Fishing tool with electric release

Abstract

A fishing tool ( 1 ) configured to retrieve a fish ( 100 ) from a wellbore, having a fish engagement arrangement ( 3 ) with fish engagement means ( 5 ) configured to lock the fishing tool to the fish inside a well. The fishing tool ( 1 ) has an electrically actuated fish disengagement arrangement ( 4 ), which is configured to unlock the fishing tool from the fish, wherein the fish disengagement arrangement ( 4 ) comprises an electric actuator ( 13 ). The fish disengagement arrangement ( 4 ) comprises a direct mechanical force link ( 6 ) between the electric actuator ( 13 ) and the fish engagement means ( 5 ), wherein the direct mechanical force link is configured to connect a mechanical force from the electric actuator ( 13 ) to the fish engagement means ( 5 ).

The invention claimed is: 
     
         1 . A fishing tool configured to retrieve a fish from a wellbore, the fishing tool comprising:
 a fish engagement arrangement with fish engagement means configured to lock the fishing tool to the fish inside the wellbore;   wherein the fishing tool further comprises an electrically actuated fish disengagement arrangement, which is configured to unlock the fishing tool from the fish;   wherein the electrically actuated fish disengagement arrangement comprises an electric actuator;   wherein the electrically actuated fish disengagement arrangement comprises a direct mechanical force link between the electric actuator and the fish engagement means; and   wherein the direct mechanical force link is configured to connect a mechanical force from the electric actuator to the fish engagement means;   wherein the fish engagement arrangement comprises:
 a cone that is axially fixed with respect to a tool housing; and 
 a plurality of latching dogs configured to slide against the cone when moved axially with respect to the tool housing; and 
   wherein the fish disengagement arrangement is configured to move the latching dogs with respect to the cone upon actuation.   
     
     
         2 . The fishing tool according to  claim 1 , wherein the direct mechanical force link comprises a rotation to linear converter and the electric actuator is an electric rotary motor, which is connected to the rotation to linear converter. 
     
     
         3 . The fishing tool according to  claim 1 , wherein the fishing tool comprises an electric battery and a control unit, wherein the control unit is programmed to perform repeated disconnection attempts, by operating the electric actuator, in a situation where a first disconnection attempt is unsuccessful. 
     
     
         4 . The fishing tool according to  claim 3 , wherein the control unit is programmed to increase an output force from the electric actuator in succeeding disconnection attempts. 
     
     
         5 . A method of retrieving the fishing tool according to  claim 1  from a downhole position in a subterranean well, wherein the fishing tool is locked to the fish in the wellbore, the method comprising:
 a) providing electric power to the electric actuator in the fishing tool, thereby actuating the electrically actuated fish disengagement arrangement and disengaging the fishing tool from the fish, by transferring a mechanical disconnecting force from the electric actuator to the fish engagement means over the direct mechanical force link arranged between the electric actuator and the fish engagement means. 
 
     
     
         6 . The method according to  claim 5 , wherein step a) comprises providing electric power to an electric rotary motor and providing a linear movement of a member of the fish disengagement arrangement. 
     
     
         7 . The method according to  claim 5 , wherein step a) comprises programming a control unit to provide electric power from a battery in the fishing tool to the electrically actuated fish disengagement arrangement after a predetermined time. 
     
     
         8 . The method according to  claim 5 , wherein step a) comprises providing an electric signal from a surface to the electric actuator through an electric line. 
     
     
         9 . A fishing tool configured to retrieve a fish from a wellbore, the fishing tool comprising:
 a fish engagement arrangement with fish engagement means configured to lock the fishing tool to the fish inside the wellbore;   wherein the fishing tool further comprises an electrically actuated fish disengagement arrangement, which is configured to unlock the fishing tool from the fish;   wherein the electrically actuated fish disengagement arrangement comprises an electric actuator;   wherein the electrically actuated fish disengagement arrangement comprises a direct mechanical force link between the electric actuator and the fish engagement means; and   wherein the direct mechanical force link is configured to connect a mechanical force from the electric actuator to the fish engagement means;   wherein the fishing tool further comprises a mechanical disconnection arrangement; and   wherein:
 the fish engagement arrangement comprises a cone that is axially fixed with respect to a tool housing; and 
 the mechanical disconnection arrangement comprises one or more shear pins, configured to pull latching dogs off their engagement with the cone when the shear pins are in a shorn off state. 
   
