Patent ID: 6823944
Filing Date: 2004-11-30
Classification: E21B

Abstract:
An apparatus for sealing the top of a liner within a casing string of an oil well where the apparatus, in combination with a liner attached to the bottom of the apparatus, is run into the well on a work string until the bottom of the liner sets on the bottom of the well, the apparatus comprising:(a) a hollow cylindrical mandrel comprising an inside surface, an exterior surface, a first end and a second end, the first end and second end defining a longitudinal axis, the first end having a first set of internal threads adapted to engage a run-in tool attached to the work string and the second end is adapted to connect to the top of the liner; (b) the exterior surface comprising a wicker section having a plurality of first wicker members disposed circumferentially about the mandrel; (c) the mandrel further comprising a plurality of slots extending from the inside surface to the exterior surface, each slot having a major axis coincidental with the longitudinal axis; (d) an outer cylindrical housing, a cylindrical lock ring, a cylindrical sealing element, and a cylindrical slip ring, said housing, lock ring, sealing element and slip ring each having an inside diameter and slidably disposed on the exterior surface of the mandrel along the longitudinal axis in relative order, the lock ring adjacent to the wicker section; (e) the outer cylindrical housing further comprising a top end, the top end adjacent to the first end of the mandrel, the top end having a second set of internal threads adapted to engage the run-in tool when the run-in tool is disengaged from the first set of internal threads, the housing further comprising a plurality of tapped holes extending through the wall of the housing, each hole configured to overlay one of the slots of the mandrel; (f) the lock ring comprising an inside surface comprising a plurality of second wicker members adapted to engage one or more of the first wicker members of the mandrel; and (g) a plurality of lugs for insertion into the holes and coinciding slots, each lug having a head and a body section, the body section being threaded to be received by the tapped hole, each lug having a length such that the body section extends into the slot but does not penetrate beyond the interior surface.