Damage to offshore production facilities by corrosive microbial biofilms

In offshore production facilities, large amounts of deaeratedseawater are continuously injected to maintain pressure in oil reservoirs and equivalent volumes of fluids, composed of an oil/gas, and water mixture are produced. This process, brewing billions of liters of biphasic fluids particularly rich in microorganisms, goes through complex steel pipeline networks that are particularly prone to biofilmformation. Consequently, offshore facilities are frequently victims of severe microbiologicallyinfluenced corrosion. Understanding of microbiologicallyinfluenced corrosionis constantly growing. In the laboratory, the inventory of potentially corrosivemicroorganisms is increasing and microbial biochemical and bioelectrical processes are now recognized to be involved in corrosion. However, understanding of corrosivemultispecies biofilmsand the complex metabolic processes associated with corrosionremains a considerable challenge as simple laboratory biofilmscomprising pure or defined mixed cultures poorly represent the complexity of in situ biofilms. Complementary, antagonistic, and parallel microbial pathways occur within the complex microbial and inorganic matrix of the biofilmswhich can lead to high corrosionrates. This mini-review explores models of microbiologicallyinfluenced corrosionand places them in the context of the multispecies biofilmsobserved in situ. Consequences of mitigation strategies on biofilm corrosivenessand dispersal are also discussed.