DETERMINATION OF THE ORIENTATION OF A DOWHOLE DEVICE

摘要

For measuring the orientation of an offset stabiliser device in a downhole environment. A shaft rotates relative to the stabiliser device, and signal trigger means are provided at known locations on each of the rotating shaft and the stabiliser device. When the signal trigger means on each component a re brought into alignment, a signal is triggered and a pressure pulse is generated. The timing of the generated signals are used together with the measured orientation of the shaft, obtained using an angular measurement sensor such as an accelerometer and/or magnetometer, in order to calculate t he orientation of the offset stabiliser device.