped around the hollow large round tube of the bone-shaped sleeve, which can effectively solve the problem of gaps left when the round tube directly contacts the uneven borehole wall, thus providing conditions for high-pressure slurry sealing of the borehole.

[0033] II. This device uses two bone-shaped sleeves screwed and fixed to the gas extraction pipeline, dividing it into three sealing zones: sealing zone one, sealing zone three, and sealing zone two. By sequentially filling sealing zone one and performing gas extraction, filling sealing zone two and gas extraction and filling sealing zone three, this operation method not only achieves multiple sealing operations and extends the service life of the borehole, but also ensures that sealing zone three is located in the middle of the filled sealing zones one and two. The third sealing slurry can not only seal sealing zone three under greater pressure, but also densely seal newly generated pores and cracks in the coal wall of sealing zones one and two, so that the sealing area forms a large, dense space encompassing sealing zones one, two and three, which can significantly improve the borehole sealing performance and extend the service life of the borehole.

[0034] Third, this device, by setting up a grouting device, multi-zone grouting pipes, electrically controlled valves, grout outlets, and water pressurizers, can force the sealing grout remaining in the multi-zone grouting pipes back into the grouting device after the sealing operation of the previous sealing zone is completed, thus achieving the effect of emptying and reusing the multi-zone grouting pipes; by setting up multiple bone-shaped sleeves and corresponding electrically controlled valves and grout outlets, multiple sealing operations can be carried out as required, which provides conditions for the extraction operation of long-distance high-gas working faces. Attached Figure Description

[0035] Figure 1This is a schematic diagram of the structure of the device of the present invention.

[0036] Figure 2 This is a schematic diagram of the structure of the multi-zone grouting pipe of the device of the present invention.

[0037] Figure 3 This is a schematic diagram of the structure of the bone-like sleeve and elastic cloth bag of the device of the present invention before and after immersion in water and expansion.

[0038] Figure 4 This is a schematic diagram of the internal structure of the bone-like sleeve of the device of the present invention.

[0039] Figure 5 This is a schematic diagram of the elastic cloth bag and its partitioned structure of the device of the present invention.

[0040] Figure 6 This is a schematic diagram of the threaded connection structure of the long tube, connector, and arc-shaped tube of the device of the present invention.

[0041] In the diagram: 1. Coal seam, 2. Borehole, 3. Air extraction pipeline, 4-1. Skeleton casing one, 4-2. Skeleton casing two, 5. Multi-zone grouting pipe, 6-1. Connecting pipeline one, 6-2. Connecting pipeline two, 7-1. Grouting device, 7-2. Water pump, 8. Controller, 9-1. Grout outlet one, 9-2. Grout outlet two, 9-3. Grout outlet three, 9-4. Water outlet, 10-1. Electrically controlled valve one, 10 -2. Electrically controlled valve 2, 10-3. Electrically controlled valve 3, 10-4. Electrically controlled valve 4, 11-1. Elastic cloth strip 1, 11-2. Elastic cloth strip 2, 12-1. Sealing area 1, 12-2. Sealing area 2, 12-3. Sealing area 3, 13-1. Inner pipe 1, 13-2. Inner pipe 2, 13-3. Vertical short pipe, 14. Connector, 14-1. External thread, 14-2. Internal thread. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0044] Example 1

