| 摘要 |
<p>A variable angle directional drilling "sub" provides a shifting end portion which allows the sub to be rotated from a first, in-line, axially straight orientation with the drill string to a selected second, angled or "bent" position. The tool (10) provides a multiple choice of varying angles to the sub in its bent position to satisfy differing directional drilling situations. A first embodiment (Figs. 1-7) is manually set and varied at the surface by positioning two angularly marked section (70, 71) temporarily rotatable with respect to each other until the desired angle set is matched up, while a second embodiment (Figs. 8-9) is motor driven to allow varying the angle direction while "down in the hole". The device rotatably shifts about an off-set axis of rotation of sleeve (20) with axis (40a) of movable connection (40) from the first (in-line) position aligned with axis (12a) of barrel (12) to the second (bent) position with these axes misaligned either (in the first manually adjustable embodiment) upon the application of torsional force thereto, which torsional force can be applied, for example, by the actuation of a "turbodrill" (102) (normally attached in operation), or (in the second motorized embodiment) by an electrical signal from the surface to a built-in motor contained within the tool. </p> |
