Development Orientation and Status of Key Technology for Mine Underground Coal Bed Methane Drainage as well as Coal and Gas Simultaneous Mining

The paper introduced the key technical system and development status of the mine surface and underground coal bed methane three-dimensional draina ge and the coal and gas simultaneous mining, and pointed out that according to the features of the coal deposit conditions in China, the principle of the underground mi ne and mine surface gas drainage double line should be conducted, the technical bottleneck of the surface coal bed methane drainage should be broken through and th e intensity of the underground mine gas pressure releasing and gas drainage and the coal and gas simultaneous mining should be enhanced.The paper summarized th e present status and development tendency of the present underground mine coal bed methane drainage, the wall construction of the non coal pillar gateway retained a long the goaf, the backfill material preparation and pumping technique of the non coal pillar gateway retained along the goaf, the surrounding rock stability contral of the gateway retained along the goaf, the comprehensive gas control of the gateway retained along the goaf and other technology.The surface well gas drainage and the un derground mine gas drainage could be mutually integrated, with the pressure released effect from the coal mining in the protective seam, the gas well drilled at the surf ace ground could pass through the protective seam, the gas drainage rate of the single well could be highly improved and one gas well with two applications or one gas well with multi applications would be the only way for the near future development of the coal bed methane.