ROTARY STEERABLE DRILLING SYSTEM

摘要

A rotary steerable drilling system includes a gear box driven by a drill string having an input rotatable in a first direction and an output rotatable in an opposite direction. A drive shaft coupled to the output has a first axis of rotation, and a rotatable tubular bit sleeve annularly arranged around a distal portion of the drive shaft is pivotable to have a second axis of rotation and includes a connector assembly on a distal end of the bit sleeve for coupling the bit sleeve to a drill bit. A spherical CV joint couples the bit sleeve to the drive shaft, eccentric cams are movably no positioned on the drive shaft, a differential gearing system is connected to the eccentric cams, and a pressure applying device is connected to the eccentric cams. When activated, the pressure applying device applies pressure to modify the speed of rotation of the eccentric cams. A method of rotary steerable drilling is disclosed.

主权项

1. A rotary steerable drilling system positionable on a rotatable drill string in a wellbore, said rotary steerable system comprising:
a gear box driven by the rotatable drill string, said gear box having a rotary input rotatable in a first rotary direction and a rotary output rotatable in second rotary direction opposite to the first rotary direction; a rotatable drive shaft coupled at a first end to the rotary output of the gear box, said rotatable drive shaft having a first axis of rotation; a pivotable rotatable tubular bit sleeve coupled at a first end to a second end of the rotatable drive shaft, the bit sleeve pivotable to have a second axis of rotation different than the first axis of rotation of the rotatable drive shaft, said pivotable rotatable tubular bit sleeve including a connector assembly on a distal end of the bit sleeve for coupling the bit sleeve to a drill bit; eccentric cams movably positioned on the drive shaft; a differential gearing system connected to the eccentric cams; and pressure applying device connected to the eccentric cams, wherein when activated the pressure applying device applies pressure to modify a speed of rotation of the eccentric cams thereby pivoting the bit sleeve to the second axis of rotation.