An integrated device and method for water-containing coal seam gas extraction and spraying sealing

Abstract

The present application belongs to the field of coal seam gas control and safety technology, and specifically discloses a water-containing coal seam gas extraction and spraying type sealing integrated device and method. The device is used to solve the problem of poor sealing of water-containing coal seam drilling. It is beneficial to the sealing of water-containing coal seam drilling. The device comprises a ring-shaped nozzle, a gas extraction pipe, a hole sealing cement transmission steel pipe, a water-absorbing resin transmission steel pipe, an inner polyurethane hole sealing material bag, an outer polyurethane hole sealing material bag, a hole sealing cement slurry storage tank, a water-absorbing resin slurry storage tank and a gas extraction system. The side surface of the ring-shaped nozzle is uniformly provided with a plurality of spray holes, and the ring-shaped nozzle is connected with a pressure sensor. The gas extraction pipe is connected with the gas extraction system, the hole sealing cement transmission steel pipe is connected with the hole sealing cement slurry storage tank, the water-absorbing resin transmission steel pipe is connected with the water-absorbing resin slurry storage tank, and the gas extraction pipe, the hole sealing cement transmission steel pipe and the water-absorbing resin transmission steel pipe all pass through the ring-shaped nozzle and are connected with the outer polyurethane hole sealing material bag and the inner polyurethane hole sealing material bag.

Description

Technical Field

[0001] This invention belongs to the field of coal seam gas control and safety technology, and particularly relates to an integrated device and method for gas extraction and spray sealing in water-bearing coal seams. Background Technology

[0002] The quality of borehole sealing directly affects the functionality of various boreholes. In my country, over two-thirds of mines have poor sealing performance in their gas drainage boreholes, with approximately 65% ​​of working faces having pre-drainage gas concentrations below 30%, failing to meet the requirements of the "Regulations for the Prevention and Control of Coal and Gas Outbursts." This phenomenon fully reflects the current poor sealing quality of gas drainage boreholes in my country.

[0003] Most existing borehole sealing technologies assume that the wellbore is water-free or has very low water content, neglecting the impact of water on the wellbore sealing effect. However, for the vast majority of borehole seals, the presence of water in the mine causes poor sealing, and in some coal seams with high water content, seal failure may even occur. Therefore, there is an urgent need to conduct research on sealing methods for water-bearing gas drainage boreholes to meet the needs of borehole sealing in water-bearing coal seams. Summary of the Invention

[0004] One objective of this invention is to provide an integrated device for gas extraction and spray sealing in water-bearing coal seams, effectively solving the problem of poor borehole sealing in water-bearing coal seams.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] An integrated device for gas extraction and spray sealing in water-bearing coal seams includes an annular nozzle, a gas extraction pipe, a sealing cement transmission steel pipe, a water-absorbing resin transmission steel pipe, an inner polyurethane sealing material bag, an outer polyurethane sealing material bag, a sealing cement slurry storage tank, a water-absorbing resin slurry storage tank, and a gas extraction system.

[0007] The annular nozzle has multiple spray holes evenly distributed on its side. The annular nozzle is connected to a pressure sensor for controlling the uniform movement and spraying of the annular nozzle within the borehole. The left end of the gas extraction pipe is connected to the gas extraction system. The left end of the sealing cement transmission steel pipe is connected to the sealing cement storage tank. The left end of the water-absorbing resin transmission steel pipe is connected to the water-absorbing resin storage tank. The right ends of the gas extraction pipe, the sealing cement transmission steel pipe, and the water-absorbing resin transmission steel pipe all pass through the annular nozzle and are connected to the outer and inner polyurethane sealing material bags located on the left and right sides of the annular nozzle. The right end of the gas extraction pipe extends beyond the inner polyurethane sealing material bag, and the portion of the gas extraction pipe exceeding the inner polyurethane sealing material bag has multiple gas extraction holes.

[0008] The absorbent resin transmission steel pipe located between the outer polyurethane sealing material bag and the absorbent resin storage tank is equipped with a first grouting pump, a first pressure gauge and a first valve from left to right. The sealing cement transmission steel pipe located between the outer polyurethane sealing material bag and the sealing cement storage tank is equipped with a second grouting pump, a second pressure gauge and a second valve from left to right.

[0009] Another objective of this invention is to provide a method for gas extraction and spray sealing of water-bearing coal seams, applied to the integrated device for gas extraction and spray sealing of water-bearing coal seams described in the above embodiments, comprising the following steps.

[0010] S1. Connect and fix the gas extraction pipe, the sealing cement transmission steel pipe and the water-absorbing resin transmission steel pipe to the annular nozzle, the inner polyurethane sealing material bag and the outer polyurethane sealing material bag.