[0045] like Figure 1-6As shown, a continuous multi-stage sealing device includes a bone-shaped sleeve 4-1, a bone-shaped sleeve 4-2, an air extraction pipe 3 and a multi-zone grouting pipe 5 fitted onto the bone-shaped sleeve 1 and the bone-shaped sleeve 2, respectively. The two ends of the multi-zone grouting pipe 5 are connected to a grouting device 7-1 and a water pump 7-2 via connecting pipe 1 6-1 and connecting pipe 2 6-2, respectively. The bone-shaped sleeve 4-1 and the bone-shaped sleeve 4-2 have identical structures, each consisting of two hollow large round tubes connected to a long, thin round tube. The two large round tubes are located at both ends of the long, thin round tube, and each end face has a large hole in the middle. Inner pipes 1 13-1 and 2 13-2 are respectively located on both sides of the large hole. A vertical short pipe 13-3 is also provided in the middle of the inner pipes, communicating with the outer wall of the large round tubes. The air extraction pipe 3 passes through the large hole and the bone-shaped sleeve 4-1. The first bone-shaped sleeve 4-1 and the second bone-shaped sleeve 4-2 are fastened to the air extraction pipe 3 by screwing. The multi-zone grouting pipe 5 is composed of an arc-shaped pipe connected to two long pipes. The two long pipes pass through the inner pipe 13-1 and the inner pipe 23-2 respectively. One of the long pipes is provided with grout outlet 19-1, grout outlet 39-3 and grout outlet 29-2 at equal intervals. The two long pipes are respectively provided with water outlet 9-4 at the position corresponding to the vertical short pipe 13-3. The two large round pipes are respectively wrapped by elastic cloth bag 11-1 and elastic cloth bag 21-2. The elastic cloth bag has a fine mesh structure, is a ring bag, and is divided into multiple grid areas inside. It has good water permeability and a certain elasticity. Each grid area of ​​the elastic cloth bag is filled with a sufficient amount of expansion capsules.

[0046] Furthermore, the inner diameter of the large hole and the slender round pipe is equivalent to the outer diameter of the air extraction pipe 3, and the inner diameter of the inner pipe 13-1 and the inner pipe 213-2 is equivalent to the outer diameter of the long pipe of the multi-zone grouting pipe 5. The outer diameter of the two large round pipes is smaller than the borehole diameter.

[0047] Furthermore, the arc-shaped tube is connected to the ends of the two long tubes respectively through two connectors 14. The arc-shaped tube and the two long tubes are provided with external threads 14-1 at their interfaces, and the two connectors 14 are provided with reverse internal threads 14-2 at both ends. The connection is achieved through thread matching. The diameter of the arc-shaped tube and the two long tubes is slightly smaller than the diameter of the connectors 14.

[0048] Furthermore, a wireless pressure sensor is provided on the upper outer wall of the elastic bag to monitor the pressure value on the elastic bag.

[0049] Furthermore, the first slurry outlet 9-1 is located in the middle of the two large round tubes of the first bone-shaped sleeve 4-1, the second slurry outlet 9-2 is located in the middle of the two large round tubes of the second bone-shaped sleeve 4-2, and the third slurry outlet 9-3 is located in the middle of the two large round tubes adjacent to the first bone-shaped sleeve 4-1 and the second bone-shaped sleeve 4-2.

[0050] Furthermore, on the inner wall side of the multi-zone grouting pipe 5, corresponding to the grout outlet, there are electrically controlled valves 10-1, 10-3, and 10-2, respectively. Each of the vertical short pipes 13-3 is equipped with an electrically controlled valve 4 10-4. Under the control of the controller, the electrically controlled valves can realize the connection or blockage between the grout outlet, the water outlet and the multi-zone grouting pipe.

[0051] Furthermore, the expandable capsule is a capsule-like granular material with a particle size larger than the mesh pores of the elastic bag, and the constituent materials have super water absorption properties and can expand rapidly after absorbing water.

[0052] Example 2

[0053] The sealing method of the continuous multi-stage sealing device described above includes the following steps:

[0054] a. Place the elastic cloth bag 11-1 and the elastic cloth bag 21-2 onto the large round tubes of the bone sleeve 14-1 and the bone sleeve 24-2;

[0055] b. Pass the air extraction pipe 3 through the large hole, and tighten the bone-shaped sleeve 4-1 and bone-shaped sleeve 4-2 onto the air extraction pipe 3. Pass the two long pipes of the multi-zone grouting pipe 5 through the inner pipes 13-1 and 13-2 on the bone-shaped sleeve 1 and bone-shaped sleeve 2 respectively, so that the water outlet 9-4 on the long pipe is connected to the corresponding vertical short pipe 13-3 one by one. At the same time, the grout outlet 9-1 and grout outlet 9-2 are located in the middle of the two large round pipes of the bone-shaped sleeve 1 and bone-shaped sleeve 2 respectively. Connect the long pipe and the arc-shaped pipe through the threaded screw of the connector 14.

