Accelerometer caliper while drilling

摘要

An accelerometer caliper while drilling arrangement comprising a drill bit 10 having an axis 12 of rotation and a gauge region 14, a caliper tool body 20, a first accelerometer 24 mounted upon the caliper tool body 20 and arranged to measure acceleration in a first direction 25, and a second accelerometer 28 mounted upon the caliper tool body 20 and arranged to measure acceleration in a second direction 29 orthogonal to the first direction 25, wherein the caliper tool body 20 and the drill bit 10 are coupled to one another in such a manner that the first and second accelerometers 24, 28 are mounted in a known relationship to the drill bit 10.