[0011] S2. After mixing the materials in the inner and outer polyurethane sealing material bags evenly, insert the gas extraction pipe into the borehole.

[0012] S3. After the inner and outer polyurethane sealing material bags have reacted and cured, connect the sealing cement transmission steel pipe to the sealing cement storage tank, the second grouting pump, the second pressure gauge, and the second valve, and connect the water-absorbing resin transmission steel pipe to the water-absorbing resin storage tank, the first grouting pump, the first pressure gauge, and the first valve.

[0013] S4. First, open the first grouting pump and the first valve, and use the pressure sensor to control the annular nozzle to uniformly spray water-absorbing resin material onto the inner wall of the borehole.

[0014] S5. After the water-absorbing resin material reacts with the water on the inner wall of the borehole to form a liquid-solid dual-phase adhesive gel, the first grouting pump and the first valve are closed, and the second grouting pump and the second valve are opened. Cement sealing material is then sprayed through an annular nozzle.

[0015] S6. After grouting is completed, let it stand for 48 hours. After the cement sealing material in the sealing section between the inner and outer polyurethane sealing material bags has cured, connect the gas extraction pipe to the gas extraction system to perform gas extraction, thus completing the integrated process of gas extraction and spray sealing of water-bearing coal seams.

[0016] Furthermore, the absorbent resin material is sodium polyacrylate.

[0017] Furthermore, in step S3, the reaction curing time of the inner polyurethane sealing material bag and the outer polyurethane sealing material bag is 10 to 30 minutes.

[0018] Furthermore, the distance between the inner polyurethane sealing material bag and the right end of the gas extraction pipe is 0.5m, and the distance between the outer polyurethane sealing material bag and the right end of the gas extraction pipe is 10m.

[0019] Furthermore, the length of the drill hole is 12-15m and the diameter is 100-120mm.

[0020] Compared with the prior art, the beneficial technical effects of the present invention are:

[0021] This invention utilizes the abundant water in the water-bearing coal seam to cause the water-absorbing resin material to continuously absorb water and expand, filling the voids in the gas drainage borehole caused by the shrinkage of cement mortar. Furthermore, the water-absorbing resin material, upon contact with water, forms a liquid-solid two-phase adhesive gel that penetrates into the coal seam fissures, creating an effective seal. Simultaneously, it effectively seals cracks near the borehole, significantly increasing the gas drainage density and improving the gas drainage effect, thus achieving the goals of borehole sealing, increasing coal seam strength, and enhancing drainage concentration. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention.

[0023] Figure 2 yes Figure 1 A schematic diagram of the connection structure of the central annular nozzle.

[0024] Figure 3 This is a cross-sectional view of the borehole used in Embodiment 2 of the present invention to complete the integrated process of gas extraction and spray sealing of water-bearing coal seams. Detailed Implementation

[0025] Example 1

[0026] An integrated device for gas extraction and spray sealing in water-bearing coal seams, such as Figure 1 and Figure 2 As shown, it includes an annular nozzle 1, a gas extraction pipe 2, a sealing cement transmission steel pipe 3, a water-absorbing resin transmission steel pipe 4, an inner polyurethane sealing material bag 5, an outer polyurethane sealing material bag 6, a sealing cement slurry storage tank 7, a water-absorbing resin slurry storage tank 8, and a gas extraction system 9.

[0027] The annular nozzle 1 has multiple spray holes 10 evenly distributed on its side. A pressure sensor 12 is connected to the annular nozzle 1 to control its uniform movement and spraying within the borehole 11. The pressure sensor 12 is arranged around the annular nozzle 1. The left end of the gas extraction pipe 2 is connected to the gas extraction system 9. The left end of the sealing cement transmission steel pipe 3 is connected to the sealing cement storage tank 7. The left end of the water-absorbing resin transmission steel pipe 4 is connected to the water-absorbing resin storage tank 8.

[0028] The right ends of the gas extraction pipe 2, the sealing cement transmission steel pipe 3, and the water-absorbing resin transmission steel pipe 4 all pass through the annular nozzle 1 and are connected to the outer polyurethane sealing material bags 6 and inner polyurethane sealing material bags 5 located on the left and right sides of the annular nozzle 1. The right end of the gas extraction pipe 2 extends approximately 0.5m beyond the inner polyurethane sealing material bag 5, and multiple gas extraction holes 13 are provided on the portion of the gas extraction pipe 2 that exceeds the inner polyurethane sealing material bag 5. The right ends of the sealing cement transmission steel pipe 3 and the water-absorbing resin transmission steel pipe 4 do not extend beyond the inner polyurethane sealing material bag 5. In this embodiment, a pressure sensor 12 is connected to the annular nozzle 1 and fitted onto the gas extraction pipe 2. The sealing cement transmission steel pipe 3 and the water-absorbing resin transmission steel pipe 4 both pass through the annular nozzle 1 and are fixed to the outer polyurethane sealing material bags 6 and inner polyurethane sealing material bags 5 at both ends.

