Application research on gas drainage technology at low permeability coal seam

Gas drainage at low gas permeability coal seams is a main barrier affecting safety and efficient production in coal mines. The research and application of drainage technology in low gas permeability coal seams is key for coal mine gas control. In order to improve the drainage effect, this paper establishes a three-dimensional solid-gas-liquid coupling numerical model and studies the gas drainage amount of different schemes inside the overburdened rock around the goaf. Yangquan mine area is chosen as the research target, and the gas movement regularity and emission characteristics are comprehensively analyzed, as well as the stress and fissure variation regularity, the scope of released gas movement, enrichment range, and movement regularity during coal extraction. Then the gas drainage technology and parameters for the current coal seam are studied. After measuring the gas drainage amount in-situ, it was found that the technology can achieve notable drainage results, where gas drainage rate increase by 30%similar to 40% for low permeability coal seams.