Bacterial Corrosion of Offshore Structures^★ Available to Purchase

Reports published by the British Admiralty and by individuals in England and the United States, show that sulfate-reducing bacteria can cause corrosion of iron under some conditions. Because of the importance of maintaining in good condition the steel piling of offshore structures in the Gulf of Mexico a research investigation of the possibility of bacterial corrosion of these installations was inaugurated. Laboratory tests were directed toward developing fairly pure cultures of sulfate-reducing bacteria and using them in both natural muds and synthetic culture media for the purpose of determining their effect on the corrosion rate of steel coupons under anaerobic conditions. Maximum corrosion rates obtained were of the order of 0.001 inch per year. Several assemblies of twenty coupons each were installed at a marine platform approximately seven miles off Grand Isle, Louisiana; the coupons on each assembly were spaced to extend a few feet above and a few feet below the mud line. Somewhat similar assemblies were installed immediately offshore at Barbour’s Cut, near La Porte, Texas, and at the Crash-Boat Basin at Galveston, Texas. Results of the study show that the corrosion rate due to bacterial action is low, and that cathodic protection is a sufficient safeguard against bacterial corrosion.