Resettable backup and system

Abstract

A backup comprising a gage ring having frustoconical surface and a groove in the frustoconical surface. The backup further includes a segment having a nose engaged with the groove, the segment having an element portion with an overlap finger and a finger receptor and a gage portion with an overlap finger and a finger receptor. A wedge ring is in contact with the segment and a retainer member is disposed to retain the segment. A method for using the backup and a system are included.

What is claimed is: 
     
         1 . A backup comprising:
 a gage ring having frustoconical surface and a groove in the frustoconical surface;   a segment having a nose engaged with the groove, the segment having an element portion with an overlap finger and a finger receptor and a gage portion with an overlap finger and a finger receptor;   a wedge ring in contact with the segment; and   a retainer member disposed to retain the segment.   
     
     
         2 . The backup as claimed in  claim 1  wherein the retainer member is a solid material is disposed about a longitudinal axis of the member. 
     
     
         3 . The backup as claimed in  claim 1  wherein the retainer member is a garter spring disposed about a longitudinal axis of the member. 
     
     
         4 . The backup as claimed in  claim 1  wherein the retainer member is a C-ring disposed about a longitudinal axis of the member. 
     
     
         5 . The backup as claimed in  claim 1  wherein the retainer member is a solid material helically wrapped around a longitudinal axis of the member. 
     
     
         6 . The backup as claimed in  claim 1  further comprising a hold down attached to the segment to retain the retainer member to the segment. 
     
     
         7 . The backup as claimed in  claim 6 , wherein the segment includes threaded holes to secure the hold down to the segment. 
     
     
         8 . The backup as claimed in  claim 1  wherein one or both of the element portion and gage portion overlap fingers includes a chamfer. 
     
     
         9 . The backup as claimed in  claim 1  further including hold down recesses in the segment. 
     
     
         10 . A downhole tool comprising:
 an element;   a first backup as claimed in  claim 1  adjacent the element.   
     
     
         11 . The downhole tool as claimed in  claim 10 , further comprising a second backup also adjacent the element and spaced from the first backup by the element. 
     
     
         12 . A method for managing a borehole system comprising:
 setting and unsetting the backup as claimed in  claim 1  a plurality of times.   
     
     
         13 . A borehole system comprising:
 a borehole in a subsurface formation;   a string disposed within the borehole;   a backup as claimed in  claim 1  disposed within or as a part of the string.   
     
     
         14 . A borehole system comprising:
 a borehole in a subsurface formation;   a string disposed within the borehole;   a tool as claimed in  claim 10  disposed within or as a part of the string.