Patent ID: 9228411
Filing Date: 2016-01-05
CPC Classification: E21B

Claim Text:
1. A wellbore packer back-up ring assembly for limiting the extrusion of a packing element in a packer comprising; a first back-up ring adapted to be positioned about a mandrel at a first end of the packing element; and a second back-up ring adapted to be positioned about the mandrel spaced from the first back-up ring and at a second end of the packing element; wherein the first back-up ring and the second back-up ring each include an inner facing annular surface and an outer facing annular surface defining an outer diameter across the back-up ring and including a gripping structure for biting into a constraining surface in a well and the first back-up ring and the second back-up ring each are expandable to increase the outer diameter and to expand radially outwardly from the mandrel, wherein the first back-up ring is formed of a first material and the gripping structure includes teeth having a hardness greater than the first material.