| 摘要 |
A system and method for drilling is disclosed, the system including a drill string with at least one drill pipe, a bottom hole assembly and a drill bit. The bottom hole assembly includes a downhole mud motor for rotating the drill bit, and a steering motor coupled between the mud motor and the drill pipe. The downhole mud motor includes a bent housing. The drill pipe is continuously rotated to minimize friction, regardless of whether the drill bit is turned using rotary drilling or drilling with the downhole mud motor. Tool face orientation may be controlled by operating the steering motor at the drill pipe speed, but in an opposite rotational direction to thereby hold the mud motor and bent housing stationary with respect to the formation. Steering motor speed may be increased or decreased to adjust tool face orientation. |
