Fishing tool

Abstract

A packer tool ( 10 ) for milling and retrieving a packer from the casing of a well bore is provided. The tool ( 10 ) comprises an upper milling portion ( 14 ), a lower attachment portion ( 16 ) at least partially located within the upper milling portion ( 14 ), and a debris retainer ( 28,128,228 ) for capturing milled cuttings within the tool ( 10 ). A method of milling and retrieving a packer using the tool is also provided.

1 . A packer tool comprising an upper milling portion, a lower attachment portion at least partially located within the upper milling portion, and a debris retainer for capturing milled cuttings within the tool. 
     
     
         2 . A tool according to  claim 1 , wherein the upper milling portion comprises:
 a sleeve which at least partially encloses the lower attachment portion such that an annular chamber is defined between the sleeve and the lower attachment portion; and   a mill provided on an open end of the sleeve.   
     
     
         3 . A tool according to  claim 2 , wherein the sleeve has a closed end remote from the open end, and the debris retainer comprises a filter portion which permits fluid flow from the annular chamber to the exterior of the tool. 
     
     
         4 . A tool according to  claim 2  and further comprising one or more return flow ports which permit additional fluid flow from the annular chamber to the exterior of the tool. 
     
     
         5 . A tool according to  claim 4 , wherein the debris retainer further comprises a strainer or filter located in the or each return flow port. 
     
     
         6 . A tool according to  claim 2 , wherein the debris retainer further comprises a basket portion located within the annular chamber, the basket portion preventing any debris in the annular chamber from passing out of the open end of the sleeve. 
     
     
         7 . A tool according to  claim 6 , wherein the debris retainer further comprises a diverter plate located in the annular chamber and adapted to divert fluid flow in the chamber towards the basket portion. 
     
     
         8 . A tool according to  claim 6 , wherein the basket portion is formed from a plurality of biased finger members, the finger members being biased towards a closed position in which debris is prevented from passing out of the open end of the sleeve. 
     
     
         9 . A tool according to  claim 2 , wherein the debris retainer further comprises one or more magnets located in the annular chamber. 
     
     
         10 . A tool according to  claim 1  and further comprising:
 a central bore extending axially through the tool; and   one or more flow diversion ports providing fluid communication from the central bore to the exterior of the tool are located in the tool to provide fluid flow from the central bore to the outer surface of the tool.   
     
     
         11 . A tool according to  claim 10 , wherein the or each flow diversion port includes a nozzle to direct a jet of fluid out of the port. 
     
     
         12 . A tool according to  claim 10  wherein the central bore includes a ball seat located downstream of the flow diversion ports. 
     
     
         13 . A tool according to  claim 12 , wherein the ball seat is shearable from the central bore. 
     
     
         14 . A method of retrieving a packer from a well bore, the method comprising the steps of:
 (a) running a tool according to  claim 1  on a work string;   (b) engaging the lower attachment portion to the packer;   (c) milling the packer with the upper milling portion to free the packer; and   (d) removing the work string from the well bore while retaining milled cuttings in the debris retainer.   
     
     
         15 . A method according to  claim 14 , and further comprising the step of dropping a ball onto a ball seat in the tool so as to divert fluid flow from the work string through one or more flow diversion ports to the exterior of the tool. 
     
     
         16 . A method according to  claim 15 , wherein the ball seat is shearable and the method further comprises increasing the pressure in the tool until the ball seat shears, thereby resuming fluid flow through the tool.