SUBSEA HYDROCARBON FLOWLINE SYSTEM AND RELATED METHOD AND USE

A subsea hydrocarbon flowline system (300) is disclosed. The flowline system has a hydrocarbon flowline (302); an electric trace heating system (304) arranged along at least a part-length of the flowline to control the temperature of hydrocarbon fluid flowing in the flowline; and a power input connector (Pin) configured for receiving electrical power from an electrical power providing system for powering the electric trace heating system. The electric trace heating system has a first three-phase trace heating cable (C′) and a second three-phase trace heating cable (C″), each trace heating cable extending between the power input connector and a cable termination (T′; T″) where phase conduits (L1′, L2′, L3′; L1″, L2″, L3″) of the trace heating cable are Y-connected and terminate in a neutral connection point (LN′; LN″). Further, the flowline system has a power output connector (Pout) for providing electrical power to a subsea hydrocarbon production system; a first electrical conduit (306′) extending between the neutral connection point of the cable termination of the first trace heating cable and the power output connector; and a second electrical conduit (306″) extending between the neutral connection point of the cable termination of the second trace heating cable and the power output connector, wherein the first and the second electrical conduits are electrically accessible at the power output connector for powering the subsea hydrocarbon production system.