FPSO Hull Corrosion Management to Minimize Operational Down-Time Due to Artificial Metocean Conditions: A Thermal Approach

It is common to find a less than 3% coating breakdown in the first 2 to 3 years of operation among FPSOs operating world-wide having hulls with conventional coatings (Cc). Two different coatings S1 and S2 formulated from an aggregate of paints shall be investigated along-side the conventional coating by means of factorial experiment, pull test, GCMS and Holiday test in order to ascertain the superiority of S1 and S2 to Cc. Thermal radiation values of 3.9Kw/m2 and 4.1Kw/m2 were simulated from two flare stacks operating at 3.5 bara and 1.5 bara respectively using DNV PHAST software. Temperature conversions from these thermal radiation values using Stefan Boltzman’s equation yielded 123.850C and 102.430C. These temperatures, salinity of 55.25ppt and Ph of 7.52 will be combined to treat twenty-four (24) carbon steel coupons coated with the three coatings. The main effects from the factorial experiment and the pull test will be reported. Gas Chromatography Mass Spectrometry will be used to study the degradation of the coating layers over time of immersion in the saline environment at the different temperatures123.85 0C and 102.43 0C while Holiday test will be conducted to determine any discontinuity in the coatings. The ability of S1 and S2 to overcome the 3% coating breakdown problem will be examined using ANOVA and the best option adopted as FPSO coating against corrosion in saline environment under elevated temperature.