SURFACE PLATFORM FOR USE WITH SURFACE BOPS AND HIGH-PRESSURE RISERS

摘要

A mudline closure device is lowered between tensioners coupled to a deck of a vessel or rig onto a subsea wellhead. A tensioner platform is then attached to the tensioners. The tensioner platform includes a platform opening having an inner diameter through which an emergency disconnect system may pass. The tensioner platform also includes rotation bearings secured in the platform opening. A split support includes outer surfaces disposed along its circumference. The outer surfaces are seated on the rotation bearings. The split support includes a support opening having an inner diameter through which a marine riser may pass. The split support also includes a landing shoulder secured in the support opening to suspend a surface blowout preventer to the deck. As the vessel or rig changes direction, the split support rotates relative to the tensioner platform without imparting excessive torsion on the marine riser.