Patent ID: 7963321
Filing Date: 2011-06-21
Classification: E21B

Abstract:
1. A swellable packer for positioning downhole in a well to seal with the interior surface of a borehole or an interior surface of a downhole tubular, comprising: a mandrel having a central axis and an exterior generally cylindrical surface; a swellable elastomeric sleeve-shaped body positioned over a portion of the exterior surface of the mandrel for swelling to seal between the mandrel and the interior surface of the borehole or the interior surface of the downhole tubular; a rigid end ring positioned over the exterior surface of the mandrel and axially secured to the mandrel; an elastomeric anti-extrusion member spaced axially between the swellable sleeve-shaped body and the rigid end ring, the elastomeric anti-extrusion member having a modulus of rigidity substantially greater than a modulus of rigidity of the swellable sleeve-shaped body, the elastomeric anti-extrusion member having a radial thickness adjacent the rigid end ring greater than a radial thickness of the elastomeric anti-extrusion member adjacent the swellable sleeve-shaped body; and a swellable elastomeric member spaced radially between the exterior surface of the mandrel and the elastomeric anti-extrusion member adjacent the swellable sleeve-shaped body.