Flange overshot retrieval tool

Abstract

A tool for removing a first flange from a second flange comprises a housing having a central axis, a first end, and an open second end opposite the first end. The housing also includes a first access port extending radially therethrough. In addition, the tool comprises an annular basket grapple coaxially disposed within the second end of the housing and configured to coaxially receive and engage a first flange. The basket grapple has a first end, a second end opposite the first end, and a cutout extending radially therethrough. The outer surface of the basket grapple includes external threads that engage mating internal threads on the inner surface of the housing. Further, the tool comprises a key releasably coupled to the housing. The key is configured to selectively prevent relative rotation between the basket grapple and the housing.

1 . A tool for removing a first flange from a second flange, the tool comprising:
 a housing having a central axis, a first end, an open second end opposite the first end, a radially inner surface, and a radially outer surface, wherein the housing includes a first access port extending radially from the outer surface to the inner surface;   an annular basket grapple coaxially disposed within the second end of the housing and configured to coaxially receive and engage a first flange, wherein the basket grapple has a first end, a second end opposite the first end, a radially inner surface, a radially outer surface, and a cutout extending radially through the basket grapple from the outer surface to the inner surface;   wherein the outer surface of the basket grapple includes external threads that engage mating internal threads on the inner surface of the housing; and   a key releasably coupled to the housing, wherein the key has a first position extending radially through the first access port and the cutout, and a second position removed from the cutout, wherein the key is configured to prevent relative rotation between the basket grapple and the housing in the first position and allow relative rotation between the basket grapple and the housing in the second position.   
     
     
         2 . The tool of  claim 1 , wherein the basket grapple includes a plurality of circumferentially spaced slots, wherein a each slot extends axially from the second end of the basket grapple and extends radially through the basket grapple from the outer surface of the basket grapple to the inner surface of the basket grapple;
 wherein the plurality of slots define a plurality of circumferentially adjacent fingers configured to flex radially outward.   
     
     
         3 . The tool of  claim 2 , wherein the cutout extends axially from the first end of the basket grapple and one of the plurality of slots extends axially from the second end of the basket grapple to the cutout. 
     
     
         4 . The tool of  claim 2 , wherein the inner surface of the basket grapple includes a plurality of teeth positioned on each finger, wherein the teeth are configured to engage a first flange. 
     
     
         5 . The tool of  claim 1 , further comprising a door releasably coupled to the housing and covering the first access port, wherein the key extends from the door. 
     
     
         6 . The tool of  claim 5 , wherein the door is coupled to the housing with a bolt, wherein the bolt includes a handle extending radially from the housing, wherein the handle is configured to allow a remotely operated vehicle to remove the bolt and manipulate the position of the housing subsea. 
     
     
         7 . The tool of  claim 1 , wherein the housing includes a plurality of circumferentially spaced through slots axially positioned between the first end of the housing and the basket grapple, wherein each through slot in the housing extends radially through the housing from the inner surface of the housing to the outer surface of the housing;
 wherein a plate is mounted to the first end of the housing, the plate including a plurality of circumferentially spaced through bores;   wherein the through slots in the housing and the through bores in the plate are configured to allow fluid flow from the inside of the housing to the outside of the housing.   
     
     
         8 . The tool of  claim 1 , further comprising a plurality of circumferentially spaced guide feet coupled to the second end of the housing, wherein each foot has a first end engaging the housing, a second end extending from the second end of the housing, and a guide surface extending from the second end of the foot. 
     
     
         9 . The tool of  claim 8 , wherein each foot is removably coupled to the housing and includes a finger extending radially inward along the second end of the housing, wherein the fingers of the plurality of guide feet are configured to prevent the basket grapple from moving axially through the second end of the housing. 
     
     
         10 . The tool of  claim 9 , wherein each guide foot is removably coupled to the housing with a bolt, wherein the bolt includes a handle extending radially from the housing, and wherein the handle is configured to allow a remotely operated vehicle to remove the bolt subsea. 
     
     
         11 . A method for removing a first flange of a subsea flange joint from a second flange of the subsea flange joint, the method comprising:
 (a) positioning a flange overshot retrieval tool over the subsea flange joint, wherein the tool comprises:
 a housing having a central axis, a first end, an open second end opposite the first end, a radially inner surface, and a radially outer surface; 
 an annular basket grapple coaxially threaded into the second end of the housing, wherein the basket grapple has a first end, and a second end opposite the first end; 
   (b) receiving the first flange into the basket grapple;   (c) radially expanding the basket grapple during (b); and   (d) removing the first flange from the flange joint after (b).   
     
     
         12 . The method of  claim 11 , further comprising:
 (e) preventing the rotation of the housing relative to the basket grapple with a key extending radially through the housing and the basket grapple.   
     
     
         13 . The method of  claim 11 , wherein (b) further comprises guiding the first flange into the second end of the housing with a plurality of circumferentially spaced guide feet coupled to the second end of the housing;
 wherein each foot has a first end engaging the housing, a second end extending from the second end of the housing, and a guide surface extending axially downward and radially outward from the second end of the housing;   wherein each guide foot includes a finger extending radially inward along the second end of the housing, wherein the fingers of the plurality of guide feet are configured to prevent the basket grapple from moving axially through the second end of the housing.   
     
     
         14 . The method of  claim 11 , wherein the tool is positioned with a pipe string. 
     
     
         15 . The method of  claim 11 , wherein the basket grapple further comprises a plurality of circumferentially spaced slots extending axially from the second end of the basket grapple;
 wherein the plurality of slots define a plurality of fingers at the second end of the basket grapple, each finger including a plurality of teeth disposed on the inner surface of the basket grapple;   wherein (c) further comprises flexing the plurality of fingers radially outward during (b).   
     
     
         16 . The method of  claim 15 , further comprising biasing the teeth radially inward into engagement with the first flange during (b). 
     
     
         17 . A method comprising:
 (a) lowering a flange overshot retrieval tool to a subsea flange joint including a first flange coupled to a second flange, wherein the tool comprises:
 a housing having a central axis, a first end, an open second end opposite the first end, a radially inner surface, and a radially outer surface; 
 an annular basket grapple coaxially disposed in the second end of the housing, wherein the basket grapple has a first end, and a second end opposite the first end; 
   (b) lowering the tool onto the first flange;   (c) capturing the first flange with the basket grapple during (b); and   (d) releasing the first flange from the basket grapple subsea after (c).   
     
     
         18 . The method of  claim 17 , wherein (a) comprises lowering the tool with a pipe string; and
 wherein (d) further comprises:
 rotating the housing and the basket grapple relative to the first flange with the pipe string; and 
   unthreading the basket grapple from the first flange.   
     
     
         19 . The method of  claim 17 , wherein (a) comprises lowering the tool with a pipe string; and
 wherein (d) further comprises:
 rotating the housing relative to the basket grapple and the first flange with the pipe string; and 
 unthreading the housing from the basket grapple. 
   
     
     
         20 . The method of  claim 19 , wherein (d) further comprises:
 removing a plurality of guide feet coupled to the second end of the housing with one or more subsea remotely operated vehicles;   allowing the housing to rotate relative to the basket grapple by removing a key extending radially through the housing and the basket grapple with the one or more subsea remotely operated vehicles.   
     
     
         21 . The method of  claim 20 , further comprising:
 (e) lifting the housing from the basket grapple and the first flange.   
     
     
         22 . The method of  claim 17 , further comprising:
 rotating the housing relative to the basket grapple and the first flange with a pipe string;   accessing the basket grapple subsea through a port extending radially through the housing; and   cutting the basket grapple subsea through the port with a subsea remotely operated vehicles.