Microbiologically influenced corrosion and community dynamics of oil-well produced water at different temperatures

Microbiologically influenced corrosion (MIC) is a universal issue of significant concern in the petroleum industry, with the potential for enormous economic losses and casualties. This study focused on the effect of temperature on MIC and the corrosion mechanism. The corrosion rate, morphology, corrosion products, and microbial community composition of produced fluid samples from the Zhanjiang oilfield were measured after anaerobic culture at 30 and 60 °C for 14 days. The corrosion rate of the Z1 and Z2 samples decreased with increasing temperature, while the corrosion rate of the Z3 sample changed from light corrosion to heavy corrosion. The Z1 sample was dominated by pitting corrosion, the Z2 sample had a relatively smooth surface, and the Z3 sample was observed to have one dimensional wormhole corrosion at 60 °C. The microbial community composition by 16S ribosomal deoxyribonucleic acid (rDNA) sequence showed that the bacterial communities were dominated by Pseudomonas and Bacillus, and the archaeal communities were mainly composed of Methanothermobacter, Methanosaeta, and Candidatus Nitrosotenuis, which was prevalent in Z3 samples at 60 °C. It suggested that MIC could be caused by extracellular electron transfer and reduction of nitrate or nitrite to N2 and NH4+ by bacteria, and utilization of CO2 to produce CH4 by archaea. Overall, the results of this study can provide comprehensive data and new insights into corrosion management strategies for oil fields.