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 downholemotor-based bottomhole assembly with a bit deflection device includes a torquecompensation device and is secured to the drill string via a swivel to permitindependentrotation of the string and the bottomhole assembly. In the case of a drillpipe string, thestring may be rotated continuously during both linear and nonlinear drillingto reducedrag. In the case of a tubing string, the bottomhole assembly is rotated bythe torquecompensation device during straight drilling. In both cases, the torquecompensationdevice is employed to adjust TFO for nonlinear drilling when the bottomholeassembly isnot rotated. In an alternative embodiment, a torque-sensitive clutch isemployed in lieuof the torque compensation device to provide rotational orientation to, androtation o~the bottomhole assembly.