[0029] The absorbent resin transmission steel pipe 4 located between the outer polyurethane sealing material bag 6 and the absorbent resin storage tank 8 is provided with a first grouting pump 14, a first pressure gauge 15 and a first valve 16 from left to right. The absorbent resin material A in the absorbent resin storage tank 8 is pressurized and transported through the first grouting pump 14 and the annular nozzle 1.

[0030] A second grouting pump 17, a second pressure gauge 18, and a second valve 19 are sequentially installed from left to right on the sealing cement transmission steel pipe 3 located between the outer polyurethane sealing material bag 6 and the sealing cement storage tank 7. The cement sealing material B in the sealing cement storage tank 7 is pressurized and transported through the second grouting pump 17 and the annular nozzle 1.

[0031] In this embodiment, the annular nozzle 1 has a diameter of 40 mm and a width of 50 mm; the spray hole 10 has a diameter of 1 mm; the sealing cement transmission steel pipe 3 and the water-absorbing resin transmission steel pipe 4 both have a diameter of 10 mm; the outer polyurethane sealing material bag 6 and the inner polyurethane sealing material bag 5 both have a diameter of 100-120 mm and a width of 50 cm.

[0032] Example 2

[0033] A method for gas extraction and spray sealing in water-bearing coal seams, applied to the integrated device for gas extraction and spray sealing in water-bearing coal seams described in Example 1, includes the following steps:

[0034] (1) A conventional drilling method was used to drill a hole vertically into the water-bearing coal seam 20, and a hole 11 with a length of 12-15m and a diameter of 100-120mm was obtained.

[0035] (2) Insert the three pipes, namely the gas extraction pipe 2, the sealing cement transmission steel pipe 3 and the water-absorbing resin transmission steel pipe 4, into the annular nozzle 1 respectively. The right end of the gas extraction pipe 2 extends about 75cm beyond the right end of the sealing cement transmission steel pipe 3 and the right end of the water-absorbing resin transmission steel pipe 4.

[0036] (3) Fix the inner polyurethane sealing material bag 5 and the outer polyurethane sealing material bag 6 at a distance of 0.5m and 10m from the right end of the gas extraction pipe 2, respectively. At the same time, fix the sealing cement transmission steel pipe 3 and the water-absorbing resin transmission steel pipe 4 on the inner polyurethane sealing material bag 5 and the outer polyurethane sealing material bag 6.

[0037] (4) After mixing the materials in the inner polyurethane sealing material bag 5 and the outer polyurethane sealing material bag 6 evenly, insert the gas extraction pipe 2 into the borehole 11.

[0038] (5) After waiting 10 to 30 minutes for the inner polyurethane sealing material bag 5 and the outer polyurethane sealing material bag 6 to react and cure, connect the sealing cement transmission steel pipe 3 to the sealing cement storage tank 7, the second grouting pump 17, the second pressure gauge 18 and the second valve 19, and connect the water-absorbing resin transmission steel pipe 4 to the water-absorbing resin storage tank 8, the first grouting pump 14, the first pressure gauge 15 and the first valve 16.

[0039] (6) First, open the first grouting pump 14 and the first valve 16, and use the pressure sensor 12 to control the annular nozzle 1 to uniformly spray the water-absorbing resin material A onto the inner wall of the drill hole 11. In this embodiment, the water-absorbing resin material A is sodium polyacrylate.

[0040] (7) After the water-absorbing resin material A reacts with the water on the inner wall of the borehole 11 to form a liquid-solid dual-phase adhesive, the first grouting pump 14 and the first valve 16 are closed, the second grouting pump 17 and the second valve 19 are opened, and the cement sealing material B is sprayed through the annular nozzle 1.

[0041] (8) After grouting is completed, allow the mixture to stand for 48 hours. Once the cement sealing material B in the sealing section between the inner polyurethane sealing material bag 5 and the outer polyurethane sealing material bag 6 has cured, connect the gas extraction pipe 2 to the gas extraction system 9 for gas extraction. Figure 3 As shown, the integrated process of gas extraction and spray sealing of water-bearing coal seams is completed.