[0056] c. Send the multi-zone grouting pipe 5, the first bone casing 4-1, the second bone casing 4-2 and the air extraction pipe 3 into the borehole 2 of the coal seam 1. Connect the multi-zone grouting pipe 5 to the first connecting pipe 6-1 and the second connecting pipe 6-2 respectively. Then connect the first connecting pipe 6-1 to the grouting device 7-1 and connect the second connecting pipe 6-2 to the water pump 7-2.

[0057] d. By controlling the electronic control valve 10-4 through the controller, the long pipe is connected to the elastic bag through the vertical short pipe 13-3. The water pump is started to inject water into the multi-zone grouting pipe 5 at low pressure. The water flows through the vertical short pipe 13-3 to the elastic bag. The expansion capsule comes into contact with the water flowing through the elastic cloth and expands, causing the elastic bag to support the inner wall of the borehole. At this time, the expanded elastic bag not only seals the gap between the bone sleeve 1, bone sleeve 2 and the borehole, but also separates three independent closed spaces (sealing zone 1 12-1, sealing zone 2 12-2 and sealing zone 3 12-3).

[0058] e. When the wireless pressure sensor on the outside of the elastic bag detects a significant decrease in the rate of pressure change, it indicates that the elastic bag is close to saturation in terms of water absorption. Close the electric control valve 10-4 and the water press 7-2, start the grouting device 7-1, and use air pressure to press the remaining water in the multi-zone grouting pipe back to the water press.

[0059] f. The controller adjusts the electronic control valve 10-1 to open only the grout outlet 9-1, blocking the connection of the multi-zone grouting pipes;

[0060] g. Prepare the sealing grout, and then start the grouting device 7-1 to send the sealing grout into the sealing zone 12-1 through the connecting pipe 6-1, the multi-zone grouting pipe 5 and the grout outlet 9-1. The closed space formed by the elastic bag and the bone-like sleeve helps to achieve high-pressure grouting and sealing of the sealing grout, and improves the sealing performance of the borehole.

[0061] h. The controller regulates the electric control valves 10-1, 10-2, and 10-3 to close the grout outlets 9-1, 9-2, and 9-3, thereby opening the multi-zone grouting pipe 5 and starting the pressure tank to push the residual sealing grout in the multi-zone grouting pipe back into the grouter, achieving the purpose of emptying and reusing the multi-zone grouting pipe;

[0062] i. After the sealing grout has solidified, complete the sealing operation of sealing zone 12-1, and then carry out gas extraction operation;

[0063] j. Stop gas extraction operation when the gas concentration drops to 4%;

[0064] k. The controller regulates the second electric control valve 10-2 to only open the grout outlet 9-2 and the grout injector 7-1. The grout injector 7-1 is started to send the sealing grout through the grout outlet 9-2 into the sealing zone 12-2. The controller regulates the three electric control valves to close the three grout outlets. The water pressure device is started to clear the residual sealing grout in the multi-zone grouting pipe and complete the sealing operation of the sealing zone 12-2.

[0065] l. Conduct gas extraction operations;

[0066] m. Stop gas extraction operation when the gas concentration drops to 4%;

[0067] n. The controller regulates the electric control valve 10-3 to connect only the grout outlet 9-3 and the grout injector 7-1. The grout injector 7-1 is started, and the sealing grout is sent into the sealing zone 12-3 through the grout outlet 9-3, completing the sealing operation of the sealing zone 12-3. At this time, the sealing operations of the sealing zones 1 and 2 form a more stable sealing space for the sealing zone 3. The third sealing grout can not only seal the sealing zone 3 under greater pressure, but also densely seal the newly generated pores and cracks in the coal wall of the sealing zones 1 and 2, forming a large, dense space encompassing the sealing zones 1, 2 and 3, which can significantly improve the borehole sealing performance and extend the service life of the borehole.

[0068] o. Gas extraction operations were then carried out, thereby completing multiple sealing operations.

