Coal seam gas extraction drill hole three-plugging two-injection plugging device based on microbial mineralization

Abstract

The utility model discloses a coal seam gas extraction drill hole three-plugging two-injection plugging device based on microbial mineralization, which is characterized in that a three-plugging two-injection hole packer is mounted on a gas extraction pipe, and the gas extraction pipe is positioned in a drill hole in a pre-extraction coal seam; the three bags are sequentially arranged in a drill hole at intervals, a coal fracture development area near the drill hole is divided into a biological grouting section and a biological cement grouting section, the inner ends of the biological grouting pipe and the biological slurry return pipe are located in the biological grouting section, and the biological cement grouting pipe and the biological cement slurry return pipe are located in the biological cement grouting section; the microbial fermentation tank is connected with a mining stirring grouting pump through a biological liquid conveying pipe and a flow control valve, and the biological liquid is conveyed into the mining stirring grouting pump; the mining stirring grouting pump is connected with the biological grouting pipe and the biological cement grouting pipe through the one-to-two valve. Biological liquid can be injected for multiple times for repairing along with coal fracture development, a gas leakage channel of a coal body near a gas extraction drill hole is effectively sealed, and the gas extraction effect is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to coal seam gas extraction drilling hole sealing technical field especially relates to a kind of coal seam gas extraction drilling hole three plugging two injection plugging devices based on microorganism mineralization. BACKGROUND

[0002] Gas extraction is the main technical means for preventing and treating coal mine gas disasters, and the drilling gas extraction volume accounts for more than 90% of the total extraction volume. Due to the limitation of the current sealing and grouting materials and technology, the coal body fissure near the extraction drilling hole in most of the low-permeability coal seams in China is highly developed, and the gas leakage is serious during the extraction process, resulting in the failure of the drilling hole sealing. At the same time, as a clean and efficient energy source, the extraction effect and concentration of coal seam gas will determine whether it can be used again. Therefore, the efficient plugging of the coal body fissure around the drilling hole is of great significance to improve the gas extraction efficiency, ensure the safety of underground operation and achieve the "double carbon" goal of China.

[0003] The traditional "two plugging and one injection" pressure grouting method realizes the grouting of the drilling hole wall, and the slurry supports the drilling hole after solidification. Under the action of the expansion force, the slurry enters the drilling hole wall fissure to plug, reduces the gas leakage channel and improves the sealing performance of the sealing section. However, due to the strength limitation of the bag or polyurethane, the grouting pressure should not be too high, and the cement slurry cannot be pumped into the fissure in the deep area around the drilling hole, which cannot achieve the purpose of strict plugging. The "two plugging and one injection" can provide effective sealing at the initial stage of extraction, but as the continuous extraction and the advance of the working face, the coal body is affected by mining, and new fissures are continuously developed and the old fissures are connected, resulting in the increase of the drilling hole gas leakage. Since the drilling hole is sealed by cement or polyurethane, the fissures developed during the extraction process cannot be repaired. Therefore, improving the plugging of the gas leakage channel in the deep surrounding rock of the drilling hole is the key to realizing long-term and efficient gas extraction and preventing and treating gas disasters.

[0004] As a biological mineralization method, microbially induced calcium carbonate precipitation (MICP) can plug and fill the pores of porous media and cement the material particle matrix. In recent years, it has been widely used in concrete crack repair and soil reinforcement, and has made certain research progress in the repair and reinforcement of primary and secondary cracks in coal body. Therefore, MICP can effectively reduce cement cracking, improve the sealing performance of the drilling hole and improve the sealing efficiency. Compared with traditional cement slurry, the biological liquid made of bacteria solution and nutrient solution can enter the fissure under smaller pressure, effectively inhibiting the fissure development near the orifice due to mining, drilling and extraction.

[0005] To achieve the above purpose, the utility model provides a coal seam gas extraction drilling hole three plugging two injection plugging device based on biological mineralization technology. UTILITY MODEL CONTENTS

[0006] The utility model discloses a coal seam gas extraction drilling three plugging two injection leak stoppage device based on biological mineralization technology to guarantee that coal seam gas extraction drilling realizes efficient leak stoppage within service life.

