Patent ID: 9528341
Filing Date: 2016-12-27
CPC Classification: E21B

Claim Text:
1. A retrievable apparatus for forming a seal against a borehole wall, comprising: a mandrel; a sealing assembly on said mandrel operable between a run in and a set position for sealing against the borehole wall and release from the borehole wall; an anti-extrusion assembly on said mandrel operable between a run in and a set position, said anti-extrusion assembly storing potential energy force in said set position that acts in a direction to move said anti-extrusion assembly toward said run in position when said force is released; said anti-extrusion assembly having a larger initial internal diameter at a first end closer to said sealing assembly than a second internal diameter located adjacent an opposite end thereof said second internal diameter defined by, opposed surfaces clamped toward each other with a clamp for guided opposed axial relative movement with respect to said mandrel.