Patent ID: 8479809

Claim:
An antiextrusion backup system comprising: a first set of backup rings including an inner expandable backup ring having a first set of slots; and an outer expandable backup ring having a second set of slots, wherein the outer expandable back up ring is rotationally locked to the inner expandable backup ring to prevent an extrusion gap in an expanded condition of the backup rings; and, a second set of backup rings separated from the first set of backup rings by a deformable sealing element, wherein the first set of backup rings is adjacent a first axial end of the deformable sealing element and the second set of backup rings is adjacent a second axial end of the deformable sealing element when in an expanded condition of the first and second set of backup rings, the first and second sets of backup rings operable to prevent extrusion of the deformable sealing element therebetween when expanded, each of the first and second sets of backup rings having a first end and a second end, the first end of each of the first and second sets of backup rings having a larger diameter than the second ends thereof; wherein the second end of the second set of backup rings is located between the first end of the first set of backup rings and the first end of the second set of backup rings.