Soft Skin Metal Seal and Technique of Manufacture
AssigneeVetco Gray Inc.
InventorsNicholas P. Gette, Stanley Drozdowski
Life of this patent
Estimating the term…
Abstract
A seal assembly between a wellhead housing having a bore and a casing hanger, has an inner seal leg for sealing against hanger and an outer seal leg for sealing against housing. An extension extends downward from outer seal leg and is connected to a nose ring having a downward facing shoulder that rests on the hanger shoulder to provide a reaction point for setting operations. A sealing surface on the seal legs is heat treated to obtain a lower localized yield strength to provide improved sealing while maintaining mechanical load capability.
Claims19
A wellhead assembly with an axis, comprising:
- an outer wellhead member having a bore;
- an inner wellhead member located in the bore;
- opposing seal surfaces in the bore and on an exterior portion of the inner wellhead member;
- a seal ring between the inner and outer wellhead members having an inner annular member and an outer annular member circumscribing a portion of the inner annular member, the inner annular member having an inward facing profile and the outer annular member having an outward facing profile;
- a heat treated seal surface formed on at least one of the inward and outward facing profiles, wherein the heat treated seal surface has a lower yield strength than a remainder of the seal ring;
- and
- an annular energizing ring having a lower end insertable between the inner and outer annular members of the seal ring, so that when the lower end of the energizing ring is inserted between the inner and outer annular members of the seal ring, the inner and outer annular members of the seal ring are urged radially apart from each other to place at least one heat treated seal surface into sealing engagement with the seal surface of one of the inner and outer wellhead members.
A seal assembly for a subsea wellhead assembly, comprising:
- a metal seal ring for sealing between inner and outer wellhead members, in a subsea wellhead assembly, the seal ring having an inner annular member and an outer annular member circumscribing a portion of the inner annular member, the inner and outer annular members being joined at a base, the inner annular member having an inward facing profile and the outer annular member having an outward facing profile;
- an annular energizing ring having a lower end insertable between the inner and outer annular members of the seal ring, so that when the lower end of the energizing ring is inserted between the inner and outer annular members of the seal ring, outer walls of the inner and outer annular members of the seal ring are urged radially apart from each other to place the heat treated seal surface into sealing engagement with one of the inner outer wellhead members;
- an annular extension extending downwards from and located below the seal ring, the extension having a lower surface for landing on a portion of the inner wellhead member and having an upward facing shoulder in contact with the inner annular member of the seal ring;
- and
- a heat treated seal surface formed on at least one of the inward and the outward facing profiles, wherein the heat treated seal surface has a lower yield strength than the base, the annular extension, and the energizing ring.
A method for fabricating a seal assembly, comprising:
- providing a steel alloy seal ring for installation between inner and outer wellhead members having, an inner annular member and an outer annular member circumscribing a portion of the inner annular member, the inner annular member having an inward facing profile and the outer annular member having an outward facing profile;
- and
- heating at least one of the inward or outward facing profiles to a transformation temperature while keeping a remaining portion of the sealing ring below the transformation temperature, thereby lowering the yield strength of at least one profile below a yield strength of the remaining portion.
Dependencies are inferred from the claim text.