Oilfield Microbiology: Case Study of Molecular Techniques for Determining the Risk of Microbiologically Influenced Corrosion MIC

The objective of this paper is to explain the beneficial information obtained during a microbiological study of an oilfield survey, where molecular microbiology techniques where utilised. The inclusion of these techniques highlighted information that would have otherwise been missed and/or misinterpreted. The molecular microbiology techniques deployed during this survey included Quantitative Polymerase Chain Reaction (qPCR) and Next Generation Sequencing (NGS). The aim of PCR technology is to specifically increase a target (gene) from an undetectable amount of starting material. The first step is extraction of DNA from the sample, which will subsequently be subjected to the qPCR technology. During qPCR gene copies are made during thermocycling and a fluorescent marker accumulates, which can be used to quantify the target gene. Similar to the PCR technology, DNA is extracted from the sample and the DNA is amplified. In NGS, this is then sorted into a library of small DNA segments before they are amplified. During the sequencing step each DNA fragment amplified is sequentially identified from light signals emitted by comparing with a DNA library. The results obtained indicated crucial additional information that was not detected by traditional methods. In addition to much higher, truer quantification of known populations of Total Prokaryotes and Sulphate Reducing Prokaryotes, identification of other groups of DNA was possible through the NGS technique analysis. The results provided valuable information, which has subsequently been used to apply successful, targeted mitigation strategies to reduce the risk of MIC to assets.