Patent ID: 7798223

Claim:
A method of isolating a section of a drilled bore, the method comprising: forming an unlined section of the drilled bore and enlarging a section of the unlined section; disposing a tubing with an expander operatively coupled thereto into the drilled bore; locating at least a portion of the tubing in the unlined section of the drilled bore to be isolated, wherein the portion of tubing comprises an outer relatively deformable layer; and expanding the portion of the tubing into circumferential contact with a wall of the unlined section by using the expander such that the expanded portion conforms to irregularities in the wall of the unlined section of the drilled bore, wherein the outer relatively deformable layer extends across the irregularities in the wall and a section of the portion of the tubing is located in the enlarged section of the unlined section, wherein the enlarged section has a larger diameter than the unlined section.