[0007] To realize the above-mentioned purpose, the utility model provides the following technical scheme:

[0008] The coal seam gas extraction drilling three plugging two injection leak stoppage device based on biological mineralization includes a microbial fermentation tank, a mining stirring grouting pump and a three plugging two injection hole sealing device.

[0009] The three plugging two injection hole sealing device includes a bag, a biological grouting pipe, a biological back grouting pipe, a biological cement grouting pipe and a biological cement back grouting pipe.

[0010] The microbial fermentation tank is provided with an air inlet pipe, a liquid outlet, an air outlet, a fermentation tank valve and a liquid inlet, and is internally provided with a biological liquid stirrer.

[0011] The microbial fermentation tank is connected with the mining stirring grouting pump through a biological liquid conveying pipe and a flow control valve to convey biological liquid into the mining stirring grouting pump.

[0012] The mining stirring grouting pump is internally provided with a mixing stirrer and is further connected with a grouting pump.

[0013] The biological grouting pipe and the biological cement grouting pipe are respectively provided with a biological grouting pipe valve and a biological cement grouting pipe valve.

[0014] The biological back grouting pipe is provided with a biological back grouting pipe valve, the biological cement back grouting pipe is provided with a biological cement back grouting pipe valve, and the biological cement grouting pipe is further provided with a blasting valve.

[0015] The biological cement grouting section is not less than 10m, and the biological grouting section is not less than 3m.

[0016] The interval between the centers of the three bags is 4m and 14m, and the outermost bag is 1m away from the outer end of the gas extraction pipe; the gas extraction pipe is sent into the borehole, 0.5m is reserved at the outer end of the borehole, the biological grouting pipe is 4m long, the biological cement grouting pipe is 19.5m long, the biological back grouting pipe is 5m long, and the biological cement back grouting pipe is 18m long.

[0017] The biological cement grouting pipe is connected with the three bags and the biological cement grouting section, and the biological cement back grouting pipe is connected with the biological cement grouting section 18. The biological grouting pipe and the biological back grouting pipe are connected with the biological grouting section. After the installation of the three-plugging and two-injection hole packer is completed, all the pipelines are reserved outward from the borehole by not less than 0.5m.

[0018] The mine stirring grouting pump is provided with a bunker, can perform liquid and material stirring operation, and can pump the slurry into the pipeline under pressure.

[0019] After the pre-extraction of the coal seam is completed, the three-plugging and two-injection hole packer is installed on the gas extraction pipe and sent into the hole.

[0020] The mine stirring grouting pump is connected with the three-plugging and two-injection hole packer, the biological cement material is prepared by using the mixing stirrer in the pump, and after the mixing is sufficient, it is pumped to fill the bag as a plug, seal the inside of the borehole to form two grouting sections, when the pressure reaches 1.5MPa, the burst valve on the biological cement grouting pipe is opened to perform operation on the biological cement grouting section, and after the back grouting of the biological cement back grouting pipe, the pipe is closed to maintain pressure.

[0021] The flow valve is opened to transport the biological liquid to the mine stirring grouting pump, and then the biological liquid is pumped into the biological grouting section, when the grouting pressure reaches 0.5MPa, after the back grouting of the biological back grouting pipe, the pipe is closed to maintain pressure.

[0022] When the gas concentration is lower than 30%, the biological grouting pipe and the biological back grouting pipe are opened to ensure continuous and efficient plugging and prolong the service life of the borehole.

