Experimental Study on Gas Extraction Methods in Sichuan Basin Xujiahe Formation Extremely Thin Coal Seam

Based on complex geological structure and poor gas-permeability in Sichuan basin Upper Triassic Xujiahe formation, the gas extraction methods and their effect were demonstrated in Wangyang, Yangcunpu, Shengli et al. coal-mines. Research results showed that the gas extraction method from holes drilled along seam had good effect on geological structural section in highly gassy coal mines mined Xujiahe extremely thin coal seam. The gas extraction method with pressure relief from the roof and/or floor crossing holes had better extraction effect, was main gas extraction method in Sichuan basin coal mines.