Seal Bore for High Expansion Bridge Plugs

Abstract

One or more pup joints are provided in a tubular string at one or more predetermined locations. The seal bores are recessed to protect them from passing tool until needed as a sealing location for a packer or bridge plug having a metal-to-metal seal that is radially extended into sealing contact with the seal bore surface. The seal surface can be recessed to protect it from passing tools. A coating or sleeve can be fit to the sealing surface that is penetrated by the sealing element of the packer or bridge plug for the metal to metal seal. The presence of the protective sleeve can also enhance the metal to metal seal by abutting the sealing element on opposed sides after the sealing element penetrates through the sleeve.

1 . A method of subterranean zonal isolation, comprising:
 providing at least one seal bore assembly of a predetermined diameter in a tubular string;   running in at least one barrier having an extendable seal to said seal bore assembly;   actuating said metal seal into metal to metal sealing contact with said seal bore assembly.   
     
     
         2 . The method of  claim 1 , comprising:
 providing a sealing surface having said predetermined diameter on said seal bore assembly;   positioning at least one end portion adjacent said sealing surface with a smaller diameter than said sealing surface.   
     
     
         3 . The method of  claim 1 , comprising:
 providing a sealing surface having said predetermined diameter on said seal bore assembly;   covering said sealing surface with a cover.   
     
     
         4 . The method of  claim 3 , comprising:
 making said extendable seal metallic;   penetrating said cover while extending said metal seal.   
     
     
         5 . The method of  claim 4 , comprising:
 using said cover to aid the seal formed by said metal seal.   
     
     
         6 . The method of  claim 4 , comprising:
 penetrating said sealing surface with said metal seal.   
     
     
         7 . The method of  claim 3 , comprising:
 making said extendable seal metallic;   removing said cover before actuating said metal seal.   
     
     
         8 . The method of  claim 2 , comprising:
 positioning two end portions on opposed sides of said sealing surface so as to recess said sealing surface with respect to said end portions.   
     
     
         9 . The method of  claim 1 , comprising:
 making said extendable seal metallic;   providing a locating device on said seal bore assembly to engage said barrier for locating said metal seal with respect to said seal bore assembly.   
     
     
         10 . The method of  claim 1 , comprising:
 fully covering said sealing surface with said cover.   
     
     
         11 . The method of  claim 10 , comprising:
 building said cover onto said sealing surface or forming said cover into a sleeve and inserting said sleeve against said sealing surface.   
     
     
         12 . The method of  claim 9 , comprising:
 providing discretely shaped locating devices on different seal bore assemblies on said tubular string;   matching a mating device on said barrier so that it locates at a single predetermined location.   
     
     
         13 . The method of  claim 1 , comprising:
 providing a plurality of spaced seal bore assemblies on said string;   locating said at least one barrier on at least one predetermined seal bore assembly.   
     
     
         14 . The method of  claim 1 , comprising:
 making said extendable seal metallic;   configuring said metallic seal to specifically engage the predetermined dimension of said sealing surface as opposed to the variations of inside diameter of said string size taking into account the variety of wall thickness sizes that could be used for said string.   
     
     
         15 . In combination at least one barrier for a metallic tubular string having an extendable seal and at least one seal bore as a component of said string against which said extendable seal selectively engages for a seal. 
     
     
         16 . The combination of  claim 15 , wherein:
 said seal bore comprises a joint in said string and a recessed sealing surface between ends of said joint.   
     
     
         17 . The combination of  claim 15 , wherein:
 said seal bore comprises a joint in said string and a sealing surface that is covered.   
     
     
         18 . The combination of  claim 17 , wherein:
 said seal is metallic and penetrates said cover when extended.   
     
     
         19 . The combination of  claim 18 , wherein:
 said extendable metallic seal penetrates said sealing surface.   
     
     
         20 . The combination of  claim 18 , wherein:
 said penetrated cover cooperates for sealing with said extendable metal seal.   
     
     
         21 . The combination of  claim 15 , wherein:
 said seal bore comprises a joint in said string and a sealing surface of a predetermined diameter;   said extendable seal is metallic and configured to sealingly extend specifically for sealing against that predetermined sealing surface diameter instead of a variation of internal tubular diameters possible for a string of a given size taking into account the variation in wall thickness for different weights per foot.   
     
     
         22 . The combination of  claim 17 , wherein:
 said sealing surface is fully covered by a sleeve or by a cover built on said sealing surface.