Offloading arrangements and method for spread moored FPSOs

摘要

A mooring arrangement between a floating storage body spread moored in deep water and a shuttle tanker, the arrangement including a single point buoyant member that is adapted for mooring a shuttle tanker in offloading position relative to a floating production, storage and offloading vessel (FPSO) with a link between the floating storage body and the single point buoyant member. One embodiment (100) of the invention employs a submerged yoke (30), having one end (31) rotatably coupled to a FPSO (10) and a second end (32), supported by a buoy. A mooring hawser (28) extends from the buoy to the shuttle tanker and product hoses connect the shuttle tanker with the FPSO and extend along the submerged yoke. In another embodiment, the mooring buoy is stationed by a hold-back mooring system (303–304) and the FPSO or the tanker or both is provide with traction device (308) to move the tanker into loading position with respect to the FPSO. Other embodiments of the invention establish mooring of a shuttle tanker so that it can weathervane 360 degrees during offloading activity. In another embodiment, the mooring buoy (600) is provided with a dynamic positioning system (614) for controlling shuttle tanker positioning with respect to conditions of the environment or for moving the tanker to a desired position during loading.