Apparatus And Method For Damping Vibration In A Drill String

摘要: An apparatus and method for damping vibration, especially torsional vibration due to stick-slip, in a drill string. Sensors measure the instantaneous angular velocity of string at one or more locations along length One modules are also spaced When above threshold is detected, module imposes reverse torque on that dampens vibration. The can be created by imparting frictional resistance rotation externally, extending friction pads from so they contact bore hole wall drag as rotates, internally anchoring housing mounted then imposing fluid, such magnetorheological flowing within