[0042] This invention is simple to operate, highly effective, and time-saving. By utilizing the abundant water in the aquifer, the water-absorbing resin material continuously absorbs water and expands, filling the voids in the gas drainage boreholes caused by the shrinkage of cement mortar. Furthermore, the water-absorbing resin material, upon contact with water, forms a liquid-solid two-phase adhesive gel that penetrates into the coal seam fissures, creating an effective seal. Simultaneously, this invention effectively seals cracks near the borehole, significantly increasing the gas drainage density and improving the gas drainage effect, achieving the goals of borehole sealing and increasing coal strength and drainage concentration. This contributes to maximizing the safety and economic benefits of the mining area.

[0043] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for gas extraction and spray sealing in water-bearing coal seams, characterized in that, An integrated device for gas extraction and spray sealing in water-bearing coal seams is provided. The integrated device includes an annular nozzle, a gas extraction pipe, a sealing cement transmission steel pipe, a water-absorbing resin transmission steel pipe, an inner polyurethane sealing material bag, an outer polyurethane sealing material bag, a sealing cement slurry storage tank, a water-absorbing resin storage tank, and a gas extraction system. The annular nozzle has multiple spray holes evenly distributed on its side. The annular nozzle is connected to a pressure sensor for controlling the uniform movement and spraying of the annular nozzle within the borehole. The left end of the gas extraction pipe is connected to the gas extraction system. The left end of the sealing cement transmission steel pipe is connected to the sealing cement storage tank. The left end of the water-absorbing resin transmission steel pipe is connected to the water-absorbing resin storage tank. The right ends of the gas extraction pipe, the sealing cement transmission steel pipe, and the water-absorbing resin transmission steel pipe all pass through the annular nozzle and are connected to the outer and inner polyurethane sealing material bags located on the left and right sides of the annular nozzle. The right end of the gas extraction pipe extends beyond the inner polyurethane sealing material bag, and the portion of the gas extraction pipe exceeding the inner polyurethane sealing material bag has multiple gas extraction holes. The absorbent resin transmission steel pipe located between the outer polyurethane sealing material bag and the absorbent resin storage tank is equipped with a first grouting pump, a first pressure gauge and a first valve from left to right. The sealing cement transmission steel pipe located between the outer polyurethane sealing material bag and the sealing cement storage tank is equipped with a second grouting pump, a second pressure gauge and a second valve from left to right. Includes the following steps: S1. Connect and fix the gas extraction pipe, the sealing cement transmission steel pipe and the water-absorbing resin transmission steel pipe to the annular nozzle, the inner polyurethane sealing material bag and the outer polyurethane sealing material bag. S2. After mixing the materials in the inner and outer polyurethane sealing material bags evenly, insert the gas extraction pipe into the borehole. S3. After the inner polyurethane sealing material bag and the outer polyurethane sealing material bag have reacted and cured, connect the sealing cement transmission steel pipe to the sealing cement storage tank, the second grouting pump, the second pressure gauge and the second valve, and connect the water-absorbing resin transmission steel pipe to the water-absorbing resin storage tank, the first grouting pump, the first pressure gauge and the first valve. S4. First, open the first grouting pump and the first valve, and use the pressure sensor to control the annular nozzle to uniformly spray water-absorbing resin material onto the inner wall of the borehole. S5. After the water-absorbing resin material reacts with the water on the inner wall of the borehole to form a liquid-solid dual-phase adhesive gel, the first grouting pump and the first valve are closed, the second grouting pump and the second valve are opened, and the cement sealing material is sprayed through the annular nozzle. S6. After grouting is completed, let it stand for 48 hours. After the cement sealing material in the sealing section between the inner and outer polyurethane sealing material bags has cured, connect the gas extraction pipe to the gas extraction system to perform gas extraction, thus completing the integrated process of gas extraction and spray sealing of water-bearing coal seams.

2. The method for gas extraction and spray sealing of water-bearing coal seams according to claim 1, characterized in that, The absorbent resin material is sodium polyacrylate.

3. The method for gas extraction and spray sealing of water-bearing coal seams according to claim 2, characterized in that, In step S3, the reaction curing time of the inner polyurethane sealing material bag and the outer polyurethane sealing material bag is 10 to 30 minutes.

4. The method for gas extraction and spray sealing of water-bearing coal seams according to claim 3, characterized in that, The distance between the inner polyurethane sealing material bag and the right end of the gas extraction pipe is 0.5m, and the distance between the outer polyurethane sealing material bag and the right end of the gas extraction pipe is 10m.

5. The method for gas extraction and spray sealing of water-bearing coal seams according to claim 4, characterized in that, The length of the borehole is 12-15m and the diameter is 100-120mm.

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