| 摘要 |
This invention relates to a steerable drill bit arrangement, in particular for the use in drilling boreholes for oil and gas extraction. There is provided a steerable drill bit arrangement in which the drill bit ( 20 ) is connected to a drill string ( 16 ) including a steering component ( 12 ) and a stabiliser ( 14 ), the stabiliser ( 14 ) being located between the steering component ( 12 ) and the drill bit ( 20 ), the steering component ( 12 ) being adapted to move the drill string ( 16 ) transversely relative to a borehole in which it is located, the stabiliser ( 14 ) having an inner part ( 32 ) adapted to rotate with the drill string ( 16 ) and an outer part ( 34 ) adapted to engage the borehole wall, the outer part ( 34 ) being rotatable relative to the inner part so that the outer part ( 34 ) can remain substantially stationary as the remainder of the stabiliser ( 14 ) rotates with the drill string ( 16 ).
|