[0023] The use method of the three-plugging and two-injection plugging device for the coal seam gas extraction borehole based on microbial mineralization is as follows:

[0024] (1) After the pre-extraction of the coal seam is completed, the three-plugging and two-injection hole packer with three bags, biological grouting pipe, biological back grouting pipe, biological cement grouting pipe and biological cement back grouting pipe in the device is installed on the gas extraction pipe and sent into the hole, the outer end of the gas extraction pipe is reserved by 0.5m, the grouting pipe and the back grouting pipe are provided with valves, and the grouting pipe is connected with the grouting pump and the grouting pipe;

[0025] (2) The biological cement material is prepared in the grouting pump, injected into the cement grouting pipe, filled into the bag as a plug, sealed the inside of the borehole to form two grouting sections, when the pressure reaches 1.5MPa, the burst valve on the grouting pipe is opened to perform operation on the cement grouting section, and after the back grouting of the cement back grouting pipe, the pipe is closed to maintain pressure, and the inside support and sealing operation of the borehole is completed.

[0026] (3) Pump the biological liquid into the biological grouting section through the biological grouting pipe, and when the grouting pressure reaches 0.5 MPa, close the biological grouting pipe to maintain pressure;

[0027] (4) Connect the gas extraction pipe into the extraction pipe network system, complete the construction, and periodically monitor the gas extraction concentration subsequently;

[0028] (5) When the gas concentration is lower than 30%, open the biological grouting pipe and the back grouting pipe to repeat (3), so as to ensure continuous and efficient plugging and prolong the service life of the drilling hole.

[0029] The biological liquid is a concentrated mother liquor of Pseudomonas with denitrification function mixed and prepared with culture solution.

[0030] The Pseudomonas culture solution is 19.83 g / L C4H4Na2O4·6H2O, 2.49 g / L CaCl2, 2.15 g / L NaNO3 and 0.05 g / L MgSO4.

[0031] The beneficial effects of the utility model are:

[0032] The biological liquid with mineralization ability is combined with cement, the biological liquid can penetrate into the internal part of the coal body crack concentrated development area for mineralization precipitation plugging, effectively solves the problem that the traditional hole sealing material is difficult to penetrate into the internal part of the crack, and improves the plugging effect.

[0033] The biological cement has a self-repairing function, when the coal body crack is cracked again in the mining process, the biological cement can automatically repair, and ensure the continuous effectiveness of the plugging.

[0034] With the development of the coal body crack in the mining process, the biological liquid can be injected multiple times for repair, adapt to the dynamic change in the gas extraction process, and ensure the stability of the extraction effect.

[0035] The device has reasonable structure, can effectively seal the air leakage channel of the coal body near the drilling hole in the gas extraction process, thereby significantly improving the effect of gas extraction, and has good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a whole structure schematic view of the utility model;

[0037] In the figure: 1 - pre-extraction coal seam, 2 - coal body fracture development area near the borehole, 3 - borehole, 4 - gas extraction pipe, 5 - bag, 6 - biological grouting pipe, 7 - biological back grouting pipe, 8 - biological grouting pipe valve, 9 - biological back grouting pipe valve, 10 - biological cement grouting pipe, 11 - biological cement back grouting pipe, 12 - biological cement grouting pipe valve, 13 - biological cement back grouting pipe valve, 14 - biological liquid, 15 - biological cement slurry, 16 - blasting valve, 17 - biological grouting section, 18 - biological cement grouting section, 19 - grouting pump, 20 - one-to-two valve, 21 - mixing blender, 22 - mining mixing grouting pump, 23 - flow control valve, 24 - biological liquid conveying pipe, 25 - microbial fermentation tank, 26 - air inlet pipe, 27 - liquid outlet, 28 - gas outlet, 29 - biological liquid blender, 30 - fermentation tank valve, 31 - liquid inlet. DETAILED DESCRIPTION

[0038] According to the accompanying Figure 1 The specific working mode of the coal seam gas extraction borehole three-plugging and two-injection leak-stopping device based on the biological mineralization technology is illustrated.

