| 摘要 |
A subsurface wellbore 20 includes at least one expandable sleeve (liner) 27 that is fully overlapped by a non expandable sleeve (liner) 28 such that the interior of the wellbore is cased entirely by the non expandable sleeve. 28 In use, the wellbore 20 is drilled then an expandable sleeve 27 is expanded into contact with the wellbore wall to form a temporary support for the wall. The well is then drilled further and the wellbore is cased with a non expandable sleeve 28 which fully overlaps the expandable sleeve 27. Also claimed is a wellbore that includes a wellhead (34, fig 3), a tubing hanger (33, fig 3) located in the wellhead (34, fig 3) and a number of liners, wherein the wellbore does not include a casing hanger. The wellhead also includes holes (34a fig 3) such that downhole liners can be passed through the wellhead (34, fig 3). The arrangements are said to be suitable for use in slimhole or narrow well drilling. |