[0069] Furthermore, the low pressure is preferably 1-2 MPa, which can control the flow rate of water into the elastic filter bag and avoid the high flow rate caused by high water pressure, which would cause excess water to enter the borehole.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any equivalent structures or equivalent transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A sealing method for a continuous multi-stage sealing device, the sealing device comprising a first bone-shaped sleeve, a second bone-shaped sleeve, and an air extraction pipe and a multi-zone grouting pipe sleeved on the first and second bone-shaped sleeves, the two ends of the multi-zone grouting pipe being connected to a grouting device and a water pump respectively via a first connecting pipe and a second connecting pipe; the first and second bone-shaped sleeves have the same structure, each consisting of two hollow large circular tubes connected to a long thin circular tube, the two large circular tubes being located at both ends of the long thin circular tube, and the middle of the two end faces of the large circular tubes being... A large opening is provided, with inner pipe circuit one and inner pipe circuit two on both sides of the large opening. A short vertical pipe is also provided in the middle of inner pipe circuit one and inner pipe circuit two, communicating with the outer wall of the large circular pipe. The air extraction pipe passes through the large opening and through bone-shaped sleeve one and bone-shaped sleeve two, and is secured to the air extraction pipe by threading. The multi-zone grouting pipe consists of an arc-shaped pipe connected to two long pipes. The two long pipes pass through inner pipe circuit one and inner pipe circuit two respectively, and are connected to the arc-shaped pipe at their ends. A long pipe has three grout outlets (outlet 1, outlet 3, and outlet 2) spaced at equal intervals, and two water outlets are respectively located on the two long pipes at positions corresponding to the vertical short pipes. The two large circular pipes are respectively wrapped by elastic bags 1 and 2. The elastic bags 1 and 2 have a fine mesh structure, are ring-shaped, and are internally divided into multiple grid zones, possessing good permeability and a certain degree of elasticity. Sufficient expansion capsules are placed in each grid zone of both elastic bags 1 and 2. Multi-zone grouting pipe. On the inner wall corresponding to grout outlet one, grout outlet three, and grout outlet two, there are electrically controlled valves one, three, and two, respectively. Each of the vertical short pipes is equipped with an electrically controlled valve four. Under the control of the controller, electrically controlled valve one can achieve connection or blockage between grout outlet one and the multi-zone grouting pipe; electrically controlled valve two can achieve connection or blockage between grout outlet two and the multi-zone grouting pipe; electrically controlled valve three can achieve connection or blockage between grout outlet three and the multi-zone grouting pipe; and electrically controlled valve four can achieve connection or blockage between the water outlet and the multi-zone grouting pipe. Its characteristic is that… Includes the following steps: a. Place the elastic bag on the large round tube of the first bone-shaped sleeve, and place the second elastic bag on the large round tube of the second bone-shaped sleeve; b. Pass the air extraction pipe through the large hole, and screw the first and second bone-shaped sleeves onto the air extraction pipe. Pass the two long pipes of the multi-zone grouting pipe through the inner pipes of the first and second bone-shaped sleeves respectively, so that the water outlets on the long pipes are connected with the corresponding vertical short pipes. At the same time, make the grout outlets one and two grout outlets located in the middle of the two large round pipes of the first and second bone-shaped sleeves respectively. Connect the long pipes and the arc-shaped pipes by screwing them together with the connector. c. Send the multi-zone grouting pipe, the first bone casing, the second bone casing, and the air extraction pipeline into the coal seam borehole. Connect the multi-zone grouting pipe to the first connecting pipeline and the second connecting pipeline respectively. Then connect the first connecting pipeline to the grouting device and the second connecting pipeline to the water pump. d. By controlling the electronic valve four through the controller, the long pipe is connected to the elastic filter bag one and elastic filter bag two through the vertical short pipe. The water pump is started to inject water into the multi-zone grouting pipe at low pressure. The water flows through the vertical short pipe to the elastic filter bag one and elastic filter bag two. The expansion capsule comes into contact with the water flowing through the elastic filter bag one and elastic filter bag two and expands, causing the elastic filter bag one and elastic filter bag two to push against the inner wall of the borehole. At this time, the expanded elastic filter bag one and elastic filter bag two not only seal the gap between the bone sleeve one and bone sleeve two and the borehole, but also separate three independent closed spaces: sealing zone one, sealing zone two and sealing zone three. e. When the wireless pressure sensors installed on the outside of elastic bag 1 and elastic bag 2 detect a significant decrease in the rate of pressure change, it indicates that elastic bag 1 and elastic bag 2 are close to saturation in terms of water absorption. Close the electric control valve 4 and the water press, start the grouting machine, and use air pressure to press the remaining water in the multi-zone grouting pipe back to the water press. f. The controller regulates the first electronically controlled valve to open only the first grout outlet, blocking the connection of the multi-zone grouting pipes; g. Prepare the sealing grout, then start the grouting machine to send the sealing grout into the sealing zone 1 through the connecting pipe 1, the multi-zone grouting pipe and the grout outlet 1. The closed space formed by the elastic bag 1, the elastic bag 2 and the bone-shaped sleeve helps to achieve high-pressure grouting and sealing of the sealing grout, and improves the sealing performance of the borehole. h. The controller regulates the electric control valves 1, 2 and 3 to close the grout outlets 1, 2 and 3, open the multi-zone grouting pipe, and start the pressure water tank to push the residual sealing grout in the multi-zone grouting pipe back into the grouter, so as to empty and reuse the multi-zone grouting pipe. i. After the sealing grout has solidified, complete the sealing operation of sealing zone one, and then carry out gas extraction operation; j. Stop gas extraction operation when the gas concentration drops to 4%; k. The controller regulates the second electric valve to only open the grout outlet 2 and the grout injector, starts the grout injector, and sends the sealing grout into the sealing zone 2 through the grout outlet 2. The controller regulates the first, second, and third electric valves to close the three grout outlets, starts the water pressure device, clears the residual sealing grout in the multi-zone grouting pipe, and completes the sealing operation of the sealing zone 2. l. Conduct gas extraction operations; m. Stop gas extraction operation when the gas concentration drops to 4%; n. The controller regulates the three-way electric control valve to connect only the outlet three to the grouter. The grouter is then activated, and the sealing grout is delivered into the sealing zone three through the outlet three, completing the sealing operation of the sealing zone three. At this time, the sealing operations of the first and second sealing zones form a more stable sealing space for the sealing of the third sealing zone. The third sealing grout can not only seal the third sealing zone under greater pressure, but also tightly seal the newly generated pores and cracks in the coal wall of the first and second sealing zones, forming a large, dense space encompassing the first, second, and third sealing zones. This can significantly improve the borehole sealing performance and extend the service life of the borehole. o. Gas extraction was then carried out, which involved multiple sealing operations.

