Qualification of Subsea Thermal Insulation for Extreme Temperatures

The Kristin field in the Norwegian Sea have a flowing wellhead temperature of 162 °C. This is believed to be the maximum temperature for an insulated subsea wellhead experienced to date. An extensive qualification program for the corrosion coating and thermal insulation was performed including accelerated ageing in water at elevated temperatures. The most critical test was the insulated hot plate test with holes down to the steel surface. For the extreme temperature of 162 °C a phenolic syntactic foam system showed the “least worse” results, and was chosen as the insulation system.