Evaluation of sulfovibrio vulgaris adherence on three different polymeric coatings

Abstract

Microbiological Induced Corrosion is a big concern in oil and gas market, mainly in water injectors and disposal wells in which the alternatives of candidate materials are CRA´s with very high PREN (Pitting Resistance Equivalent Number) or coated carbon steel. Organic coatings are used on the tube internal surface to prevent corrosion problems in service. The failure mechanism of these coatings in MIC environments is not well understood. In this study three different types of polymeric coatings were evaluated. Small coated samples were prepared in laboratory and were exposed to Desulfovibrio vulgaris bacterium in Postgate´s C culture medium (initial number of bacteria 106 bacteria/ml). Samples of bare L-80 steel and Cr13 stainless steel were also exposed. Flasks were incubated under anaerobic conditions for 14 days. After one week of exposure, the medium was renewed, replacing half of the exhausted medium with an equal volume of fresh medium. After 14 days, the biofilm development was evaluated using Scanning Electron Microscopy. Tested samples were characterized using FTIR, adhesion tests, color and gloss were measured.