Downhole assembly for selectively sealing off a wellbore
Downhole assemblies and methods for isolating a wellbore. A downhole tool can include a body having a bore or flowpath formed therethrough, and one or more sealing members disposed therein. The one or more sealing members can include an annular base and a curved surface having an upper face and a lower face, wherein one or more first radii define the upper face, and one or more second radii define the lower face, and wherein, at any point on the curved surface, the first radius is greater than the second radius. The sealing members can be disposed within the bore of the tool using one or more annular sealing devices disposed about the one or more sealing members.
1. An assembly for sealing off a bore of a downhole tool, comprising:
a curved surface having an outer face and an inner face, wherein the outer face has a convex configuration and the inner face has a concave configuration, the outer face and the inner face of the curved surface having a distance therebetween;
an annular base depending from the curved surface, the annular base comprising a cylindrical inner surface and a cylindrical outer surface having a distance therebetween, the distance between the cylindrical inner surface and the cylindrical outer surface of the annular base being the same as the distance between the outer face and the inner face of the curved surface; and
a first circular seal contacting an exterior surface of the annular base, the first seal configured to form a fluid barrier between at least the annular base and the first seal when the assembly is mounted in a downhole tool.
2. The assembly of claim 1 , further comprising a second seal disposed about the outer face of the curved surface.
3. The assembly of claim 2 , wherein the first seal is an O-ring, and the second seal is a crush seal.
4. The assembly of claim 1 , wherein the outer face of the curved surface comprises a perimeter where the convex configuration ends and a distance between opposing sides of the perimeter, and the annular base has an outer diameter, the outer diameter of the annular base being the same as the distance between the opposing sides of the perimeter such that the annular base is within a perpendicular projection of the perimeter of the curved surface.
5. The assembly of claim 1 , wherein the curved surface and the annular base are an integral unit composed of the same material.
6. The assembly of claim 1 , further comprising a second seal disposed about the annular base.
7. The assembly of claim 1 , wherein the first seal is located adjacent a portion of the annular base distal from the curved surface.
8. The assembly of claim 7 , wherein the first seal is compressed by an outer surface of the annular base and an inner wall of the downhole tool when the assembly is mounted in a downhole tool.
9. The assembly of claim 8 , wherein the first seal is held in place by a groove.
10. The assembly of claim 1 , wherein the first seal is compressed by an outer surface of the annular base and an inner wall of the downhole tool when the assembly is mounted in a downhole tool.
11. The assembly of claim 1 , wherein the annular base has a first end proximal the curved surface and a second end distal from the curved surface, and the first seal is located near the first end of the annular base.
12. The assembly of claim 11 , wherein the first seal is compressed by an outer surface of the annular base and an inner wall of the downhole tool when the assembly is mounted in a downhole tool.
13. The assembly of claim 12 , wherein the first seal is held in place by a groove.
14. An assembly for sealing off a bore of a downhole tool, comprising:
a curved surface having an outer face and an inner face, wherein the outer face has a convex configuration and the inner surface has a concave configuration, the outer face having a perimeter where the convex configuration ends and a distance between opposing sides of the perimeter;
an annular base depending from the perimeter of the outer face, the annular base having an outer diameter and an inner bore, the outer diameter of the annular base being substantially the same as the distance between the opposing sides of the perimeter such that the annular base is within a perpendicular projection of the perimeter of the curved surface; and
a first circular seal contacting an exterior surface of the annular base, the first seal configured to form a fluid barrier between at least the annular base and the first seal when mounted in a downhole tool.
15. The assembly of claim 14 , further comprising a second seal disposed about the outer face of the curved surface.
16. The assembly of claim 15 , wherein the first seal is an O-ring, and the second seal is a crush seal.
17. The assembly of claim 14 , wherein the annular base comprises a cylindrical inner surface and a cylindrical outer surface having a distance therebetween, the inner face of the curved surface has a height at its apex, and twice the distance between the cylindrical inner surface and the cylindrical outer surface of the annular base is less than the height of the inner face of the curved surface.
18. The assembly of claim 14 , wherein the curved surface and the annular base are an integral unit composed of the same material.
19. The assembly of claim 14 , further comprising a second seal disposed about the annular base.
20. The assembly of claim 14 , wherein the first seal contacts a portion of the annular base distal from the curved surface.
21. The assembly of claim 20 , wherein the first seal is compressed by an outer surface of the annular base and an inner wall of the downhole tool when the assembly is mounted in a downhole tool.
22. The assembly of claim 21 , wherein the first seal is held in place by a groove.
23. The assembly of claim 14 , wherein the first seal is compressed by an outer surface of the annular base and an inner wall of the downhole tool when the assembly in inserted in a downhole tool.
24. The assembly of claim 14 , wherein the annular base has a first end proximal the curved surface and a second end distal from the curved surface, and the first seal is located near the first end of the annular base.
25. The assembly of claim 24 , wherein the first seal is compressed by an outer surface of the annular base and an inner wall of the downhole tool when the assembly is mounted in a downhole tool.
26. The assembly of claim 25 , wherein the first seal is held in place by a groove.