     
     
       10. The fishing tool according to  claim 1 , wherein the latching dogs are configured to engage with 1) an external face or profile of the fish or 2) an internal face, profile or bore of the fish.  
     
     
       11. The fishing tool according to  claim 1 , wherein:
 the latching dogs are repeatedly and selectively movable in an axial sense relative to the cone between a wedged position and a non-wedged position.    
     
     
       12. The fishing tool according to  claim 11 , wherein the cone is configured to force the latching dogs to move radially when the latching dogs axially slide against the cone.  
     
     
       13. The fishing tool according to  claim 11 , wherein:
 in the wedged position, the cone is configured to wedge the latching dogs against the fish, and   in the non-wedged position, the latching dogs are radially and/or axially spaced away from the cone, so as to allow disengagement the fishing tool from the fish.    
     
     
       14. The fishing tool according to  claim 11 , wherein:
 the cone is configured to force the latching dogs to move radially in a first radial direction when the latching dogs axially slide against the cone,   in the wedged position, the cone is configured to substantially restrain the latching dogs against radial movement in a second radial direction, opposite the first radial direction, and   in the non-wedged position, the latching dogs are configured to be allowed to move radially in the first radial direction or the second radial direction.    
     
     
       15. The fishing tool according to  claim 1 , wherein the latching dogs are configured to engage with an external face or profile of the fish, and the latching dogs are positioned radially inwards of the cone.  
     
     
       16. The fishing tool according to  claim 1 , wherein the latching dogs are configured to engage with an internal face, bore or profile of the fish, and the latching dogs are positioned radially outwards of the cone.  
     
     
       17. A fishing tool configured to retrieve a fish from a wellbore, the fishing tool comprising:
 a tool housing;   a fish engagement arrangement including a cone, and a plurality of latching dogs configured to slide against the cone when moved axially with respect to the tool housing, the latching dogs being configured to lock the fishing tool to the fish inside the wellbore; and   an electric actuator configured to selectively initiate axial movement of the latching dogs relative to the cone to allow the latching dogs to separate from the cone and to allow the fishing tool to unlock from the fish, the latching dogs being configured to move radially when sliding against the cone and when being separated from the cone.    
     
     
       18. The fishing tool according to  claim 17 , wherein the latching dogs are configured to engage with 1) an external face or profile of the fish or 2) an internal face, profile or bore of the fish.  
     
     
       19. The fishing tool according to  claim 17 , wherein:
 each of the latching dogs is located at end of a respective latching finger; and   the latching dogs are repeatedly and selectively movable in an axial sense relative to the cone between a wedged position and a non-wedged position.    
     
     
       20. The fishing tool according to  claim 19 , wherein the cone is configured to force the latching dogs to move radially when the latching dogs axially slide against the cone.  
     
     
       21. The fishing tool according to  claim 19 , wherein:
 in the wedged position, the cone is configured to wedge the latching dogs against the fish, and   in the non-wedged position, the latching dogs are radially and/or axially spaced away from the cone, so as to allow disengagement the fishing tool from the fish.    
     
     
       22. The fishing tool according to  claim 19 , wherein:
 the cone is configured to force the latching dogs to move radially in a first radial direction when the latching dogs axially slide against the cone,   in the wedged position, the cone is configured to substantially restrain the latching dogs against radial movement in a second radial direction, opposite the first radial direction, and   in the non-wedged position, the latching dogs are configured to be allowed to move radially in the first radial direction or the second radial direction.    
     
     
       23. The fishing tool according to  claim 17 , wherein the latching dogs are configured to engage with an external face or profile of the fish, and the latching dogs are positioned radially inwards of the cone.  
     
     
       24. The fishing tool according to  claim 23 , wherein the fish includes the external profile provided on the external face of the fish, and each of the dogs includes a rear shoulder configured to engage the external profile of the fish.  
     