[0039] The three-plugging and two-injection hole sealing device comprises a bag 5, a biological grouting pipe 6, a biological back grouting pipe 7, a biological cement grouting pipe 10 and a biological cement back grouting pipe 11; the three-plugging and two-injection hole sealing device is installed on the gas extraction pipe 4, and the gas extraction pipe 4 is located in the borehole 3 in the pre-extraction coal seam 1; three bags 5 are sequentially and spacedly arranged in the borehole 3, so as to divide the coal body fracture development area 2 near the borehole into a biological grouting section 17 and a biological cement grouting section 18; the outer ends of the biological grouting pipe 6, the biological back grouting pipe 7, the biological cement grouting pipe 10 and the biological cement back grouting pipe 11 are aligned with the gas extraction pipe 4; the inner ends of the biological grouting pipe 6 and the biological back grouting pipe 7 are located in the biological grouting section 17; and the biological cement grouting pipe 10 and the biological cement back grouting pipe 11 are located in the biological cement grouting section 18.

[0040] The microbial fermentation tank 25 is provided with an air inlet pipe 26, a liquid outlet 27, a gas outlet 28, a fermentation tank valve 30 and a liquid inlet 31, and is internally provided with a biological liquid blender 29.

[0041] The microbial fermentation tank 25 is connected to the mining mixing grouting pump 22 through the biological liquid conveying pipe 24 and the flow control valve 23, and the biological liquid 14 is conveyed into the mining mixing grouting pump 22.

[0042] The mining stirring grouting pump 22 is provided with a mixing stirrer 21, and is further connected with the grouting pump 19; the mining stirring grouting pump 22 is connected with the biological grouting pipe 6 and the biological cement grouting pipe 10 through a one-to-two valve 20, and the biological grouting pipe 6 and the biological cement grouting pipe 10 are respectively provided with a biological grouting pipe valve 8 and a biological cement grouting pipe valve 12;

[0043] The biological grouting pipe 7 is provided with a biological grouting pipe valve 9, the biological cement grouting pipe 11 is provided with a biological cement grouting pipe valve 13, and the biological cement grouting pipe 10 is further provided with a blasting valve 16; the blasting valve 16 is located in the biological cement grouting section 18.

[0044] Firstly, a drilling hole 3 with a depth of 24 m and a diameter of Φ120 mm is constructed in the pre-drained coal seam 1, and a three-plugging and two-grouting hole sealing device is installed on a gas extraction pipe 4 with a diameter of 75 mm, the three-plugging and two-grouting hole sealing device is provided with a bag 5, a biological grouting pipe 6, a biological grouting pipe 7, a biological cement grouting pipe 10 and a biological cement grouting pipe 11, the grouting pipes and the grouting pipes are aligned with the gas extraction pipe 4 in the direction close to the outer end of the drilling hole, the centers of the three bags 5 are spaced apart by 4 m and 14 m, and the outermost bag is spaced apart from the outer end of the gas extraction pipe 4 by 1 m; the gas extraction pipe 4 is sent into the drilling hole 3, 0.5 m is reserved at the outer end of the drilling hole, the biological grouting pipe 6 is 4 m long, the biological cement grouting pipe 10 is 19.5 m long, the biological grouting pipe 7 is 5 m long, and the biological cement grouting pipe 11 is 18 m long.

[0045] Further, the biological liquid 14 with mineralization ability is prepared through a microbial fermentation tank 25. The biological liquid 14 is fully fermented in the fermentation tank, so as to have good mineralization ability, can react with minerals in the coal body cracks, and form a precipitate to block.

[0046] Further, the flow control valve 23 is opened, the biological liquid 14 is transported to the mining stirring grouting pump 22 through the biological liquid conveying pipe 24, after the required flow is reached, the flow control valve 23 is closed, the mixing stirrer 21 is opened, the biological liquid 14 is mixed and stirred with the prepared cement material, and uniform slurry is formed.

[0047] Further, the biological cement grouting pipe valve 12 and the grouting pump 19 are opened, the biological cement slurry 15 is transported to the three-plugging and two-grouting hole sealing device through the biological cement grouting pipe 10. The bag 5 is inflated to form three plugs, two grouting sections are closed in the drilling hole, the pressure is 1.5 MPa, the blasting valve 16 is opened to inject biological cement into the biological cement grouting section 18, until the biological cement flows out of the biological cement grouting pipe 11, and the biological cement grouting pipe valve 12 and the biological cement grouting pipe valve 13 are closed to maintain pressure.

