Method for reducing contaminant emissions in gas drilling operations

摘要

An improved gas drilling method for drilling a well through steam- bearing formations in which emissions of particulate material and other contaminants are reduced by imposing a surface back pressure on, and thereby reducing the velocity of, the contaminant-bearing gas rising through the well. The drilling cuttings and other particulate material rising through the well are subjected to less abrasion and therefore arrive at the surface as larger, more easily separated particles. Drill string erosion is also reduced by the method and the efficiencies of any well effluent treatment facilities are increased.