Abstract
Direct Electrical Heating (DEH) is a field-proven technology for hydrate and wax management of subsea production pipelines. DEH has been in use for nearly 20 years and is installed on approximately 30 pipelines/flowlines with length up to 43 km and on 1000 m depth, Studies indicate significant cost-reductions and improved utility by going from the present DEH-systems operating at normal power frequency of 50/60 Hz to a system operating at a frequency ranging between 100 and 200 Hz. Increased frequency reduces the size and weight of the cables, reduces electrical currents in seawater, reduces AC corrosion and is favourable regarding development of ultra-deep fields as well as continuous operation. Copyright © 2018 by the International Society of Offshore and Polar Engineers (ISOPE)