Development of Measurement While Drilling (MWD) System for Geothermal Wells

Abstract

In 1991, New Energy and Industrial Technology Development Organization (NEDO) commenced development of the Measurement While Drilling (MWD) system which is capable of providing real-time acquisition of bottomhole data (azimuth, inclination, toolface, temperature, etc.) while drilling wells. In 1998, we conducted well testing at the Kashiwazaki field to evaluate the performance of each component of the MWD system. During the investigation, we succeeded in transmitting mud pulse to the surface from a depth of about 500 meters. In addition, it was revealed that the mud pulse decoding techniques must be improved with respect to drilling noise interference. In 1999, we conducted another well testing to confirm heat resistance of the sonde.