摘要 |
A coiled tubing directional drilling apparatus which is operated by a mud motor and is characterized by a fixed housing and a rotary steerable bent housing or sub which is selectively rotatable with respect to the fixed housing at a fixed angle bend by a shifting mechanism, typically operated by a reversible electric motor. The motor and shifting mechanism rotate with the drive shaft and employ a lead screw in a cross-nut arrangement that selectively engages and disengages a castle lock or power take-off drive system responsive to the direction of rotation of the motor, for effecting 360-degree rotation of the bent housing with respect to the fixed housing. A sun gear and pinion gear planetary gear system facilitate rotation of the bent housing with respect to the fixed housing at a slower speed than the drive train and bit box components of the device.
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