Conference article

Direct electrical heating (DEH) is a technology for preventing hydrate formation and wax deposit in oil and gas pipelines. Nexans Norway AS is currently researching and developing deep-water DEH solutions. A Nexans research project which was finished in year 2014 concludes that a deep-water DEH riser cable for 2 300 m water depth is feasible. This paper presents an iterative algorithm for torsion balancing deep-water cables and umbilicals, using analytical considerations of the armor wires. The main advantage of this algorithm is that it does not depend on analytical expressions of the cable’s torsion balance. Hence, the algorithm can be used also on cables which mechanical properties are established using finite element simulations, i.e. not only on cables where there exist analytical models of the mechanical properties. The algorithm was initially developed for the deep- water DEH riser cable. The algorithm works very well. After two iterations the torsion unbalance was reduced by 98%.

Cross Section Analysis; Deep-Water; DEH; Direct Electrical Heating; Offshore Technology; Subsea Cable; Torsion Balancing; Umbilical