Expandable bit with secondary release device

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.