The three-in-one gas drainage method of drilling, blasting and pumping

Abstract

A three-in-one gas drainage method of drilling, blasting and pumping is most suitable for regional gas drainage in high-gas and low-permeability coal seams. On the coal seam in front of the coal mining or excavation face, the drainage holes and blasting holes are alternately arranged in the same layer or through the layer; the construction operation is performed on the drainage holes one by one, and the cutting and gas extraction are carried out; the blasting holes are constructed one by one, And carry out the blasting operation, through the sharpening action of the blasting gas in the blasting hole, a columnar compressed crushing ring and a penetrating blasting fracture body along the direction of the blasting hole and the drainage hole connecting the center line are formed around the blasting hole, so that the ground stress is transferred, the coal body The air permeability increases, and the internal pressure of the coal body is relieved, which is beneficial to the discharge of gas in the coal body. The gas permeability of the coal body can be increased by about 20-50 times, the gas drainage volume of a single hole can be increased by 5-10 times on average, the gas drainage concentration is ≥50%, the gas drainage rate of the mining face is ≥80%, and the drilling and blasting pumping pressure relief After anti-reflection, the pre-gas extraction time can be shortened by half, and the number of gas drainage drilling holes can be reduced by 20-30%. Realize the safe, efficient and uniform extraction of high-gas and low-permeability outburst coal seam gas.

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

Images