Abstract: A method of isolating a section of a drilled bore containing a problem zone comprises: providing a section of tubing; locating the tubing in the section of the bore; and expanding the tubing and forming at least an outer portion of the tubing to conform to irregularities in the bore wall, to isolate the problem zone. The tubing may feature a formable outer section, and the expansion of the tubing may be achieved using a compliant rotary expander.

Abstract: The present invention relates to portions of casing that are inserted into a wellbore. The casing portions are provided with a protected portion in which a friction and/or sealing material can be located. In certain embodiments, the protected portion is provided by first and second annular shoulders that are spaced-apart axially along the length of the casing. The friction and/or sealing material is typically located on an outer surface of the casing between the annular shoulders. There is also provided a casing portion that has annular shoulders provided at either end of the casing portion, with means to connect successive casing portions located on these shoulders. The casing portion in this embodiment is provided with a friction and/or sealing material in a recessed portion of the casing portion.