Archaea and the Use of Molecular Microbiological Tools for Monitoring and Control of Microbiologically Influenced Corrosion (MIC) in Pipelines
MIC is estimated to result annually in billions of dollars of damage to oil and gas pipelines world-wide. Although much work has been conducted identifying the principal bacteria involved in MIC, the importance of archaea, notably sulphate-reducing archaea (SRA) and methanogens in MIC, has only recently been understood. Little work has been carried out investigating the efficacy of traditional MIC mitigation strategies, such as biocide application, on archaea. However, it is logical that archaea are more resistant to biocidal action due to their complex cell membrane composition. The resistance of archaea to biocides will be discussed.
A well managed biocide regime can greatly reduce the risk of MIC and help maintain pipeline integrity; however it is crucial that appropriate microbial monitoring programmes are in place. The drawbacks of conventional microbiological monitoring (using culture-based techniques) are well known. Molecular microbiological techniques are now ubiquitous in other industries but have yet to be fully integrated into the oil and gas industry. Novel monitoring techniques robust enough for on-site use will be discussed. The technologies should be quick, easy to use and add real value by allowing informed decisions to be made regarding issues such as biocide efficacy, but molecular microbiological techniques require extensive field trials.