Self-energized seal or centralizer and associated setting and retraction mechanism

摘要

A self energizing structure can function as a centralizer or as a seal when allowed to spring out after a retainer is moved away from an overlying position for run in to protect the structure. Segments extend from a common base ring and are radially offset during run in. Alternating segments have landing surfaces on opposed ends such that on release of the structure the intervening segments land on such surfaces to form a cohesive single layer with all segments circumferentially aligned and against a surrounding tubular or the borehole wall. The structure is held retracted with a bi-directionally movable sleeve operable in a variety of ways from the surface. Internally the sleeve has splines to push the segments with the landing surfaces back so that the structure can collapse back into the sleeve for removal. Structures can be stacked and used as centralizers with alternating segments removed.

主权项

1. An apparatus for support or sealing around a mandrel in a cased or open hole borehole defined by a borehole wall, comprising:
a mandrel; at least one assembly of a plurality of segments extending from a base, said mandrel extending through said base; a retainer for selective retention of said segments adjacent said mandrel for run in and subsequently releasing said segments to move against the borehole wall for use, said retainer retracts said segments after said use for removal of said mandrel, base and segments from the borehole, said segments defining an open end opposite said base during use.