| 摘要 |
<p>A downhole tool for connection in a work string to prevent premature activation of weight set tools on the work string. The tool has moveable pads (34) which contact the tubing wall and thereby support the weight of the work string. The pads (34) are activated by increasing fluid pressure in the annulus between the tool and tubing wall and deactivated by increasing fluid pressure through the central bore of the tool. The tool has ports (48,54) communicating tubing pressure to a front surface of the pad and annulus pressure to a back surface of the pad.</p> |
