Riser for connecting sub-marine wellhead to floating drilling support, has connection and/or disconnection unit formed at base, where closing unit closes interior space of riser that is adapted to control draining fluid contained in space

摘要

The riser (1) has a connection and/or disconnection unit formed at a base (8), where a closing unit (11) closes an interior space of the riser that is adapted for controlling draining fluid contained in the space. The closing unit is hydraulically connected from a surface. The closing unit is constituted by a well obturator i.e. annular obturator, so as to maintain the well obturator at hydraulic pressure exerted from top towards bottom. A lower marine riser package (LMRP) is fixed on a base of a floating support by an intermediary tension unit. An independent claim is also included for a riser disconnection method.