AMPP O-CAT case studies
AMPP O-CAT · Put your knowledge to work in context.
The AMPP Offshore Corrosion Assessment Training (O-CAT) is a corrosion-assessment credential offered within the education and certification portfolio of AMPP - The Association for Materials Protection and Performance, which describes itself as the largest global community for corrosion and coatings expertise. O-CAT is aimed at personnel who evaluate the condition of offshore structures and their protective systems, where corrosion control decisions carry direct safety and integrity consequences. The AMPP O-CAT case studies are 5 cases and about 2,992 words.
1Splash-Zone Riser Coating Failure and CP Shadowing
A 24-inch production riser on a fixed jacket in the Gulf of Mexico has a three-coat epoxy/polyurethane system specified at 350 µm DFT. At the 18-month inspection, the splash zone (roughly +3.0 m to +6.0 m above mean sea level) shows blistering over ~15% of the area, with rust bleeding at the blister edges.
572 words, about 3 min2Anode Depletion on a Jacket Leg Below the Mudline
A four-leg jacket installed in 1987 in 110 m of water uses aluminum-indium sacrificial anodes. A 2023 CP survey reports structure-to-electrolyte potentials of -0.78 V versus Ag/AgCl/seawater at the -20 m elevation and -0.82 V at -60 m, both more positive than the -0.90 V criterion.
690 words, about 3 min3Coating Repair Strategy for a Corroded Deck Under a Tight Window
A production deck on an offshore platform has a zinc-rich primer / epoxy midcoat / polyurethane topcoat system that is 12 years old. A condition survey rates the deck at ASTM D610 rust grade 6 (about 0.3% rust) overall, but flags isolated areas of grade 4 (about 3% rust) around weld toes, handrail bases, and drain penetrations.
568 words, about 3 min4Interpreting a CP Survey with Stray Current and Reference Electrode Drift
A pipeline riser and its subsea spool are protected by a combination of sacrificial anodes and an impressed-current system. A survey conducted from a vessel reports potentials along the riser that vary from -1.05 V near the top to -0.65 V at the spool tie-in.
603 words, about 3 min5Fitness-for-Service Decision on a Corroded Brace
An ultrasonic inspection of a diagonal brace on an aging jacket finds external wall loss at a weld toe. The brace is 610 mm OD with a nominal wall of 19 mm.
559 words, about 3 min