In order to determine the degree and type of corrosion that seawater would cause on carbon steel piping when laid- up for a period of approximately three months and the effects of various corrosion mitigation treatments, simple immersion tests of corrosion coupons were performed in the laboratory over a period of 90 days. Seawater collected from the Gulf of Mexico was treated by chemical (oxygen scavenger & biocides) and/or physical (filtration) methods as a means to mitigate uniform corrosion and localized attack, including microbiologically influenced corrosion (MIC). Microbiological and chemical analyses of the seawater were performed as were metallurgical analyses of the coupons using light microscopy, scanning electron microscopy (SEM), and corrosion rate measurements. Under the conditions tested, no MIC-type pitting could be detected, uniform (etching) attack was the predominant corrosion observed, and treatment of
filtered seawater with oxygen scavenger yielded the best results.