Drilling deviation control tool

摘要

A body, functioning as a length of drill string, has an eccentric roller mounted for rotation around the body. The roller and body have cooperating cam surfaces that cause the roller to reciprocate axially when the body rotates relative to the roller. In use, the extended radius of the eccentric roller engages the near side of the well bore walland tends to become stationary relative to earth. The forced axial motion of the retarded roller induces some peripheral motion at each turn of the drill string. The eccentric roller turns freely with the drill string when the extended radius is adjacent the far side of the well bore wall. The extended radius of the roller tends to spend most of the drilling time between the drill string and the near side, or low side, of the well bore to aid in well bore deviation control.