| 摘要 |
A method of sealing the wall of a wellbore ( 1 ) as it is being drilled through a subterranean formation using a drill string ( 3 ) having a drill bit ( 4 ) on the lower end thereof comprises fitting to the lower end of a drill string ( 3 ) a device comprising (i) a cylindrically gathered pack of flexible tubing ( 6 ), (ii) a receptacle ( 5 ) for the gathered pack and (iii) a radially expandable locking means ( 8 ) having a first end of the tubing of the gathered pack connected either directly or indirectly thereto, and drilling a first section of wellbore, expanding the locking means ( 8 ) against the wellbore wall such that the first end of the tubing that is withdrawn from the gathered pack is locked in place in the wellbore, drilling a second section of wellbore with the movement of the drill string ( 3 ) through the wellbore causing the tubing to be withdrawn from the gathered pack ( 6 ) and to be turned inside out thereby forming a liner for the second section of wellbore.
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