| 摘要 |
Rotary steerable drilling tool (9) having a tool collar (24) and a bit shaft (23). The bit shaft (23) is supported within the tool collar (24) for pivotal movement about a fixed position along the bit shaft (23). The rotary steerable drilling tool (9) includes a variable bit shaft angulating mechanism (16), located within the interior of the tool collar (24). The variable bit shaft angulating mechanism (16) includes a motor, an offset mandrel (30), and a variable offset coupling (31). The motor is attached to the upper end of the offset mandrel (30) and adapted to rotate the offset mandrel (30). The upper end of the variable offset coupling (31) is uncoupleably attached to an offset location of the lower end of the offset mandrel (30), and the upper end of the bit shaft (23) is rotatably coupled to the variable offset coupling (31). The rotary steerable drilling tool (9) also includes a torque transmitting coupling (17) adapted to transmit torque from the tool collar (24) to the bit shaft (23) at the fixed position along the bit shaft. A seal system (14) is adapted to seal between the lower end of the tool collar (24) and the bit shaft (23). <IMAGE> |
