Gas Drainage Characteristics Under Regional Water Bearing Conditions and Numerical Simulation

Guqiao Mine 4^# coal seam in soft outburst coal seam was infiltrated by sandstone fissure water, and gas drainage was affected. In order to study the gas drainage laws of regional coal seam containing water, COMSOL Multiphysics was used to simulate the gas pressure change under different water content and gas drainage radius; simulation results show that the drainage radius is 3.1 m and 1.8 m respectively, when the moisture content is 1.73% and 5.68%; the higher of water content, the smaller of decreasing gradient of gas pressure. Through field test study of coal seam permeability and adsorption properties under the influence of different moisture content and stress, by the evidence of Guqiao Mine 4^# coal seam, the gas drainage radius of coal seam containing water was reduced by 70.9%, the initial concentration of gas drainage was reduced by 50%, and gas drainage of single hole was decreased by 75%.