Efficient blasting relieved drainage method for covered roadway on low-permeability high-gas coal bed

Abstract

The invention provides an efficient blasting relieved drainage method for a covered roadway on a low-permeability high-gas coal bed. The method is characterized in that a parallel floor roadway is built below a covered roadway coal bed; gas pumping holes are formed in the floor roadway by covering the covered roadway coal bed upwards for pumping; 2 to 3 blasting holes are formed between adjacent groups of pumping holes; after the blasting holes are filled with an explosive, water is injected for explosion; the quantity of the blasting holes which explode at one time is not less than 6. Stress waves are formed in coal rock through high-pressure shock waves generated by water coupled charge explosion under the resonance action of the plurality of blasting holes in simultaneous blasting in order to crack the coal rock, gas in the coal bed is replaced with a large amount of CO2 an N2 generated by explosion of the explosive, and a water injection pipe and a gas pumping pipeline are connected for pumping 0.5 hour after explosion. By adopting the method, an efficient blasting permeability-improving pumping technology of the covered roadway on the low-permeability high-gas coal bed is implemented, and operation becomes easy, convenient and feasible.

Description

technical field [0001] The invention relates to the technical field of gas drainage in coal seams, in particular to a method for efficient pressure relief and drainage in a sheltered roadway of a low-permeability and high-gas coal seam. Background technique [0002] Most mining areas in my country have entered into deep mining, where the in-situ stress of deep coal seams increases, the air permeability of coal seams is lower, and it is more difficult to extract gas. The deep hole loosening blasting technology has the advantages of wide application range and obvious anti-reflection effect, and has become an effective technical approach for anti-permeability enhancement in deep low-permeability coal seams. [0003] At present, the deep hole loosening blasting technology adopted in China mostly adopts the way of charge initiation in coal seam. Although this method can greatly improve the gas permeability of the coal seam in a short period of time and enhance the efficiency of ...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a method of high-efficiency blasting and pressure-relief extraction in the sheltered roadway of low-permeability and high-gas coal seams, so as to overcome the small disturbance of coal seam charge blasting, the small range of influence of the fracture network, and the poor effect of permeability enhancement and pressure relief. And other issues

However, at present, there are no research issues related to the regional pressure relief and permeability enhancement method of water injection blasting across the coal-rock interface in China.

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