Adjustable Riser Suspension System

摘要

A riser suspension system for suspending a riser from a subsea wellhead housing using a running tool. The system comprises a surface wellhead housing, a riser hanger and a load shoulder. The surface wellhead housing comprises a bore, a shoulder profile, a lock profile and a support ring. The riser hanger assembly comprises a hanger body, an adjustable suspension mechanism rotationally coupled with the hanger body and a lock ring expandable into engagement with the lock profile. The load shoulder assembly couples with the riser hanger assembly and comprises a lock ring expandable into engagement with the shoulder profile. The invention further claims a multi-function running tool that requires only a single trip and which can manipulate, latch and back up a tie-back adapter into the downhole equipment and provide positive preloaded, locked-in, tension of the riser.

主权项

1. A system for tying back a riser under tension from a platform to a subsea wellhead housing using a running tool, comprising:
a surface wellhead housing comprising a bore; a riser hanger assembly installable in the bore and comprising:
a hanger body to support the riser; andan adjustable suspension mechanism coupled with the hanger body; a load shoulder assembly releasably coupled with the riser hanger assembly and comprising a load shoulder, the load shoulder assembly being releasable from the riser hanger assembly and lockable to the wellhead housing inside the bore using force from the riser hanger assembly; and wherein the adjustable suspension mechanism is axially adjustable relative to the hanger body to engage the load shoulder and support the riser hanger with the riser in tension.