Expandable underreamer/stabilizer

• US 20030155155A1
• Filed: 02/19/2002
• Published: 08/21/2003
• Est. Priority Date: 02/19/2002
• Status: Active Grant

• Current Assignee: Smith International Incorporated (Schlumberger NV)
• Original Assignee: Smith International Incorporated (Schlumberger NV)
• Inventors: Xu, Wei, Dewey, Charles H.
• Granted Patent: US 6,732,817 B2
• Time in Patent Office: Days
• US Class Current: 175/57
• CPC Class Codes: E21B 10/322 cutter shifted by fluid pressure E21B10/345 takes precedence
• CPC Class Codes: E21B 17/1014 Flexible or expansible centering means, e.g. with pistons pressing against the wall of the well E21B17/1042 takes precedence
• CPC Class Codes: E21B 7/067 with means for locking sections of a pipe or of a guide for a shaft in angular relation, e.g. adjustable bent sub

Abstract

A downhole tool is disclosed that functions as an underreamer, or alternatively, as a stabilizer in an underreamed borehole. An embodiment of the tool includes one or more moveable arms disposed within a body having a flowbore therethrough in fluid communication with the wellbore annulus. The tool alternates between collapsed and expanded positions in response to differential fluid pressure between the flowbore and the wellbore annulus. In one embodiment, the tool moves automatically in response to differential pressure. In a second embodiment, the tool must be selectively actuated before it is moveable. When the tool expands, the arms are preferably translated axially upwardly, while simultaneously being extended radially outwardly from the body. The expanded tool diameter is adjustable at the surface without changing components. The arms may include borehole engaging pads that comprise cutting structures or wear structures or both, depending upon the function of the tool.

Claims

1. An expandable downhole tool for use in a drilling assembly positioned within a wellbore, comprising:

a tubular body including a plurality of angled channels and an axial flowbore extending therethrough; and

at least one moveable arm;

wherein said at least one moveable arm translates along said plurality of angled channels between a collapsed position and an expanded position in response to a differential pressure between said axial flowbore and said wellbore.

2. The tool of claim 1 further including means for adjusting said expanded position.

3. The tool of claim 1 further including at least one nozzle that translates with said at least one moveable arm.

4. The tool of claim 1 further including a spring to bias said at least one moveable arm to said collapsed position.

5. The tool of claim 1 wherein said tool body further includes at least one axial recess for storing said at least one moveable arm in said collapsed position.

6. The tool of claim 1 wherein said at least one moveable arm includes a plurality of extensions corresponding to and engaging said plurality of channels.

7. The tool of claim 1 wherein said at least one moveable arm comprises three moveable arms spaced apart circumferentially around said tool body.

8. The tool of claim 1 wherein said at least one moveable arm includes angled surfaces for connecting into said body.

9. The tool of claim 1 further including a piston that translates said at least one moveable arm axially upwardly from said collapsed position to said expanded position.

10. The tool of claim 1 wherein said at least one moveable arm engages said wellbore in said expanded position.

11. The tool of claim 10 wherein said at least one moveable arm includes at least one set of cutting structures for underreaming said wellbore in said expanded position.

12. The tool of claim 10 wherein said at least one moveable arm includes at least one wear structure for stabilizing said drilling assembly within said wellbore.

13. The tool of claim 1 further including a chamber in fluid communication with said flowbore and said wellbore.

14. The tool of claim 13 wherein said chamber enlarges as said at least one moveable arm translates from said collapsed position to said expanded position.

15. The tool of claim 13 further including an inner member with ports therethrough that enable fluid communication between said chamber and said flowbore.

16. The tool of claim 15 further including means for selectively opening and closing said ports.

17. The tool of claim 15 further including a stinger biased to close said ports, thereby preventing said at least one moveable arm from translating between said collapsed position and said expanded position in response to said differential pressure.

18. The tool of claim 17 further including an actuator for aligning said stinger to open said ports.

19. An expandable downhole tool for use in a drilling assembly positioned within a wellbore having an original diameter borehole and an enlarged diameter borehole, comprising:

a body; and

at least one non-pivotable, moveable arm;

wherein said at least one arm is moveable between a first position defining a collapsed diameter that is smaller than said original diameter borehole, and a second position defining an expanded diameter approximately equal to said enlarged diameter borehole.

20. The tool of claim 19 wherein said at least one arm further comprises cutting structures for underreaming said original diameter borehole to produce said enlarged diameter borehole.

21. The tool of claim 19 wherein said at least one arm further comprises wear structures for stabilizing said drilling assembly within said enlarged diameter borehole.

22. The tool of claim 19 wherein said at least one arm is moveable between said first position and said second position in response to a differential fluid pressure.

23. The tool of claim 22 wherein said at least one arm is automatically moveable from said first position to said second position whenever said differential pressure is present.

24. The tool of claim 22 wherein said tool is selectively actuatable to enable said at least one arm to be moveable from said first position to said second position whenever said differential pressure is present.

25. A method of underreaming a wellbore to form an enlarged borehole and controlling the directional tendencies of a drilling assembly within the enlarged borehole, comprising:

using a drill bit to drill the wellbore;

disposing a first expandable tool having at least one arm configured for underreaming directly above the conventional drill bit;

using the first expandable tool to form the enlarged borehole;

disposing a second expandable tool having at least one arm configured for stabilizing above the first expandable tool; and

using the second expandable tool to control the directional tendencies of the drilling assembly within the enlarged borehole;

wherein both the first expandable tool and the second expandable tool operate between a collapsed position and an expanded position.

26. The method of claim 25 further including providing an indication at the surface corresponding to the position of the first expandable tool and the position of the second expandable tool.

27. The method of claim 25 wherein the first expandable tool and the second expandable tool have the same design except for the configuration of the respective arms.

28. The method of claim 27 wherein both the first expandable tool and the second expandable tool automatically translate between the collapsed position and the expanded position in response to a differential pressure.

29. The method of claim 27 wherein each of the first expandable tool and the second expandable tool must be selectively aligned to enable translation between the collapsed position and the expanded position in response to a differential pressure.

30. The method of claim 25 wherein the first expandable tool automatically translates between the collapsed position and the expanded position and the second expandable tool must be selectively aligned to enable translation between the collapsed position and the expanded position.

31. The method of claim 25 wherein the first expandable tool must be selectively aligned to enable translation between the collapsed position and the expanded position and the second expandable tool automatically translates between the collapsed position and the expanded position.

32. An expandable downhole tool for use in a drilling assembly, comprising:

a body including a plurality of angled channels;

at least one non-pivotable, moveable arm that translates along said angled channels between a collapsed position and an expanded position; and

at least one moveable nozzle that translates to remain adjacent said at least one moveable arm.

33. The tool of claim 32 further including means for adjusting said expanded position.

34. The tool of claim 32 further including a plurality of extensions that engage said angled channels.

35. The tool of claim 32 further including means to prevent the translation of said at least one moveable arm between said collapsed position and said expanded position.

36. The tool of claim 32 wherein said tool has a hydraulic capacity greater than a drill bit of said drilling assembly.