Dual isolation mechanism of cementation port

1. An apparatus for providing fluid communication in a wellbore, comprising:

a housing having a port;

an inner sleeve that is movable in a first direction to open the port and movable in a second direction to seal the port, wherein the second direction is opposite the first direction;

a seal sleeve adapted to seal the port, wherein the seal sleeve is disposed between the inner sleeve and the housing and is configured to selectively engage the housing to form a metal to metal seal; and

a locking member for selectively connecting the inner sleeve to the seal sleeve when the port is open, whereby the seal sleeve is movable with the inner sleeve to seal the port.

2. The apparatus of claim 1 , wherein the port is sealed using the metal to metal seal.

3. The apparatus of claim 1 , further comprising a sealing member disposed in the housing for contacting the seal sleeve.

4. The apparatus of claim 3 , wherein the sealing member is non-elastomeric.

5. The apparatus of claim 4 , wherein the sealing member is metal.

6. The apparatus of claim 5 , wherein the seal sleeve includes a metal surface for contacting the sealing member.

7. The apparatus of claim 6 , wherein the seal sleeve engages the sealing member at a first radial distance and a second sealing member at a second and decreased radial distances.

8. The apparatus of claim 7 , wherein the seal sleeve is tapered at one end.

9. The apparatus of claim 3 , wherein the inner sleeve includes a second sealing member for sealing contact with the housing.

10. The apparatus of claim 1 , wherein the inner sleeve includes a sealing member for sealing contact with the housing.

11. The apparatus of claim 1 , wherein the locking member comprises a snap ring.

12. The apparatus of claim 1 , further comprising a second locking member for connecting the seal sleeve to the housing.

13. The apparatus of claim 1 , wherein the inner sleeve is selectively movable relative to the seal sleeve.

14. A method of controlling fluid communication through a port of a ported tool disposed in a wellbore, comprising:

providing one or more sealing members adjacent to each side of the port;

moving an inner sleeve in a first direction to open the port;

supplying fluid through the port;

attaching the inner sleeve to a seal sleeve for movement therewith after opening the port; and

moving the seal sleeve and the inner sleeve in a second direction opposite the first direction from one side of the port into contact with the one or more sealing members on each side of the port, thereby closing off the port.

15. The method of claim 14 , further comprising securing the seal sleeve to a wall of the ported tool.

16. The method of claim 14 , wherein engaging the seal sleeve to the one or more sealing members comprises deforming the one or more sealing members.

17. The method of claim 14 , wherein the one or more sealing members comprise a non-elastomeric seal.

18. The method of claim 17 , wherein the one or more sealing members comprise a metal.

19. The method of claim 17 , wherein the seal sleeve comprises a non-elastomeric surface for contacting the one or more sealing members.

20. The method of claim 14 , wherein the seal sleeve is tapered at one end.

21. The method of claim 14 , wherein the inner sleeve is moved in a first direction to open the port, and the seal sleeve is moved in a second direction to close the port.

22. A method of cementing a wellbore, comprising:

positioning a casing string in the wellbore, wherein the casing string includes a ported tool having a port in a housing;

providing a seal sleeve having a sealing portion disengaged from the housing;

supplying cement through the bottom of the casing string;

opening the port by moving an inner sleeve in a first direction relative to the seal sleeve;

supplying more cement through the port; and

moving the inner sleeve and the seal sleeve in a second direction opposite the first direction across the port, wherein the sealing portion engages the housing to form a metal to metal seal to close the port.

23. The method of claim 22 , further comprising connecting the inner sleeve to the seal sleeve for simultaneous movement after opening the port.

24. The method of claim 23 , further comprising connecting the seal sleeve to the housing containing the port after closing.

25. The method of claim 24 , further comprising activating a packer prior to supplying more cement through the port.

26. The method of claim 24 , further comprising engaging the seal sleeve to a plurality of sealing members on the housing.

27. The method of claim 26 , further comprising providing the inner sleeve with a plurality of sealing members for sealing contact with the housing.

28. The method of claim 22 , wherein the inner sleeve is moved in a first direction to open the port, and the seal sleeve is moved in a second direction to close the port.

29. An apparatus for providing fluid communication in a wellbore, comprising:

a housing having a port;

an inner sleeve adapted to seal the port, the inner sleeve movable in a first direction to open the port, and movable in a second direction opposite the first direction to close the port; and

a seal sleeve adapted to seal the port, wherein the seal sleeve is disposed between the inner sleeve and the housing and is movably disposed on only one side of the port when the port is open, and wherein the seal sleeve is selectively attachable with the inner sleeve in operation for moving with the inner sleeve to close the port.

30. The apparatus of claim 29 , wherein the inner sleeve has:

a first position where the inner sleeve is movable independently of the seal sleeve; and

a second position where the inner sleeve is movable with the seal sleeve.

31. The apparatus of claim 30 , wherein the port is sealed using a metal to metal seal.

32. The apparatus of claim 30 , further comprising a sealing member disposed in the housing for contacting the seal sleeve.

33. The apparatus of claim 32 , wherein the sealing member is non-elastomeric.

34. The apparatus of claim 33 , wherein the sealing member is metal.

35. The apparatus of claim 34 , wherein the seal sleeve includes a metal surface for contacting the sealing member.

36. The apparatus of claim 35 , wherein the seal sleeve engages two sealing members at a first radial distance and at a second and decreased radial distance.

37. The apparatus of claim 32 , wherein the inner sleeve includes a second sealing member for sealing contact with the housing.

38. The apparatus of claims 30 , wherein the inner sleeve includes a sealing member for sealing contact with the housing.

39. The apparatus of claim 29 , further comprising a connection member for connecting the inner sleeve to the seal sleeve.

40. The apparatus of claim 39 , further comprising a second locking member for connecting the seal sleeve to the housing.

41. The apparatus of claim 39 , wherein the connection member comprises a snap ring.