Continuous Trawl Protection of Heating Cable for Direct Electric Heating of Flowlines

The following paper describes the experimental and analytical work that was carried out in the development of a continuous external trawling protection for the Direct Electrical Heating cables for the subsea flowlines on the Kristin Field in the North Sea. The developed trawl protection was able to absorb the required 5.0 kJ energy without damage to the cable. The Kristin field is the most extreme HP/HT subsea field developed in Norway to date (170 degC reservoir temperature and 911 barg pressure). This is the first time that a continuous trawl protection is applied to the full length of a flowline. The normal approach would be burying to avoid interaction with fishing activities, however since this is a HP/HT subsea flowline it was necessary with an extra cooling from unburied pipelines to reduce the riser temperatures.