Sealing device for high-gas soft coal seam drilling and sealing method thereof

Abstract

The invention discloses a sealing device for high-gas soft coal seam drilling and a sealing method thereof. The sealing device comprises a reinforcing supporting layer, a sealing layer and an extraction pipe which are concentrically distributed. The reinforcing supporting layer comprises a first bag, a first grouting pipe and a first slurry return pipe, a first one-way valve is arranged on the first grouting pipe, one end of the first grouting pipe is provided with a first quick joint, the other end of the first grouting pipe is provided with a first blasting valve, and the first slurry returnpipe is provided with a first stop valve. The sealing layer comprises a second bag, a third bag, a second grouting pipe and a second grouting pipe, the second grouting pipe is provided with a secondone-way valve, a third one-way valve and a second blasting valve, one end of the second grouting pipe is provided with a second quick joint, and the second grouting pipe is provided with a second stopvalve. The sealing device is simple in structure, reasonable in design, convenient to use and low in cost, can be effectively applied to sealed extraction of high-gas soft coal seam drilling, and isgood in use effect and convenient to use and popularize.

Description

technical field [0001] The invention belongs to the technical field of drilling hole sealing for gas drainage, and in particular relates to a sealing device and a sealing method for drilling holes in high-gas soft coal seams. Background technique [0002] Borehole drainage is one of the basic technical means of coal mine gas control and has a wide range of applications. However, due to the destruction of the geological structure during the coalification process, the high-gassy soft coal seam is generally soft and soft. In addition, due to the effect of gas pressure, the sealing section is prone to instability and deformation after the construction of drainage drilling, which makes the drilling difficult. Sealed, the effect of gas extraction cannot be guaranteed. In addition to the stability of the sealing section, the sealing quality is another important factor affecting the gas drainage concentration, orifice negative pressure, and even the drainage effect of the entire dr...

AI Technical Summary

Problems solved by technology

Among them, the problem of the traditional "two plugs and one injection" hole sealing method is mainly manifested in: the plug is a separate process in the "two plugs and one injection" process, and it needs to be plugged first, which causes the problem of complicated procedures and increased workload; " The strength of "two plugging" is low, the plugging strength at both ends is low, the effect is poor, the grouting pressure cannot be increased, and even the hole is not sealed with pressure, and the cracks around the drilling cannot be tightly sealed, and the purpose of "injection" cannot be achieved

Polyurethane seals often fail to achieve the ideal sealing state due to insufficient sealing length and difficulty in penetrating into the borehole cracks. The sealing material has certain toxicity and high price, resulting in high sealing cost, which is difficult for coal mines to bear

At the same time, due to the soft quality of coal in many high-gas mines, the problem of hole collapse often occurs during the process of feeding the gas extraction pipe into the borehole, resulting in insufficient length of the sealing section, and the sealing effect cannot be achieved

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