Expandable roller reamer

Abstract

An expandable downhole tool for use in a drilling assembly positioned within a wellbore includes a tool body having an axial flowbore extending therethrough and a moveable arm. The moveable arm includes a roller structure including cutters and rotatably mounted on the moveable arm. The moveable arm is configured to move outwardly in response to actuation of the expandable downhole tool.

1 . An expandable downhole tool for use in a drilling assembly positioned within a wellbore, the expandable downhole tool comprising:
 a tool body comprising an axial flowbore extending therethrough; and   a moveable arm comprising a roller structure comprising cutters and rotatably mounted on the moveable arm, wherein the moveable arm is configured to move outwardly in response to actuation of the expandable downhole tool.   
   
   
       2 . The expandable downhole tool of  claim 1 , wherein the tubular body comprises a plurality of angled channels formed within a pocket of the tool body and configured to receive corresponding angled extensions formed on the moveable arm, and wherein the moveable arm translates along the plurality of angled channels. 
   
   
       3 . The expandable downhole tool of  claim 1 , wherein the moveable arm comprises a roller pin on which the roller structure is rotatably fixed. 
   
   
       4 . The expandable downhole tool of  claim 3 , wherein the moveable arm comprises two roller mounts configured to hold opposing ends of the roller pin onto the moveable arm. 
   
   
       5 . The expandable downhole tool of  claim 1 , wherein the actuation of the expandable downhole tool occurs in response to differential pressure between the axial flowbore and the wellbore. 
   
   
       6 . The expandable downhole tool of  claim 1 , wherein the cutters are inserts. 
   
   
       7 . The expandable downhole tool of  claim 1 , wherein the expandable downhole tool is selectively actuatable to allow or prevent a fluid flowing through the tubular body to translate the at least one moveable arm between a collapsed position and an expanded position. 
   
   
       8 . The expandable downhole tool of  claim 7 , further comprising a selectively actuatable sleeve that prevents or allows a differential pressure to translate the at least one moveable arm between a collapsed position and an expanded position. 
   
   
       9 . The expandable downhole tool of  claim 1 , wherein the expandable downhole tool comprises a plurality of moveable arms. 
   
   
       10 . The expandable downhole tool of  claim 9 , wherein plurality of moveable arms is spaced circumferentially apart around the tool body. 
   
   
       11 . A moveable arm for an expandable downhole tool, the moveable arm comprising:
 a body;   a roller structure comprising cutters and rotatably mounted on the body, wherein the moveable arm is configured be moveably received into a tool body of the expandable downhole tool.   
   
   
       12 . The moveable arm of  claim 11 , wherein the body comprises angled extensions corresponding to angled channels formed in the tool body. 
   
   
       13 . The moveable arm of  claim 11 , further comprising:
 a roller pin on which the roller structure is rotatably fixed.   
   
   
       14 . The moveable arm of  claim 13 , further comprising:
 two roller mounts configured to hold opposing ends of the roller pin onto the body.   
   
   
       15 . The moveable arm of  claim 11 , wherein the cutters are inserts. 
   
   
       16 . A method of underreaming a wellbore to form an enlarged borehole, comprising:
 using a drill bit to drill the wellbore;   disposing an expandable underreamer above the drill bit;   using the expandable underreamer to enlarge the borehole;   disposing an expandable roller reamer above the first expandable underreamer, wherein the expandable roller reamer comprises a moveable arm comprising a roller structure comprising cutters and rotatably mounted on the moveable arm; and   actuating the expandable roller reamer such that the cutters disposed on the roller structure contact the enlarged borehole.