Retrievable packer for high temperature, high pressure service

Abstract

In a retrievable packer adapted for service under high temperature and pressure conditions, improved sealing is provided by a seal element prop surface which is radially offset with respect to the seal element support surface of the packer body mandrel. At least one seal element is supported on the elevated prop surface and is subjected to a radial squeeze in the set configuration, even though the lowermost seal element may be subject to longitudinal separation. The split level seal element support arrangement provides an annular pocket into which the seal elements can be retracted upon release and retrieval of the packer, thereby providing clearance for unobstructed retrieval. Upon release of the packer, a retainer collar is shifted away from a lower metal backup shoe, thereby providing an annular pocket into which the metal backup shoe is deflected, so that it does not obstruct the drift clearance as the packer is retrieved. Preloading of the seal element assembly is provided by a cover sleeve which releases, and longitudinally moves along the body mandrel, when a predetermined amount of longitudinal seal compression has been achieved. The cover sleeve carries, for longitudinal movement therewith, an upper metal backup shoe positioned to be engaged and deformed by the upper end of the seal element assembly.