Casing Fill and Circulation Tool with Metal Seal Featurel

Abstract

A fill up and circulating tool has a threaded hub covered by a rapidly removable cover. The cover protects the threads from damage until a well kick occurs. When the well kicks the cover is rapidly removed and the fill up tool is brought down with the top drive to which it is connected. The top drive rotates the mandrel of the tool to make the threads up to a coupling on the uppermost stand of casing to provide a metal to metal seal that can resist a well kick coming up through the casing and around the outside of the fill up tool. The top drive system has a surface valve that can be closed quickly to contain the kick through the fill up tool.

We claim: 
     
         1 . A fill and circulation tool assembly for running a tubular string to a subterranean location, comprising:
 a mandrel having a passage therethrough and an end connection for support for selective placement in the tubular string;   a metal seal mounted to said mandrel for selective actuation against an interior wall of the tubular string to retain a pressure surge from the subterranean location.   
     
     
         2 . The assembly of  claim 1 , further comprising:
 a resilient seal mounted to said mandrel for retention of pressure of fluid pumped through said passage when circulating fluid through said tubular string.   
     
     
         3 . The assembly of  claim 1 , wherein:
 said metal seal comprises a threaded bushing mounted to said mandrel.   
     
     
         4 . The assembly of  claim 3 , further comprising:
 a threaded coupling on the tubular string to accept said bushing.   
     
     
         5 . The assembly of  claim 1 , wherein:
 said metal seal comprises a threaded coupling mounted to said mandrel.   
     
     
         6 . The assembly of  claim 5 , further comprising:
 a threaded end on the tubular string to accept said coupling.   
     
     
         7 . The assembly of  claim 1 , wherein:
 said metal seal is axially compressed to extend radially into contact with an inner wall of the tubular string.   
     
     
         8 . The assembly of  claim 7 , wherein:
 said metal seal is mechanically or hydraulically actuated.   
     
     
         9 . The assembly of  claim 7 , wherein:
 said metal seal comprises a bellows.   
     
     
         10 . The assembly of  claim 7 , wherein:
 said metal seal comprises at least two surfaces defining at least one ridge that moves radially into contact with the tubular string.   
     
     
         11 . The assembly of  claim 1 , wherein:
 said metal seal further comprises a removable cover.   
     
     
         12 . The assembly of  claim 11 , wherein:
 said cover overlays an outer surface of said metal seal to protect said outer surface from damage during normal running and circulating the tubing string.   
     
     
         13 . The assembly of  claim 11 , wherein:
 removal of said cover allows said metal seal to enter the tubular string.   
     
     
         14 . The assembly of  claim 1 , wherein:
 said metal seal is actuated without mandrel removal from the tubular string.   
     
     
         15 . The assembly of  claim 1 , wherein:
 said mandrel is selectively moved axially and rotated by a top drive.