| 摘要 |
<p>A centraliser (1) comprises an upper ring (2) and a lower ring (3) connected by six rigid members (4). The centraliser (1) can be mounted on casing to be lowered down deviated bores. The rigid members (4) are designed to collapse under a lateral load of about 8 tonnes. Thus if, for example, part of the bore collapses and the casing has to be withdrawn the rigid members will collapse enabling the centraliser (1) to be recovered on the casing in one piece.</p> |
