Modelling of Complex DEH Systems

Direct Electric Heating (DEH) is an increasingly attractive method for flow assurance that has been in use for more than 15 years. All current systems in operation consist of a single flowline or have subsea architecture such that interaction between systems as well as components in the proximity is limited. DEH is selected as flow assurance for two ongoing field developments where the layout is such that there will be interaction with other subsea architecture. One system has numerous flowline systems in close interaction and the other has unfavorable crossing. This paper presents some of the design aspects which do arise for fields where the flowlines are in close proximity to each other. The paper also discusses how to handle interference with existing infrastructure when installing DEH in a complex field layout. The aspects studied are effect on power rating, ac corrosion and thermal rating of cables and flowlines.