| 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 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. |