2. The sealing method of the continuous multiple sealing device according to claim 1, characterized in that, The low pressure is 1~2 MPa, which can control the flow of water into the first and second elastic filter bags, and avoid the high flow caused by high water pressure, which would cause excess water to enter the borehole.

3. The sealing method of the continuous multiple sealing device according to claim 1, characterized in that, The inner diameter of the large hole and the long slender round pipe is equivalent to the outer diameter of the air extraction pipe. The inner diameter of the first inner pipe and the second inner pipe is equivalent to the outer diameter of the long pipe of the multi-zone grouting pipe. The outer diameter of the two large round pipes is smaller than the borehole diameter.

4. The sealing method of the continuous multiple sealing device according to claim 1, characterized in that, The arc-shaped tube is connected to the ends of two long tubes respectively through two connectors. The arc-shaped tube and the two long tubes are provided with external threads at their interfaces, and the two connectors are provided with reverse internal threads at both ends. The connection is achieved by thread matching. The diameter of the arc-shaped tube and the two long tubes is slightly smaller than the diameter of the connectors.

5. The sealing method of the continuous multiple sealing device according to claim 1, characterized in that, The first slurry outlet is located in the middle of the two large round tubes of the first bone-shaped sleeve, the second slurry outlet is located in the middle of the two large round tubes of the second bone-shaped sleeve, and the third slurry outlet is located in the middle of the two large round tubes adjacent to the first and second bone-shaped sleeves.

6. The sealing method of the continuous multiple sealing device according to claim 1, characterized in that, The expandable capsule is a capsule-like granular material with a particle size larger than the mesh pores of elastic bag one and elastic bag two, and the constituent materials have super water absorption properties and can expand rapidly after absorbing water.

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