System and Method for Retrieving a Well Tool from a Wellbore

Abstract

A technique utilizes a fishing tool and method for retrieving a fish from a downhole location without removal of a downhole completion. The fishing tool comprises a housing and a piston slidably mounted in the housing. Grip legs are engaged with the piston such that movement of the piston in a first direction along the housing moves the grip legs to a disengaged position for receiving the fish. Subsequent movement of the piston in a second direction causes the plurality of grip legs to move to an engaged position with the fish. The grip legs can be moved between the disengaged and engaged positions after the fishing tool is moved through the completion.

1 . A device for use in a well, comprising:
 a fishing tool to engage a fish in a wellbore, the fishing tool comprising:
 a housing; 
 a piston slidably mounted in the housing; 
 a plurality of grip legs engaged with the piston, wherein movement of the piston in a first direction along the housing causes the plurality of grip legs to move to a disengaged position for receiving the fish and movement of the piston in a second direction causes the plurality of grip legs to move to an engaged position. 
   
   
   
       2 . The device as recited in  claim 1 , wherein the piston is spring biased to move the plurality of grip legs to the engaged position. 
   
   
       3 . The device as recited in  claim 2 , wherein the piston comprises a fluid flow passage through which fluids can be flowed axially through the piston. 
   
   
       4 . The device as recited in  claim 3 , wherein the piston comprises a variable size port positioned in the fluid flow passage to allow a desired flow rate through the piston. 
   
   
       5 . The device as recited in  claim 1 , wherein each grip leg of the plurality of grip legs comprises a connection end pivotably connected to the piston. 
   
   
       6 . The device as recited in  claim 5 , wherein each grip leg is spring biased to pivot the grip leg toward the disengaged position. 
   
   
       7 . The device as recited in  claim 6 , wherein movement of the connection end of each grip leg into the housing forces the grip leg toward the engaged position. 
   
   
       8 . The device as recited in  claim 1 , wherein each grip leg of the plurality of grip legs comprises a plurality of teeth oriented to hold the fish when the plurality of grip legs are in the engaged position. 
   
   
       9 . A method of forming a fishing tool, comprising:
 slidably mounting a piston within a housing sized to move through a completion within a wellbore;   providing the piston with a pressure end against which fluid pressure is applied to move the piston within the housing;   pivotably connecting a plurality of grip legs to the piston in a manner that allows the grip legs to pivot between an outward position and an inward position as the piston is moved through the housing.   
   
   
       10 . The method as recited in  claim 9 , further comprising biasing the plurality of grip legs toward the outward position. 
   
   
       11 . The method as recited in  claim 10 , wherein biasing comprises spring biasing. 
   
   
       12 . The method as recited in  claim 9 , further comprising biasing the piston in a direction that would move the grip legs to the inward position. 
   
   
       13 . The method as recited in  claim 12 , wherein biasing comprises spring biasing. 
   
   
       14 . The method as recited in  claim 9 , further comprising forming an axial flow passage through the piston to enable a desired amount of fluid flow through the fishing tool. 
   
   
       15 . The method as recited in  claim 9 , further comprising using the housing to force the plurality of grip legs to the inward position when the piston is moved in the appropriate direction. 
   
   
       16 . A method of fishing for a tool in a wellbore, comprising:
 moving a fishing tool downhole through a completion in the wellbore;   applying sufficient pressure against a piston of the fishing tool to cause a plurality of grip legs to move to a disengaged position;   placing the plurality of grip legs in a position to engage a fish within the wellbore; and   causing the piston to move in an opposite direction and pivot the plurality of grip legs into engagement with the fish to allow retrieval of the fish through the completion.   
   
   
       17 . The method as recited in  claim 16 , wherein moving comprises moving the fishing tool downhole on coiled tubing. 
   
   
       18 . The method as recited in  claim 16 , further comprising pumping fluid through the fishing tool to clear debris from inside the fishing tool. 
   
   
       19 . The method as recited in  claim 16 , wherein applying sufficient pressure comprises pivoting the plurality of grip legs outwardly until the plurality of grip legs contacts a surrounding casing. 
   
   
       20 . The method as recited in  claim 16 , further comprising spring biasing the plurality of grip legs toward the disengaged position. 
   
   
       21 . The method as recited in  claim 16 , wherein causing comprises gripping the fish with a plurality of teeth disposed on each grip leg of the plurality of grip legs. 
   
   
       22 . A system for fishing in a wellbore, comprising:
 a coiled tubing string; and   a fishing tool assembly mounted to the coiled tubing string, the fishing tool assembly comprising a fishing tool having:
 a housing; 
 a piston slidable within the housing; and 
 a plurality of movable grip legs that cooperate with the piston such that movement of the piston enables movement of the plurality of movable grip legs between engaged and disengaged positions. 
   
   
   
       23 . The system as recited in  claim 22 , wherein the plurality of movable grip legs are pivotably mounted to the piston. 
   
   
       24 . The system as recited in  claim 23 , wherein the housing is positioned to force the plurality of movable grip legs to the engaged position upon movement of the piston in a first direction. 
   
   
       25 . The system as recited in  claim 24 , wherein the plurality of movable grip legs are biased toward the disengaged position, such that movement of the piston in a second direction enables movement of the plurality of movable grip legs to the disengaged position.