| 摘要 |
<p>A downhole adjustable stabilizer (10) and method are disclosed for use in a well bore and along a drill string having a bit at the lower end thereof. A plurality of stabilizer blades (40) are radially movable with respect to the stabilizer body, with outward movement of each stabilizer blade being in response to a radially movable piston (34) positioned inwardly of a corresponding blade and subject to the pressure differential between the interior of the stabilizer and the well bore. A locking member (28) is axially movable from an unlocked position to a locked position, such that the stabilizer blades may be locked in either their retracted or expanded positions. In the preferred embodiment of the invention, the stabilizer may be sequenced from a blade expanded position to a blade retracted position by turning on and off a mud pump at the surface.</p> |
