Expandable bit with secondary release device

• US 6,953,096 B2
• Filed: 12/31/2002
• Issued: 10/11/2005
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: Weatherford Technology Holdings, LLC (Weatherford International PLC)
• Original Assignee: Weatherford/Lamb Incorporated (Weatherford International PLC)
• Inventors: Fuller, Mark S., Gledhill, Andrew D., Dalrymple, Kenneth J.
• Primary Examiner(s): NEUDER, WILLIAM P
• Application Number:
  US10/335,957
• Publication Number:
  US 20040124011A1
• Time in Patent Office: 1,015 Days
• Field of Search: 175/57, 175/267, 175/269, 175/271
• US Class Current: 175/57
• CPC Class Codes: E21B 10/322 cutter shifted by fluid pressure E21B10/345 takes precedence
• CPC Class Codes: E21B 10/62 characterised by parts, e.g. cutting elements, which are detachable or adjustable E21B10/64 takes precedence; for roller bits E21B10/20; for augers E21B10/44

Abstract

The present invention generally relates to an apparatus and method of forming a wellbore. In one aspect, an expandable bit for use in a wellbore is provided. The expandable bit includes a body and a blade assembly disposed on the body. The blade assembly is movable between a closed position whereby the expandable bit has a smaller outer diameter and an open position whereby the expandable bit has a larger outer diameter. The expandable bit further includes a release assembly for providing a secondary means to move the blade assembly from the open position to the closed position. In another aspect, a method of forming a wellbore is provided. In yet another aspect, an expandable apparatus for use in forming a wellbore is provided.

Claims

1. An expandable bit for use in a wellbore, comprising:

a body;

a blade assembly disposed on the body, the blade assembly movable between a closed position whereby the expandable bit has a smaller outer diameter and an open position whereby the expandable bit has a larger outer diameter; and

a release assembly for allowing the blade assembly to move from the open position to the closed position, wherein the release assembly comprises a shearable connection between the body and the blade assembly.

2. The expandable bit of claim 1, wherein a predetermined axial force applied to the expandable bit activates the release assembly.

3. The expandable bit of claim 1, wherein the release assembly is disposed between the blade assembly and the body.

4. The expandable bit of claim 1, wherein the shearable connection is formed by engaging a connection means on the body with a mating connection means on the blade assembly.

5. The expandable bit of claim 4, wherein the connection means and the mating connection means are constructed and arranged from at least one thread.

6. The expandable bit of claim 1, wherein the release assembly comprises a shear pin connecting the body to the blade assembly.

7. The expandable bit of claim 6, wherein a predetermined axial force causes the shear pin to fail allowing the blade assembly to move from the open position to the closed position.

8. A method of forming a wellbore, comprising:

lowering a drill string with an expandable bit at the end thereof through a first diameter portion of a wellbore, the expandable bit including;

a body;

cutting members disposed on the body, the cutting members movable between a collapsed position and an expanded position; and

a release assembly for allowing the cutting members to move from the expanded position to the collapsed position, wherein the release assembly comprises a shearable connection between the body and the cutting members;

causing the expandable bit to move from the collapsed position to the expanded position;

rotating the expandable bit to form a portion of the wellbore;

operating the release assembly to move the cutting members to the collapsed position; and

removing the drill string and the expandable bit from the wellbore.

9. The method of claim 8, further including pumping fluid through the expandable bit.

10. The method of claim 9, further including creating a pressure differential in a bore of the body to open the cutting members.

11. The method of claim 10, further including reducing the flow of fluid through the expandable bit.

12. The method of claim 8, wherein the shearable connection is formed by engaging a connection means on the body with a mating connection means on the cutting members.

13. The method of claim 12, wherein the connection means and the mating connection means are constructed and arranged from at least one thread.

14. The method of claim 8, wherein the release assembly comprises a shear pin that connects the body to the cutting members.

15. The expandable bit of claim 14, wherein a predetermined axial force shears the shear pin causing the cutting members to move from the expanded position to the collapsed position.

16. The method of claim 8, further including applying an axial force to the expandable bit to operate the release assembly.

17. An expandable apparatus for use in forming a wellbore, comprising:

a body;

cutting members disposed on the body, the cutting members movable between a collapsed position and an expanded position; and

a release assembly for allowing the cutting members to move from the expanded position to the collapsed position, wherein the release assembly comprises a shearable connection between the body and the cutting members.

18. The expandable apparatus in claim 17, wherein a predetermined axial force applied to the expandable bit activates the release assembly.

19. An expandable apparatus for use in forming a wellbore, comprising:

a body having a slidable member;

at least two cutting members disposed on the body, the at least two cutting members movable between a collapsed position and an expanded position; and

a re-settable release assembly for allowing the at least two cutting members to move from the expanded position to the collapsed position, the re-settable release assembly comprising an outwardly biased ring movable radially inward upon contact with the slidable member.

20. The expandable apparatus in claim 19, wherein a predetermined axial force applied to the expandable bit moves a hydraulic cylinder in relation to a blade pivot housing, thereby activating the re-settable release assembly.

21. The expandable apparatus in claim 19, wherein the re-settable release assembly includes a member that moves between a larger diameter position and a smaller diameter position, the member biased towards the larger diameter position.

22. The expandable apparatus in claim 21, wherein the at least two cutting members assume the expanded position when the member is in the larger diameter position.

23. A method for drilling a portion of a wellbore, comprising:

lowering an expandable cutting apparatus in the wellbore;

expanding the expandable cutting apparatus;

rotating the expandable cutting apparatus and drilling a portion of the wellbore; and

collapsing the expandable cutting apparatus by activating a re-settable release assembly having an outwardly biased ring, wherein the ring is urged radially inward to allow the expandable cutting apparatus to collapse.

24. A method for drilling a portion of a wellbore, comprising:

positioning an expandable cutting apparatus in the wellbore;

moving the expandable cutting apparatus from a closed position to an open position;

rotating the expandable cutting apparatus and drilling a portion of the wellbore; and

shearing a shearable connection to allow the expandable cutting apparatus to move from the open position to the closed position.