[0048] Further, clean the grouting pump 19, the mixing blender 21, open the flow control valve 23, the biological grouting pipe valve 8, the grouting pump 19, and the biological liquid is transported to the three-plugging two-injection hole sealing device through the biological grouting pipe 6. After flowing out of the biological back grouting pipe 7, close the biological back grouting pipe valve 9 until the pressure reaches 0.5 MPa. Close the grouting pump 19, the flow control valve 23, and the biological grouting pipe valve 8 to maintain pressure.

[0049] Further, with the development of coal body cracks during the extraction process, the biological liquid can be injected multiple times for repair. The flow control valve 23 accurately controls the delivery amount of the biological liquid to ensure that the biological liquid injected each time can effectively seal new cracks, adapt to the dynamic changes during gas extraction, and ensure the stability of the extraction effect.

Claims

1. A three-plug, two-injection plugging device for coal seam gas drainage boreholes based on microbial mineralization, characterized in that, Includes a microbial fermenter (25), a mining mixing grouting pump (22), and a three-plug two-injection sealing device; The three-plug two-injection sealing device includes a bag (5), a biological grouting pipe (6), a biological return grouting pipe (7), a biological cement grouting pipe (10), and a biological cement return grouting pipe (11). The three-plug two-injection sealing device is installed on a gas extraction pipe (4), which is located in a borehole (3) in a pre-extraction coal seam (1). The three bags (5) are arranged in the borehole (3) at intervals, dividing the coal fracture development area (2) near the borehole into a biological grouting section (17) and a biological cement grouting section (18). The outer ends of the biological grouting pipe (6), the biological return grouting pipe (7), the biological cement grouting pipe (10), and the biological cement return grouting pipe (11) are aligned with the gas extraction pipe (4). The inner ends of the biological grouting pipe (6) and the biological return grouting pipe (7) are located in the biological grouting section (17), and the biological cement grouting pipe (10) and the biological cement return grouting pipe (11) are located in the biological cement grouting section (18). The microbial fermenter (25) is equipped with an air inlet pipe (26), a liquid outlet (27), an air outlet (28), a fermenter valve (30), and a liquid inlet (31), and is equipped with a biological liquid mixer (29) inside. The microbial fermenter (25) is connected to the mining stirring grouting pump (22) through the biological liquid delivery pipe (24) and the flow control valve (23) to deliver the biological liquid (14) into the mining stirring grouting pump (22); The mining mixing grouting pump (22) is equipped with a mixing mixer (21), and the mining mixing grouting pump (22) is also connected to the grouting pump (19); the mining mixing grouting pump (22) is connected to the biological grouting pipe (6) and the biological cement grouting pipe (10) respectively through a one-to-two valve (20).

2. The three-plug, two-injection plugging device for coal seam gas drainage boreholes based on microbial mineralization according to claim 1, characterized in that, The biological grouting pipe (6) and the biological cement grouting pipe (10) are respectively equipped with a biological grouting pipe valve (8) and a biological cement grouting pipe valve (12); The biological return pipe (7) is equipped with a biological return pipe valve (9); the biological cement return pipe (11) is equipped with a biological cement return pipe valve (13); the biological cement grouting pipe (10) is also equipped with a burst valve (16); the burst valve (16) is located inside the biological cement grouting section (18).

3. The three-plug, two-injection plugging device for coal seam gas drainage boreholes based on microbial mineralization according to claim 1, characterized in that, The biological cement grouting section (18) is not less than 10m, and the biological grouting section (17) is not less than 3m; the distance between the bladder and the orifice is not less than 0.5m; The three bags (5) are spaced 4m and 14m apart, respectively. The outermost bag is 1m away from the outer end of the gas extraction pipe (4). The gas extraction pipe (4) is sent into the borehole (3) and left 0.5m at the outer end of the borehole. The biological grouting pipe (6) is 4m long, the biological cement grouting pipe (10) is 19.5m long, the biological grout return pipe (7) is 5m long, and the biological cement grout return pipe (11) is 18m long.

Images