Downhole apparatus and method for expanding a tubing

摘要

PCT No. PCT/GB96/02903 Sec. 371 Date May 21, 1998 Sec. 102(e) Date May 21, 1998 PCT Filed Nov. 25, 1996 PCT Pub. No. WO97/20130 PCT Pub. Date Jun. 5, 1997Downhole apparatus is disclosed for use in expanding liner or tubing. The apparatus comprises a body for connection to a string and an expansion portion on the body. The expansion portion includes a plurality of radially movable parts for defining an outer surface thereof. The parts are initially arranged in an axially and circumferentially offset first configuration in which the parts may assume a smaller diameter first configuration. The apparatus is then run Into a borehole and through a length of expandable tubing. The parts are the moved radially outwardly and axially aligned such that the parts assume a larger diameter second configuration and define a substantially continuous outer circumference. The expansion portion is then pulled through the tubing to expand the tubing.