Method and apparatus for disconnecting and retrieving multiple risers attached to a floating vessel

摘要

A riser buoy (36) supports a plurality of risers (19) and is releasably docked within a generally cylindrical turret (20) of a floating storage vessel (10) at a location above the sea level (12) to provide dry access to quick disconnect/connect mating couplings (32, 40) on the turret (20) and riser buoy (36). A weight (58) connected by anchor chain (44) to riser buoy (36) is connected at its upper end to a retrieval line (60) which is controlled by a winch (62). Riser buoy (36) upon disconnection from vessel (10) is positioned at a predetermined submerged water depth below tanker traffic and high wave loads. Riser buoy (36) is docked within turret (20) independently of positioning means such as anchor chains (17) between the sea bed and the turret, or a thrusting positioning system including thrusters (16) of the vessel.