FPSO (Petrojarl/Sevan/circular)

FPSO designs split into two hull families. The ship-shaped FPSO, of which Teekay’s Petrojarl series is the established North Sea example, uses a tanker-form hull weathervaning on a turret mooring so the bow heads into weather. The Sevan design instead uses a cylindrical hull with no turret or swivel: its circular plan-form has no preferred heading, so it sits on fixed catenary moorings with risers led through a central moonpool. Sevan Piranema was the first circular FPSO; the Sevan 300 hull also produced units such as Petrojarl Kong (ex Voyageur Spirit). The cylinder trades higher motions in some seas for simpler mooring and large deck and storage capacity.