Direct Electrical Heating (DEH) Subsea Flowline Calculator
Model single-phase 50/60 Hz AC power delivery, current division between pipeline and seawater, and active heating duty (W/m) to prevent hydrate plugs.
Pipeline & Electrical System Parameters
DEH Power & Sizing Results
Direct Electrical Heating (DEH) Architecture
Direct Electrical Heating is an advanced flow assurance system that prevents hydrate and wax deposition in long subsea tiebacks during unplanned production shutdowns. A single-phase AC current is driven down a piggyback cable strapped to the insulated pipeline and connected to the pipe steel at the far-end subsea template.
Current Division & Skin Effect
The return current naturally splits between the conductive carbon steel pipeline shell (typically 55% to 65%) and the surrounding seawater (35% to 45%). At 50/60 Hz, the ferromagnetic nature of steel concentrates current in an outer skin layer of only 1 to 3 mm, substantially increasing the effective AC resistance and generating Joule heat ($P = I^2 R$).