Some geomechanical aspects of gas recovery from coal seams

The evolution of stress and pressure fields during gas recovery from coal s eams is studied on the basis of a three-dimensional geomechanical model of coherent filtration. It is shown that one can change the stressed-strained state of rock mass and control purposefully the rate of process by creating an elliptical cavity in the vicinity of borehole face; the axes of this ca vity are oriented with respect to the direction of principal horizontal str esses in the natural field. The tendency of developing disintegration zones that are within surrounding rocks during degassing of seams is investigate d in relation to the lateral pressure coefficient.