METHOD AND APPARATUS FOR NAVIGATIONAL DRILLING WITH A DOWNHOLE MOTOR EMPLOYING INDEPENDENT DRILL STRING AND BOTTOMHOLE ASSEMBLY ROTARY ORIENTATION AND ROTATION

摘要

A subterranean drilling assembly for linear and nonlinear drilling. A downho le motor-based bottomhole assembly with a bit deflection device includes a torq ue compensation device and is secured to the drill string via a swivel to permi t independent rotation of the string and the bottomhole assembly. In the case of a drill pipe string, the string may be rotated continuously during both linear and nonlinear drilling to reduce drag. In the case of a tubing string, the bottomhole assembly is rotated by the torque compensation device during straight drilling. In both cases, the torque compensation device is employed to adjust TFO for nonlinear drilling when the bottomhole assembly is not rotated. In an alternative embodiment, a torque-sensitive clutch is employed in lieu of the torque compensation device to provide rotational orientation to, and rotation o~ the bottomhole assembly.