Abstract
Hydrocarbon transporting pipelines and seawater injection networks are subject to many different corrosion deterioration mechanisms, one of which is microbiologically influenced corrosion (MIC). MIC is caused by a wide range of microorganisms that naturally thrive in the oil reservoirs and associated secondary seawater injection systems. To gain insight into the impact of microbes on corrosion in oil and sea water injection pipelines, the microbial diversity of corrosion product samples collected from a sour oil pipeline and a seawater injection pipeline were evaluated. As cultivation-based methodologies can greatly underestimate the microbial diversity associated with an environment, the microbial populations of sour crude oil and seawater pipeline samples were evaluated with a 16S rRNA gene pyrosequencing approach. The sequence results indicate that the microbial communities in the corrosion products obtained from both the sour oil pipeline and seawater pipeline were dominated by bacteria; though archaeal sequences (predominately Methanobacteriales) were also identified in the sour sample. For the sour sample, the dominant phylotypes include members of the Synergistales, Thermoanaerobacterales and Syntrophobacterales; while for the seawater injection sample, the dominant phylotypes include members of the Rhodobacterales, Flavobacteriales, Kiloniellales and Desulfovibrionales. This paper discusses the microbial diversity of the collected samples and their potential contribution to MIC for both systems.
