Method for extracting protruded coal-bed downward bedding long-borehole step-by-step covering area gas

Abstract

This is a gas extraction method for a single burst coal bed of stable coal occurrence, angle less than 10o, and firm index over 0.5. Drill a hole from top working face downward along the coal bed from shallow bed to deep, from low gas concentration zone to high for pre-extraction to lower down the gas concentration.

Description

technical field [0001] The invention relates to a regional gas drainage method for progressively covering long boreholes under an outburst coal seam, especially suitable for regional gas drainage of a single outburst coal seam with stable coal seam occurrence, dip angle less than 10°, and firmness coefficient greater than 0.5 . Background technique [0002] As the mining depth of coal seams increases, the gas pressure and gas content of coal seams increase, and some coal seams transform into outburst coal seams. According to relevant national regulations, gas drainage should be carried out before the mining of outburst coal seams. The commonly used regional gas drainage methods include mining of protective layers and pre-draining of coal seams in floor rock roadways, but these two drainage methods have long construction periods and high costs. . Contents of the invention [0003] In view of the problems existing in ...

AI Technical Summary

Problems solved by technology

According to relevant national regulations, gas drainage should be carried out before the mining of outburst coal seams. The commonly used regional gas drainage methods include mining of protective layers and pre-draining of coal seams in floor rock roadways, but these two drainage methods have long construction periods and high costs.