Caisson corrosion protection 

August 2019Major North Sea OperatorOnshore Aberdeen

ICR were engaged to provide a engineered composite repair solution on a produced water caisson prior to installation offshore. The previous caisson was corroded due to wave action causing thermal cycling. 


Two new sections of a 12” caisson were fabricated and sprayed with an internal coating prior to ICR applying the composite solution. It was a design requirement that surface preparation to Sa2.5 and was achieved prior to the application of 4 layers of Technowrap™ 2K using HT (High Teemperature) resin. 

These were then welded together and an angular profile of 45μ was achieved using bristle blasters. A composite wrap was then applied to cover the welded section. Heat blankets were used througout the process to assist curing. 

Design Temperature100°C
Design Pressure2.5bar
Material GradeSuper Duplex
Surface PreparationSa2.5

The change in temperature was taken into consideration by derating the allowable strains in line with ISO 24817.

Results & Benefits
  • ICR technicians worked day and night for a total of 7 days to complete the repair 
  • A repair lifetime of 20 years was given 
  • The solution will prevent future corrosion due to thermal cycling, maintaining the integrity of the structure