Abstract:
Surface gas extraction will be the main way of gas extraction in coal mine. The selection of well-type has become the difficulty of gas extraction. In order to find a set of appropriate well-type to Dafosi Coal Mine, this article has researched the storage characteristics of the mine. It is found that the adsorption capacity and permeability in Dafosi Coal Mine are better than many mines. Different coal seams show difference in adsorption capacity and permeability at the same coal mine. Thus, the well type of "U", "V" and multiple branches are proposed to improve the gas extraction volume.