This case was a 54 km long 32’ export gas pipeline in the North Sea, with severe scouring issues. Installation campaigns were executed both 5 years after as-laid (when 71 spans were intervened on) and 10 years after as-laid (when 192 spans were intervened on). Additionally, there had been 11 surveys in 14 years of the pipelines lifetime, which, with the new analysis, had the potential of being reduced.
DNV GL solution
Estimating remaining fatigue capacity using Global Free Span service showed that the free span intervention campaigns previously carried out were unnecessary.
Outcome and benefits
In total, the new analysis from the Global Free Span service demonstrated a potential cost savings of 1.9-2.6 Million USD.