Seal with bellows style nose ring and radially drivable lock rings

摘要

A seal assembly between a wellhead housing having a bore and a casing hanger, has an inner seal leg for sealing against a hanger and an outer seal leg for sealing against the housing. A bellows style portion is formed on a nose ring carried by the seal assembly to increase lockdown capacity. The bellows style portion has an inner surface that faces an outer profile of the hanger, and an outer surface that faces the bore of the housing. Inner and outer lock rings are disposed on the bellows style portion. When the bellows style portion is axially collapsed, it radially expands into the bore of the housing and the outer profile of the hanger, and urges the inner and outer lock rings into engagement with the outer profile of the hanger and the bore of the housing.

主权项

1. A wellhead assembly with a central axis, comprising:
an outer wellhead member having a bore; an inner wellhead member located in the bore; a seal ring between and in sealing engagement with the inner and outer wellhead members; a bellows style portion on a lower end of the seal ring, the bellows style portion being axially contractible and having outer surfaces and inner surfaces; and at least two lock rings disposed on the bellows style portion such that axial contraction of the bellows style portion will urge each lock ring into radial engagement with at least one of the inner wellhead member and the outer wellhead member before the outer surfaces of the bellows style portion contact the outer wellhead member and before the inner surfaces of the bellows style portion contact the inner wellhead member.