Tubing Pressure Actuated Safety Valve

Abstract

A tubular isolation system is operably connected with a movable member that selectively enables or disables the isolation system at least one time. In an embodiment the movable member is actuated by flow or pressure against a spring bias with an indexing system to regulate movable member movement so that that two opposed positions are attainable. The movable member can be a sleeve with a flow passage therethrough. One way to shift the sleeve is to land a ball on a seat on top of the sleeve and apply a cycle of pressure against the bias so that a j-slot moves the sleeve between end positions. The safety device is dual flappers in one embodiment. The sleeve can also be moved with circulation flow through the tubing with returns coming up the annulus. Alternatively a restriction can be used that later disappears for production.

We claim: 
     
         1 . A borehole safety assembly, comprising:
 at least one closure member to selectively close a passage in a tubular string in the borehole;   a movable member actuated with pressure or flow in said passage to selectively disable said closure member from closing said passage with a first movement from a first position to a second position and to subsequently enable said closure member to close said passage with a second movement from a second position back toward said first position.   
     
     
         2 . The assembly of  claim 1 , wherein:
 said movable member comprises a sleeve having a passage therethrough.   
     
     
         3 . The assembly of  claim 2 , wherein:
 said passage is selectively blocked with an object to move said sleeve with pressure on said object.   
     
     
         4 . The assembly of  claim 3 , wherein:
 said sleeve is operably connected to an indexing feature responsive to application and removal of pressure on said object.   
     
     
         5 . The assembly of  claim 4 , wherein: 
       said sleeve is biased against applied pressure on said object. 
     
     
         6 . The assembly of  claim 4 , wherein: 
       said indexing feature selectively retains said sleeve in a first and a second position. 
     
     
         7 . The assembly of  claim 6 , wherein: 
       said sleeve spaced apart from said closure member in said first position. 
     
     
         8 . The assembly of  claim 7 , wherein: 
       said closure member comprises at least one flapper and said sleeve engaging and moving past said at least one flapper in said second position. 
     
     
         9 . The assembly of  claim 8 , wherein: 
       said sleeve comprising spaced seals that isolate said at least one flapper from well fluids in said second position with said at least one flapper located between said sleeve and a surrounding mandrel. 
     
     
         10 . The assembly of  claim 1 , wherein:
 said closure member comprises at least one flapper and said movable member comprising a sleeve;   said sleeve spaced from said flapper in a first position and engaging and moving past said at least one flapper in a second position;   said sleeve comprising spaced seals that isolate said at least one flapper from well fluids in said second position with said at least one flapper located between said sleeve and a surrounding mandrel.   
     
     
         11 . The assembly of  claim 9 , wherein:
 said sleeve selectively movable from said first to said second and back to said first position using said indexing feature.   
     
     
         12 . The assembly of  claim 10 , wherein:
 said sleeve selectively movable from said first to said second and back to said first position.   
     
     
         13 . A borehole safety assembly, comprising:
 at least one flapper to selectively close a passage in a mandrel;   a selectively movable sleeve responsive to flow or pressure in said passage to remain spaced apart from said flapper in a first position and to hold said at least one flapper in an open position in a second position of said sleeve.   
     
     
         14 . The assembly of  claim 13 , wherein:
 said sleeve comprising a passage that is selectively blocked with an object to move said sleeve with pressure on said object.   
     
     
         15 . The assembly of  claim 14 , wherein:
 said sleeve is operably connected to an indexing feature responsive to application and removal of pressure on said object.   
     
     
         16 . The assembly of  claim 15 , wherein: 
       said sleeve is biased against applied pressure on said object. 
     
     
         17 . The assembly of  claim 15 , wherein:
 said indexing feature selectively retains said sleeve in a first and a second position.   
     
     
         18 . The assembly of  claim 15 , wherein:
 said sleeve comprising spaced seals that isolate said at least one flapper from well fluids in said second position with said at least one flapper located between said sleeve and said mandrel.   
     
     
         19 . The assembly of  claim 13 , wherein:
 said sleeve comprising spaced seals that isolate said at least one flapper from well fluids in said second position with said at least one flapper located between said sleeve and said mandrel.   
     
     
         20 . The assembly of  claim 13 , wherein:
 said at least one flapper comprises multiple flappers oriented to prevent flow uphole to a surface location when said sleeve is in said first position.   
     
     
         21 . A borehole completion method, comprising:
 milling out at least one plug with a mill attached to a tubular string;   providing at least one closure mounted in said string;   releasing said mill from the string;   relying on said at least one closure as a safety device for the string after releasing the mill;   supporting the string in the borehole for use in production;   retaining said at least one closure in an open position with applied flow or pressure in the string to permit fluid movement between a surface location and a formation.   
     
     
         22 . The method of  claim 21 , comprising:
 defeating said closure with a sleeve having a passage therethrough;   moving said sleeve with pressure on an object landed on a seat on said sleeve.   
     
     
         23 . The method of  claim 22 , comprising:
 indexing said sleeve between two positions where said closure is enabled and disabled with applied pressure cycles.   
     
     
         24 . The method of  claim 23 , comprising:
 using at least one flapper for said closure;   providing spaced seals on said sleeve;   maintaining said at least one flapper between said sleeve and said tubular string between said spaced seals to isolate said at least one flapper from fluids in the string.