Abstract
Direct electrical heating (DEH) is a field proven flow assurance technology for subsea flowlines. In this paper, challenges and opportunities of onshore direct electrical systems are evaluated. Onshore DEH is found to be feasible and behave similarly to regular subsea DEH. Design parameters, such as the thermal resistivity of soils, flowline burial depth and ambient temperature may have wide windows for operation along the flowline length and over time. To design the system, these design parameters must be established and kept within reasonable limits. It is recommended to design the piggyback cable with a semi-conductive jacket for reliability. The anode performance in soils under alternating currents is unknown and needs further attention.