APPARATUS FOR ANGULAR ALIGNMENT OF DOWNHOLE SENSORS WITH HIGH SIDE IN DIRECTIONAL DRILLING

摘要

Adjustment of the angle of a bent sub or other steering feature in a drill string relative to a reference angle of a downhole sensor is facilitated by a rotatable coupling between the bend sub and the sensor. The rotatable coupling may be rotated to align the high side with a reference indicia and locked at the set angle. Calibration of the sensor is facilitated and opportunities for certain measurement errors are eliminated. An embodiment provides a locking mechanism comprising tapered locking fingers which are clamped against a surface by a tapered collar. Rows of ceramic balls retained in circumferential channels may be provided to permit rotation while carrying tensile and compressional forces.