Casing hanger lockdown with conical lockdown ring

摘要

A seal seals an annulus in a subsea assembly between a wellhead and a casing hanger landed on a shoulder within a bore of the wellhead. The seal includes a casing hanger seal ring disposed within the annulus. The seal ring engaged with an inner diameter surface of the wellhead, and engaged with an outer diameter surface of the casing hanger so that the seal ring prevents flow through the annulus. A nose ring is secured to a lower end of the seal ring so that, when the seal ring is energized, a conical surface of the nose ring engages a mating conical profile formed in the inner diameter surface portion of the wellhead and the nose ring engages a surface opposite the conical surface with a substantially smooth outer diameter surface portion of the casing hanger to limit upwards axial movement of the casing hanger.

主权项

1. A wellhead assembly comprising:
A wellhead member defining a bore having a shoulder, the bore having a conical profile that decreases in diameter in an upward direction; A hanger landed on the shoulder within the bore of the wellhead member and defining an annulus between the wellhead member and the hanger; A hanger seal ring for disposal within the annulus, and for engagement with an inner surface of the wellhead member, and an outer surface of the hanger so that the hanger seal ring prevents flow through the annulus; and A nose ring having first and second ring components, the nose ring for attachment to a lower end of the hanger seal ring, the first ring component having a conical surface for engagement with the conical profile in the bore of the wellhead member, and the second ring component for engagement with the hanger to limit upward axial movement of the hanger; Wherein the first and second ring components are rigidly attached one to another by a shear element prior to engagement with the hanger and the conical profile in the bore of the wellhead member.