Abstract
Microbiological risk evaluation of topside systems of four floating production storage and offloading in West Africa was carried out over a period of four years. Field samples were taken, and DNA analyzed using next-generation sequencing technology to identify and classify the microbial population present on the facilities. Several classes of bacteria and archaea were sequenced and identified from the samples, including those that have been shown to play key roles in biofouling, microbiologically influenced corrosion and biogenic hydrogen sulphide generation in oil and gas production systems. The classic microbial population according to metabolic classes associated with oil and gas production systems were identified. The study found that of the 137 microbial genera identified, 45.3% were associated with biofouling, 29.9% with microbiologically influenced corrosion, 29.1% with a H2S/MIC risk and a 2.9% population did not have a clear link to any of these risks. There was at least 98% relative abundance of bacteria population in the samples from all FPSOs, implying a significant exposure to the risks posed by microbial growth and proliferation.
