Marvin Gearhart, Gearhart Industries Inc.
One of the more extensive uses of directional drilling anywhere in the world has been in the development of the East Wilmington Oil Field in Long Beach, California. The average well achieves a deviation from vertical in excess of 50' and wells with a build-up in the 70 to 80 range are not uncommon before they are dropped off to 50 or less when penetrating the completion interval. Over 780 wells have been drilled in this field to date, requiring the highest degree of control and accuracy in order to avoid intersection of other wells and to obtain proper bottom hole spacing. The Measurement-While-Drilling (MWD) directional system has been tested on several wells and proven to provide the required accuracy along with many advantages over past methods used in the field development. Accurate transmission by MWD of bottom hole measurements to the surface is provided by mud pressure pulses generated in the drill pipe downhole and detected by a pressure transducer mounted on the standpipe. Surface equipment includes the means for detecting, recording and processing these pressure pulses, to translate the information from the pressure pulses to rig floor displays useable by the drilling crew.