Sealed junction having a side pocket

摘要

A sealed junction in a multilateral well structure comprises a primary borehole, at least one casing segment disposed in the borehole at a predetermined position, the segment having a pre machined window. A side pocket 42 is provided adjacent the window, the side pocket being movable between a position substantially enveloped by the casing segment (figs 7 and 9) and a position where the side pocket is sealed against the window and protrudes from the segment (figs 8 and 10).