Patent ID: 9303480
Filing Date: 2016-04-05
CPC Classification: E21B

Claim Text:
1. A system for coupling a platform to a subsea wellhead comprising: a riser extending between the platform and the subsea wellhead, wherein the riser comprises an inner riser and an outer riser; an inner drilling riser tie-back connector (“ITBC”) having a main body, wherein the ITBC is coupled to the inner riser, wherein the ITBC further comprises a locking ring operable to engage a groove in an internal bore of the subsea wellhead; a seal assembly disposed at an interface directly between the internal bore of the subsea wellhead and an external wall of the main body, wherein the seal assembly is disposed uphole relative to the locking ring; and a ratch latch threaded ring disposed within the ITBC, wherein the ratch latch threaded ring is movable downhole along a no-go sleeve disposed against the internal bore of the subsea wellhead.