Gas emission quantity prediction and drainage technology of steeply inclined and extremely thick coal seams

摘要

Gas emissions of workfaces in steeply inclined and extremely thick coal seams differ from those under normal geological conditions, which usually feature a high gas concentration and a large emission quan-tity. This study took the Wudong coal mine in Xinjiang province of China as a typical case. The gas occur-rence of the coal seam and the pressure-relief range of the surrounding rock (coal) were studied by experiments and numerical simulations. Then, a new method to calculate the gas emission quantity for this special geological condition was provided. Based on the calculated quantity, a further gas drai-nage plan, as well as the evaluation of it with field drainage data, was finally given. The results are impor-tant for engineers to reasonably plan the gas drainage boreholes of steeply inclined and extremely thick coal seams.