AN OFFSHORE PROCESS VESSEL AND A METHOD OF OPERATING SAME TO RECEIVE OIL AND/OR GAS PRODUCTION FROM A SUBSEA WELL

摘要

An offshore process vessel is described for connecting service and production hoses to a deepwater production riser system and for performing subsea maintenance thereon without major equipment support. The vessel has a pair of longitudinally aligned moonpools, a derrick above the forward moonpool, a rotary powered turret within the aft moonpool, and tension-maintaining assemblies for terminal hoses in combination with a rotary fluid transfer system for transferring production fluids, electrical power, hydraulic power, and control signals across a rotating interface between the vessel and a flowline bundle of the service and production hoses. The turret supports a coaxially disposed and selectively ejectable plug through which the service and production hoses pass. These hoses are joined together in a linear array along the length of the flowline bundle which hangs as a catenary from the plug while being attached to the riser system. Above the plug, the terminal hoses and the service and production hoses are connected by rigid piping. The tension maintaining assemblies keep the terminal hoses at constant length as the vessel weathervanes on station through at least 270 DEG above the riser system and around the turret. The vessel additionally has a plurality of hose reels and wire winches for assembling the service and production hoses into the flowline bundle as a sling between the moonpools and below the vessel. The winches also enable the flowline bundle to be disconnected at its inlet end from the service moonpool and to be connected to the riser system.