Method and apparatus for operating a shifting tool

Abstract

The disclosure pertains to engaging a longitudinally slidable sleeve within a well. The apparatus comprises a tool string slidably locatable within said well and a shifting tool slidably locatable within said sleeve at an end of a tool string. The shifting tool has a central bore therethrough and keys operable to be extended therefrom. The apparatus further includes a reservoir in fluidic communication with said central bore of said shifting tool and being operable to contain and hold a quantity of a fluid at a predetermined pressure sufficient to actuate said shifting tool. The method comprises comprises pressurizing the reservoir, reducing said pressure in said tool string above said reservoir slidably displacing said shifting tool and sleeve valve within said well by displacing said tool string therein.

What is claimed is: 
     
         1 . An apparatus for selectably engaging a longitudinally slidable sleeve within a well comprising:
 a tool string slidably locatable within said well;   a shifting tool slidably locatable within said sleeve at an end of a tool string said shifting tool having a central bore therethrough and keys operable to be extended from an outer surface of said shifting tool when said central bore is supplied with said fluid above a predetermined pressure, said keys being engagable upon said sleeve so as to permit said shifting tool to move said sleeve longitudinally within said tubular body;   a reservoir in fluidic communication with said central bore of said shifting tool and being operable to contain and hold a quantity of a fluid at a predetermined pressure sufficient to actuate said shifting tool.   
     
     
         2 . The apparatus of  claim 1  further comprising an isolation body adapted to retain said fluid in said reservoir after said pressure has been reduced in said tool string. 
     
     
         3 . The apparatus of  claim 2  wherein said isolation body comprises a check valve adapted to permit a flow of fluid into said reservoir in a downward direction only. 
     
     
         4 . The apparatus of  claim 3  wherein said check valve is located above said shifting tool. 
     
     
         5 . The apparatus of  claim 1  wherein said reservoir is formed between an inner mandrel and an outer housing of said tool string. 
     
     
         6 . The apparatus of  claim 5  wherein said inner mandrel and outer housing are longitudinally movable relative to each other along said tool string. 
     
     
         7 . The apparatus of  claim 6  wherein said outer housing is operably connected to said tool and wherein said inner mandrel is operably connected to a pipe extending to a ground level of said well. 
     
     
         8 . The apparatus of  claim 7  wherein said reservoir is formed between an end wall and a lead protrusion extending radially outward from said inner mandrel. 
     
     
         9 . The apparatus of  claim 8  wherein said end wall slidably seal against said outer housing. 
     
     
         10 . The apparatus of  claim 8  wherein said outer housing includes a bypass protrusion extending radially inwardly therefrom at a position adapted to seal against said lead protrusion of said inner mandrel when said inner mandrel and outer housing are at a first position relative to each other. 
     
     
         11 . The apparatus of  claim 10  wherein said bypass protrusion is adapted to longitudinally disengage from said lead protrusion as said inner mandrel is slidably displaced relative to said outer housing so as to compress said reservoir. 
     
     
         12 . The apparatus of  claim 10  wherein said bypass protrusion includes a bleed passage therethrough sized to permit a predetermined flow rate of fluid therethrough. 
     
     
         13 . A method for selectably engaging a longitudinally slidable sleeve within a well comprising:
 providing a tool string slidably locatable within said well;   providing a shifting tool slidably locatable within said sleeve at an end of a tool string said shifting tool having a central bore therethrough and keys operable to be extended from an outer surface of said shifting tool when said central bore is supplied with said fluid above a predetermined pressure, said keys being engagable upon said sleeve so as to permit said shifting tool to move said sleeve longitudinally within said tubular body; and   providing a reservoir in fluidic communication with said central bore of said shifting tool and being operable to contain and hold a quantity of a fluid at a predetermined pressure sufficient to actuate said shifting tool.   
     
     
         14 . A method for selectably engaging a longitudinally slidable sleeve within a well comprising:
 locating a tool string having a shifting tool therein within said well, wherein said shifting tool has a central bore therethrough and keys operable to be extended from an outer surface of said shifting tool when said central bore is supplied with said fluid above a predetermined pressure, said keys being engagable upon said sleeve so as to permit said shifting tool to move said sleeve longitudinally within said tubular body;   pressurizing a reservoir in fluidic communication with said central bore of said shifting tool and being operable to contain and hold a quantity of a fluid at a predetermined pressure sufficient to actuate said shifting tool to extend said keys from said outer surface of said shifting tool into engagement with a sleeve valve;   reducing said pressure in said tool string above said reservoir; and   slidably displacing said shifting tool and sleeve valve within said well by displacing said tool string therein.