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Long Term Qualification of XLPE Electrical Insulation Systems for Offshore Deep Water Cables


There is an increasing demand for subsea electrical
power transmission in the oil- and gas industry. Electrical
power is mainly required for subsea pumps, compressors
and for direct electrical heating of flowlines. The majority
of subsea processing equipment is installed at water
depths less than 1000 meters. However, projects located
offshore Africa, Brazil and in the Gulf of Mexico water
depths of 3000 meters are reported.
Hence, Nexans and SINTEF Energy Research initiated a
long term development program to qualify deep water
XLPE power cable. The long term test program was
mainly based on ANSI / ICEA S-97-682-2007. Some
adjustments related to the high hydrostatic test pressure
(300 bars) were; however, required.
A 7.2 kV XLPE test cable was manufactured and installed
in a large hydrostatic test vessel at 45 °C and 310 bars.
The cable samples were stressed with an electrical test
voltage of 17 kV; corresponding to an average electrical
stress of 5.9 kV/mm.
Evaluations are performed after 120, 180, 360 and 900
days of hyperbaric ageing.
Nexans has a long and proven experience of delivering
wet designed power cables i.e. without a metallic water
barrier. After the hydrostatic ageing of the model cable at
310 bar hydrostatic pressure the cables were tested in
order to determine the electrical properties of the
insulation system. In addition, water tree analyses were
performed after the hydrostatic ageing


Academic chapter/article/Conference paper





  • SINTEF Energy Research / Elkraftteknologi
  • Nexans Norway AS






Jicable'15 - 9th International Conference on Power Insulated Cables : proceedings



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