DRILL BIT WITH HYDRAULICALLY ADJUSTABLE AXIAL PAD FOR CONTROLLING TORSIONAL FLUCTUATIONS

摘要

In one aspect, a drill bit is disclosed that, in one configuration, includes one or more cutters on a surface thereon configured to penetrate into a formation, at least one pad at the surface, an actuation device configured to supply a fluid under pressure to the pad to extend the pad from the surface, and a relief device configured to drain fluid supplied to the pad to reduce the pressure on the at least one pad when the force applied on the at least one pad exceeds a selected limit.