Downhole isolation valve and methods for use

1. A well bore casing string comprising:

at least one valve member having a first position wherein a bore of a casing is substantially unobstructed and a second position wherein the bore is substantially closed;

at least one fluid chamber having a boundary comprising at least two spaced apart walls and having a first pressure configuration isolated from a fluid pressure and a second pressure configuration wherein the fluid pressure is communicated through an inner wall of said at least two spaced apart walls of the boundary of the chamber; and

at least one valve retainer operatively coupled between the fluid chamber and the valve member, the valve retainer configured to move in response to the communicated fluid pressure and to thereby facilitate movement of the valve member from the first position to the second position.

2. The well bore casing string of claim 1 , wherein the fluid pressure is higher than the first pressure configuration.

3. The well bore casing string of claim 1 , wherein the fluid pressure is lower than the first pressure configuration.

4. The well bore casing string of claim 1 , wherein the valve member comprises a flapper valve.

5. The well bore casing string of claim 1 , wherein the valve member comprises a ball valve.

6. The well bore casing string of claim 1 , wherein the valve retainer is configured to release the valve member from retention in the first position.

7. The well bore casing string of claim 1 , wherein the valve retainer is configured to exert a motive force upon the valve member.

8. The well bore casing string of claim 1 , wherein the second pressure configuration comprises a deformation of only said one wall.

9. The well bore casing string of claim 8 , wherein the deformation comprises at least one opening through only said one wall.

10. The well bore casing string of claim 9 , wherein the at least one opening comprises a drilled boundary.

11. The well bore casing string of claim 9 , wherein the at least one opening comprises a perforation formed by at least one of erosion and corrosion.

12. The well bore casing string of claim 1 , wherein the valve member is frangible.

13. The well bore casing string of claim 12 , wherein the valve member comprises a ceramic material.

14. The well bore casing string of claim 13 , wherein the ceramic material comprises glass.

15. The well bore casing string of claim 1 , further comprising a biasing member configured to bias the valve member toward the second position.

16. The well bore casing string of claim 15 , wherein the biasing member comprises a spring.

17. A method for isolating a portion of a well bore comprising:

providing a first fluid flow path having a first designated location, from the well bore to a formation surrounding the well bore and a valve member, configured to selectively obstruct a bore of casing located along the well bore between the first designated location and an earth surface opening of the well bore; and

opening a second fluid flow path, having a second designated location, through a wall of the casing and obstructing the bore of the casing with the valve member, by activating a first energetic device, the second designated location being along the well bore between the valve member and the earth surface opening, wherein the valve member is operatively engaged with an initially closed fluid chamber comprising an inner wall and said step of obstructing comprises transferring fluid pressure through the inner wall of the fluid chamber by activating the first energetic device thereby moving the valve member.

18. The method of claim 17 , further comprising opening a third fluid flow path having a third designated location, through the wall of the casing and obstructing the bore of the casing with a second valve member that is located along the well bore between the second designated location and the earth surface opening, by activating an energetic device, the third designated location being along the well bore between the second valve member and the earth surface opening.

19. The method of claim 18 , wherein the energetic device is a second energetic device and further comprising removing the first energetic device.

20. The method of claim 18 , wherein the energetic device comprises the first energetic device.

21. The method of claim 17 , wherein at least a portion of the valve member is frangible.

22. The method of claim 21 , wherein at least a portion of the valve member is glass.

23. The method of claim 21 , further comprising breaking the frangible portion.

24. The method of claim 17 , wherein transferring comprises deforming the boundary.

25. The method of claim 24 , wherein deforming comprises drilling.

26. The method of claim 24 , wherein deforming comprises at least one of eroding and corroding.

27. The method of claim 24 , wherein deforming comprising perforating with an explosive charge.

28. The method of claim 24 , wherein deforming comprises denting.

29. A downhole isolation valve for use in a tubular comprising:

a closed chamber comprising two boundary walls;

a fluid isolated within the closed chamber;

a valve retainer configured to move in response to a pressure change in the fluid;

an energetic device configured to initiate the pressure change upon impinging only an inner wall of the two boundary walls; and

a valve member operatively engaged with the valve retainer and configured to move from a first position to a second position upon movement of the valve retainer.

