| 摘要 |
<p>A method for allowing entry of an existing lateral offshoot from a main borehole, without removal of downstream completion tubing from the main borehole, comprising the use of both a liner (14) and a whipstock (28) inserted through the completion tubing (10) to a position within the liner (14), characterised in that an intermediate device (18) has been provided which, in use, is located between the liner (14) and the whipstock (28) so that the whipstock (28) merely needs to locate with the intermediate device (18) rather than the liner (14), the intermediate device (18) preferably having a passageway extending linearly therethrough, and the whipstock (28) preferably being provided with locator keys which are of different profile for different intermediate devices (18).</p> |
