The Accomplishments of Air and Gas Drilling
There are two accomplishments of air and gas drilling: a new series of economic and mechanical challenges; and, acceptance as a standard drilling and completion tool. The new challenges are related to the concept of using a gaseous circulating medium in drilling for oil or gas. For purposes of discussion, a two part division has been made: the challenge of fluid invasion control and that of equipment and tools. Great strides have been made in the development of materials and techniques to combat formation fluid invasion. Chemicals and the "mist drilling" technique, now in use, have the versatility to cope with a wide range of downhole fluid entry conditions. Equipment and tools have been developed to meet the challenges of better, more economic drilling and completion possible with a gaseous circulating fluid. Economic and operational challenges remain. Acceptance of air and gas drilling as a normal operating tool was reached with difficulty. It is now established as a means of reducing costs in exploratory and developmental well drilling, exemplified in a recent study of 226 wells covering 419,407 feet of hole in the United States. Air reached the projected depth in 85 per cent of the operations, although formation water was encountered in 48.7 per cent of the holes. Slim hole bit performance and cost all compared for overall bit averages as part of analysis
Keywords:
Air, Air Drilling, corrosion inhibitor, formation fluid, natural gas, Petroleum Industry, Bits, Challenges, Cost, Costs, Drilling, Fluids, formation, Water, Waters