30. The downhole isolation valve of claim 29 , wherein the fluid is a hydraulic fluid.

31. The downhole isolation valve of claim 30 , wherein the fluid is of a fixed volume within the chamber.

32. The downhole isolation valve of claim 29 , further comprising a biasing member for biasing the valve retainer toward an actuated position.

33. The downhole isolation valve of claim 32 , wherein the biasing member is a spring.

34. The downhole isolation valve of claim 32 , further comprising a port for providing fluid communication between a biased side of the valve retainer and a bore of the tubular.

35. The downhole isolation valve of claim 29 , further comprising a hole in only the inner wall of the two boundary walls of the closed chamber created by the energetic device configured to change the pressure in the fluid.

36. The downhole isolation valve of claim 29 , further comprising a dent in only the inner wall of the two boundary walls of the closed chamber created by the energetic device configured to change the pressure in the fluid.

37. A well bore casing string comprising:

at least one valve member having a first position wherein a bore of a casing is substantially unobstructed and a second position wherein the bore is substantially closed;

at least one fluid chamber having a boundary comprising at least two spaced apart walls and having a first pressure configuration isolated from a fluid pressure and a second pressure configuration wherein the fluid pressure is communicated through an inner wall of said at least two spaced apart walls of the boundary of the chamber, said second pressure configuration comprises at least one detonated shaped charge perforation through only said inner wall; and

at least one valve retainer operatively coupled between the fluid chamber and the valve member, the valve retainer configured to move in response to the communicated fluid pressure and to thereby facilitate movement of the valve member from the first position to the second position.

38. A method for isolating a portion of a well bore comprising:

providing a first fluid flow path having a first designated location, from the well bore to a formation surrounding the well bore and a valve member, configured to selectively obstruct a bore of casing located along the well bore between the first designated location and an earth surface opening of the well bore;

opening a second fluid flow path, having a second designated location, through a wall of the casing and obstructing the bore of the casing with the valve member, by activating a first energetic device, the second designated location being along the well bore between the valve member and the earth surface opening, wherein the valve member is operatively engaged with an initially closed fluid chamber comprising an inner wall and said step of obstructing comprises transferring fluid pressure through the inner wall of the fluid chamber by activating the first energetic device thereby moving the valve member; and

flowing a fluid from the well bore through the second fluid flow path to an exterior of the casing.

39. A method for isolating a portion of a well bore comprising:

providing a first fluid flow path having a first designated location, from the well bore to a formation surrounding the well bore and a valve member, configured to selectively obstruct a bore of casing located along the well bore between the first designated location and an earth surface opening of the well bore;

opening a second fluid flow path, having a second designated location, through a wall of the casing and obstructing the bore of the casing with the valve member, by activating a first energetic device, the second designated location being along the well bore between the valve member and the earth surface opening, wherein the valve member is operatively engaged with an initially closed fluid chamber comprising an inner wall and said step of obstructing comprises transferring fluid pressure through the inner wall of the fluid chamber by activating the first energetic device thereby moving the valve member;

opening a third fluid flow path having a third designated location, through the wall of the casing and obstructing the bore of the casing with a second valve member that is located along the well bore between the second designated location and the earth surface opening, by activating an energetic device, the third designated location being along the well bore between the second valve member and the earth surface opening; and

flowing a fluid from the well bore through the third fluid flow path to an exterior of the casing.

40. A method for isolating a portion of a well bore comprising:

providing a first fluid flow path having a first designated location, from the well bore to a formation surrounding the well bore and a valve member, configured to selectively obstruct a bore of casing located along the well bore between the first designated location and an earth surface opening of the well bore;

opening a second fluid flow path, having a second designated location, through a wall of the casing and obstructing the bore of the casing with the valve member, by activating a first energetic device, the second designated location being along the well bore between the valve member and the earth surface opening, wherein the valve member is operatively engaged with an initially closed fluid chamber comprising an inner wall and said step of obstructing comprises transferring fluid pressure through the inner wall of the fluid chamber by activating the first energetic device thereby perforating the inner wall with an explosive charge and moving the valve member.