Stuck packer miller and external retrieval tool

Abstract

A downhole retrieval tool includes: an upper sub-assembly disposed at a proximal end of the retrieval tool; an engagement body disposed axially adjacent to the upper sub-assembly, with respect to a central longitudinal axis of the retrieval tool; and a milling tool disposed at a distal end of the retrieval tool. The engagement body is configured to selectively constrict about a portion of production tubing extending from a packer assembly, the packer assembly comprising a packer element. The milling tool is configured to mill one or more portions at an outer periphery of the packer element. A related method includes deploying and utilizing such a retrieval tool downhole.

1 . A downhole retrieval tool comprising:
 an upper sub-assembly disposed at a proximal end of the retrieval tool;   an engagement body disposed axially adjacent to the upper sub-assembly, with respect to a central longitudinal axis of the retrieval tool; and   a milling tool disposed at a distal end of the retrieval tool;   the engagement body including a grapple that selectively constricts about a portion of production tubing extending from a packer assembly, the packer assembly comprising a packer element,   wherein the grapple has an axial length of about 3 feet, and is installed to reciprocate in an axial direction while simultaneously transmitting a full torsional force to the portion of production tubing; and   the milling tool being configured to mill one or more portions at an outer periphery of the packer element.   
     
     
         2 . The downhole retrieval tool according to  claim 1 , wherein the milling tool comprises:
 a main body portion; and   a milling head disposed on the main body portion,   wherein the milling head is generally annular in shape.   
     
     
         3 . The downhole retrieval tool according to  claim 2 , wherein the packer element comprises a production packer element. 
     
     
         4 . The downhole retrieval tool according to  claim 3 , wherein the upper sub-assembly, engagement body, and milling tool are hollow. 
     
     
         5 . The downhole retrieval tool according to  claim 4 , further comprising a hollow extension portion which extends from the engagement body to the milling tool. 
     
     
         6 . The downhole retrieval tool according to  claim 5 , wherein the extension portion is generally cylindrical in shape. 
     
     
         7 . The downhole retrieval tool according to  claim 6 , wherein the upper sub-assembly comprises:
 a cylindrical upper neck portion;   a frustoconical transition portion disposed axially adjacent to the upper neck portion; and   a cylindrical lower body portion disposed axially adjacent to the transition portion.   
     
     
         8 . The downhole retrieval tool according to  claim 7 , wherein the upper neck portion has a smaller diameter than the lower body portion; and
 wherein the lower body portion is disposed axially adjacent to the extension portion.   
     
     
         9 . (canceled) 
     
     
         10 . A method comprising:
 deploying a downhole retrieval tool into a wellbore, wherein the retrieval tool comprises:
 an upper sub-assembly disposed at a proximal end of the retrieval tool; 
 an engagement body disposed axially adjacent to the upper sub-assembly, with respect to a central longitudinal axis of the retrieval tool, 
 wherein the engagement body includes a grapple having an axial length of about 3 feet; and 
 a milling tool disposed at a distal end of the retrieval tool; 
   disposing the retrieval tool axially adjacent to a packer assembly and a portion of production tubing extending therefrom;   continuing to displace the retrieval tool in a downhole direction such that the retrieval tool surrounds a progressively greater length of the portion of the production tubing;   selectively constricting the grapple about the portion of the production tubing, via reciprocating the grapple in an axial direction while simultaneously transmitting a full torsional force to the portion of production tubing; and   with the milling tool, milling one or more portions at an outer periphery of a packer element of the packer assembly.   
     
     
         11 . The method according to  claim 10 , wherein the constricting and milling are performed in a single run of the retrieval tool downhole. 
     
     
         12 . The method according to  claim 11 , further comprising deploying the retrieval tool uphole after the constricting and milling, thereby retrieving the production tubing and packer assembly. 
     
     
         13 . The method according to  claim 12 , wherein the milling tool comprises:
 a main body portion; and   a milling head disposed on the main body portion,   wherein the milling head is generally annular in shape.   
     
     
         14 . The method according to  claim 13 , wherein the packer element comprises a production packer element. 
     
     
         15 . The method according to  claim 14 , wherein the upper sub-assembly, engagement body, and milling tool are hollow. 
     
     
         16 . The method according to  claim 15 , wherein the production packer element comprises an upper slip, an inflatable packer disposed axially adjacent to the upper slip, and a lower slip disposed axially adjacent to the inflatable packer. 
     
     
         17 . The method according to  claim 16 , wherein the retrieval tool further comprises a hollow extension portion which extends from the engagement body to the milling tool. 
     
     
         18 . The method according to  claim 17 , wherein the extension portion is generally cylindrical in shape. 
     
     
         19 . The method according to  claim 18 , wherein the upper sub-assembly comprises:
 a cylindrical upper neck portion;   a frustoconical transition portion disposed axially adjacent to the upper neck portion; and   a cylindrical lower body portion disposed axially adjacent to the transition portion.   
     
     
         20 . The method according to  claim 19 , wherein the upper neck portion has a smaller diameter than the lower body portion; and
 wherein the lower body portion is disposed axially adjacent to the extension portion.