DIFFERENTIAL SENSOR MEASUREMENTS TO DETECT DRILL BIT FAILURE

摘要

An apparatus and accompanying method for monitoring and reporting downhole bit failure. Individual sensors (106) are placed on a sub (104) which is separate from the drill bit (108) itself, and are powered by a vibration driven power system. The sensor readings are used to compute values which represent the ratios of sensor readings on one sensor (106) in relation to the readings on one or more other sensors (106). This creates a self-calibrating sensor system that accounts for changes in downhole conditions which might cause sensor readings to fluctuate, but which do not indicate failure.