Hydraulic Three Position Stroker Tool

Abstract

A stroker tool operates a subterranean tool between three operating positions. The stroker tool includes an outer housing defining a piston chamber within. A piston assembly having first and second piston members is moveable within the piston chamber between a first position, a second position, and a third position. A shifting member is operably connected with the piston assembly and is moved to an uppermost axial position when the piston assembly is in the first position, an intermediate axial position when the piston assembly is in the second position, and a lowermost axial position when the piston assembly is in the third position.

What is claimed is: 
     
         1 . A stroker tool for operating a subterranean tool between three operating positions, the stroker tool comprising:
 an outer housing defining a piston chamber within;   a piston assembly that is moveable within the piston chamber between a first configuration, a second configuration, and a third configuration; and   a shifting member operably connected with the piston assembly that is moved to an uppermost axial position when the piston assembly is in the first configuration, an intermediate axial position when the piston assembly is in the second configuration, and a lowermost axial position when the piston assembly is in the third configuration.   
     
     
         2 . The stroker tool of  claim 1  wherein the piston assembly comprises:
 a first piston member that is axially moveable within the piston chamber between upper and lower positions; and 
 a second piston member that is axially moveable within the piston chamber between upper, lower and intermediate positions, the shifting member being affixed to the second piston member. 
 
     
     
         3 . The stroker tool of  claim 1  wherein the piston chamber includes:
 a first chamber portion; and 
 a second chamber portion, the first chamber portion having a larger diameter than the second chamber portion. 
 
     
     
         4 . The stroker tool of  claim 2  further comprising a plurality of fluid flow lines associated with the outer housing to selectively flow fluid into and out of the piston chamber to move the piston assembly between the first, second and third configurations. 
     
     
         5 . The stroker tool of  claim 4  wherein there are three fluid flow lines. 
     
     
         6 . The stroker tool of  claim 1  wherein the subterranean tool comprises a sliding sleeve valve. 
     
     
         7 . A stroker tool for operating a subterranean tool between three operating positions, the stroker tool comprising:
 an outer housing defining a piston chamber within;   a piston assembly that is moveable within the piston chamber between a first configuration, a second configuration, and a third configuration, the piston assembly having a first piston member and a second piston member; and   a shifting member operably connected with the piston assembly that is moved to an uppermost axial position when the piston assembly is in the first configuration, an intermediate axial position when the piston assembly is in the second configuration, and a lowermost axial position when the piston assembly is in the third configuration.   
     
     
         8 . The stroker tool of  claim 7  wherein the piston chamber includes:
 a first chamber portion; and 
 a second chamber portion, the first chamber portion having a larger diameter than the second chamber portion. 
 
     
     
         9 . The stroker tool of  claim 7  further comprising a plurality of fluid flow lines associated with the outer housing to selectively flow fluid into and out of the piston chamber to move the piston assembly between the first, second and third configurations. 
     
     
         10 . The stroker tool of  claim 9  wherein there are three fluid flow lines. 
     
     
         11 . The stroker tool of  claim 7  wherein the subterranean tool comprises a sliding sleeve valve. 
     
     
         12 . The stroker tool of  claim 7  wherein:
 the first piston member is axially moveable within the piston chamber between upper and lower positions; and 
 the second piston member is axially moveable within the piston chamber between upper, lower and intermediate positions, the shifting member being affixed to the second piston member. 
 
     
     
         13 . A method of actuating a subterranean tool comprising the steps of:
 associating a shifting tool of a stroker tool with a subterranean tool that is moveable between three positions; and   selectively moving a piston assembly within the stroker tool between first, second and third configurations to cause the shifting tool to move the subterranean tool between its first, second and third positions.   
     
     
         14 . The method of  claim 13  wherein the step of selectively moving a piston assembly within the stroker tool further comprises selectively injecting hydraulic fluid into the piston chamber. 
     
     
         15 . The method of  claim 13  wherein the step of selectively moving a piston assembly within the stroker tool further comprises moving a first piston member and a second piston member within the piston chamber. 
     
     
         16 . The method of  claim 13  wherein:
 the subterranean tool is a sliding sleeve valve; 
 the first position corresponds to a fully open position for the sliding sleeve valve; 
 the second position corresponds to a partially open position for the sliding sleeve valve; and 
 the third position corresponds to a fully closed position for the sliding sleeve valve.