Drilling-explosion-pumping triadic gas extraction method

Abstract

The invention relates to a drilling-explosion-pumping triadic gas extraction method, which is most suitable for regional gas extraction of a high gas and low permeability coal seam. The method comprises the following steps: alternately arranging hole positions of drainage holes and blast holes of an along bed or a cross seam on a coal seam in front of a coal mining or tunneling working surface; and performing construction work on the drainage holes one by one, and performing blasting operation, wherein through the edgetone effect of denotation gas in the blast holes, a columnar compression crushing circle and a crack body which passes through and blasts in the direction of a line of centers of the blast holes and the extraction holes are generated on the periphery of a blasting hole to transfer the ground stress, improve the gas permeability of a coal body, relieve the pressure in a coal body and facilitate for drainage of gas in the coal body. The gas permeability of the coal body can be improve by around 20 to 50 times, the gas extraction quantity of haplopore can be increased by 5 to 10 times averagely, the gas extraction concentration is more than or equal to 50 percent, and the gas extraction rate of a robbing working surface is more than or equal to 80 percent. After pressure releasing and permeability improving of drilling, explosion and pumping, the gas pre-extraction time can be shortened by half, and the number of drilling holes of gas extraction is decreased by 20 to 30 percent; and the method achieves safe, high-efficiency and uniform extraction of the gas in the high gas and low permeability outburst coal seam.

Description

technical field [0001] The invention relates to a three-in-one gas drainage method of drilling, blasting and pumping, and is especially suitable for regional gas drainage of high-gas and low-permeability coal seams. Background technique [0002] The mining of high-gassy and low-permeability coal seams is often accompanied by a large amount of gas emission, especially with the efficient intensification of coal production and the increase of mining depth, the amount of gas emission is increasing, and the threat of gas explosion and gas outburst is increasing. Gas disasters have become the most important factor restricting the development of efficient and intensive mining technology and safe production. Therefore, how to effectively solve the problem of gas gushing in the process of mining high-gas coal seams is of great significance to the safe production of coal mines. Since the 1970s, my country has carried out exploratory experimental research on various gas drainage press...

AI Technical Summary

Problems solved by technology

However, due to the low permeability of high-gassy and low-permeability coal seams, conventional drainage is difficult and the effect is poor, so it is necessary to take technical measures to relieve pressure and increase permeability

At present, the technical measures for pressure relief and anti-reflection of high-gassy and low-permeability coal seams mainly include deep hole loosening blasting, hydraulic punching, hydraulic slotting, and coal seam water injection. Due to the problems of heavy workload and low drainage efficiency, other more effective pressure relief and permeability enhancement methods need to be adopted to expand the effective impact range of drilling and improve the gas drainage effect of this coal seam

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