Protective seam mining released range and the site deployment of the released methane draining surface well in Huainan mine area

Based on data from protective seam mining and released methane surface drainage engineering practices, combined with the deformation and displacement detection of the overlying strata in mining area and the rock mechanical properties testing results of the coal seam in laboratory, the paper summarizes the geology conditions of mining coal and coal bed methane, discusses the method of determining the efficient released ranges and obtains the results of the ranges, analyzes the released ranges' influence on the released methane surface well site deployment and presents suggestion about that.The findings indicate that 11-2 coal's maximum protective distance is 177 m in Huainan mine area, the released angle along the strike is 64°, along the dip the angle in inferior part is 77°, in superior part is 83°, relative to 11-2 coal, the released range of 13-1 coal along the dip retracts inwards 15.4 m in inferior part, in superior part retracts inwards 8.2 m, the surface well should be deployed at 37 m far from start-mining line along the strike and close to return airway about 13~30 m along the dip.The findings are significant for realizing coal bed methane drainage efficiently, stably, continuously and simultaneously extracting coal and coal bed methane.