HYBRID PUSH AND PULL METHOD AND SYSTEM FOR EXPANDING WELL TUBULARS

摘要

A hybrid push and pull method for expanding a tubular in a wellbore utilizes an expansion assembly with a sealed (3) and another, optionally expandable (2), cone, wherein during at least part of the expansion process the sealed cone (3) is moved up through the tubular by a combination of push and pull forces and the push force is generated by pumping fluid at an elevated pressure into a space between the bottom plug (1) and the expansion assembly. This allows staged expansion of the tubular in a hard rock formation and/or of a tubular surrounded by a hardened cement lining and/or of a pair of partially overlapping nested tubular ends.