Fishing overshot tool

Abstract

A fishing tool gripper head including at least one moveable jaw of a set of jaws, a motivator including one or more of an SMA, SMP, or EAP material in operable communication with the at least one moveable jaw and a method for engaging a fish in a wellbore.

1 . A fishing tool gripper head comprising:
 at least one movable jaw of a set of jaws;   a motivator including one or more of an SMA, SMP or EAP material in operable communication with the at least one movable jaw.   
   
   
       2 . The gripper head as claimed in  claim 1  wherein the motivator is a wire. 
   
   
       3 . The gripper head as claimed in  claim 1  wherein the wire is helically wrapped around the set of jaws. 
   
   
       4 . The gripper head as claimed in  claim 1  wherein the motivator is a band. 
   
   
       5 . The gripper head as claimed in  claim 1  wherein the band is wrapped around the set of jaws. 
   
   
       6 . The gripper head as claimed in  claim 1  wherein the motivator is a directly displacing motivator. 
   
   
       7 . The gripper head as claimed in  claim 1  wherein jaws other than the at least one movable jaw of the set of jaws are immobile. 
   
   
       8 . A method for engaging a fish in a wellbore comprising:
 running a fishing tool with an adjustable gripper head;   facilitating a threshold condition at the gripper head to cause a change in the dimension of the gripper head;   engaging a fish.   
   
   
       9 . The method as claimed in  claim 8  wherein the threshold condition is at least one of temperature and electrical input. 
   
   
       10 . The method as claimed in  claim 8  further comprising pulling the fish out of the wellbore.