     
       25. The fishing tool according to  claim 24 , wherein the cone is configured to be positioned radially outward of the external face and profile of the fish.  
     
     
       26. The fishing tool according to  claim 17 , wherein the latching dogs are configured to engage with an internal face, bore or profile of the fish, and the latching dogs are positioned radially outwards of the cone.  
     
     
       27. The fishing tool according to  claim 26 , wherein the fish includes the internal profile provided in the bore, and each of the dogs includes a rear shoulder configured to engage the internal profile.  
     
     
       28. The fishing tool according to  claim 18 , wherein the cone is configured to enter inside of the bore of the fish.  
     
     
       29. A fishing tool configured to retrieve a fish from a wellbore, the fishing tool comprising:
 a fish engagement arrangement including a plurality of latching dogs configured to lock the fishing tool to the fish inside the wellbore,   an electrically actuated fish disengagement arrangement configured to unlock the fishing tool from the fish, wherein the electrically actuated fish disengagement arrangement comprises an electric actuator and a mechanical force link between the electric actuator and the latching dogs; and   wherein the mechanical force link is configured to connect a mechanical force from the electric actuator to the latching dogs,   wherein the fish engagement arrangement comprises:
 a cone that is axially fixed with respect to a tool housing; 
 wherein the latching dogs are configured to slide against the cone when moved axially with respect to the tool housing; and 
   wherein the fish disengagement arrangement is configured to move the latching dogs with respect to the cone upon actuation.    
     
     
       30. The fishing tool according to  claim 29 , wherein the latching dogs are configured to engage with 1) an external face or profile of the fish or 2) an internal face, profile or bore of the fish.  
     
     
       31. The fishing tool according to  claim 29 , wherein:
 the latching dogs are repeatedly and selectively movable in an axial sense relative to the cone between a wedged position and a non-wedged position.    
     
     
       32. The fishing tool according to  claim 31 , wherein:
 in the wedged position, the cone is configured to wedge the latching dogs against the fish, and   in the non-wedged position, the latching dogs are radially and/or axially spaced away from the cone, so as to allow disengagement the fishing tool from the fish.    
     
     
       33. The fishing tool according to  claim 32 , wherein:
 the cone is configured to force the latching dogs to move radially in a first radial direction when the latching dogs axially slide against the cone,   in the wedged position, the cone is configured to substantially restrain the latching dogs against radial movement in a second radial direction, opposite the first radial direction, and   in the non-wedged position, the latching dogs are configured to be allowed to move radially in the first radial direction or the second radial direction.    
     
     
       34. The fishing tool according to  claim 29 , wherein the latching dogs are configured to engage with an external face or profile of the fish, and the latching dogs are positioned radially inwards of the cone.  
     
     
       35. The fishing tool according to  claim 34 , wherein the fish includes the external profile provided on the external face of the fish, and each of the dogs includes a rear shoulder configured to engage the external profile of the fish.  
     
     
       36. The fishing tool according to  claim 35 , wherein the cone is configured to be positioned radially outward of the external face and profile of the fish.  
     
     
       37. The fishing tool according to  claim 29 , wherein the latching dogs are configured to engage with an internal face, bore or profile of the fish, and the latching dogs are positioned radially outwards of the cone.  
     
     
       38. The fishing tool according to  claim 37 , wherein the fish includes the internal profile provided in the bore, and each of the dogs includes a rear shoulder configured to engage the internal profile.  
     
     
       39. The fishing tool according to  claim 38 , wherein the cone is configured to enter inside of the bore of the fish.  
     
     
       40. The fishing tool according to  claim 1 , wherein the direct mechanical force link comprises a rotating shaft, a rotation-to-linear converter, a disengagement sleeve and latching fingers with ends on which the latching dogs are arranged.  
     
     
       41. The fishing tool according to  claim 9 , wherein the direct mechanical force link comprises a rotating shaft, a rotation-to-linear converter, a disengagement sleeve and latching fingers with ends on which the latching dogs are arranged.