Application of Molecular Microbiology Techniques as Tools for Monitoring Oil Field Bacteria

Abstract

Abstract For the past forty years, the oil industry has relied on two recommended standard practices (API RP-38 and NACE TM0194), which provide guidance on how field samples should be collected, analysed and results interpreted. Both documents highlight the enumeration of viable bacteria by culture techniques as the standard method for routine monitoring and anomaly investigation. API RP-38 has now been withdrawn. Within the appendices of TM0194 the possible availability of molecular microbiology techniques is mentioned, but no detailed guidance or standard method for the application of any of the molecular tools is currently available. As the application of molecular tools in environmental microbiology is developing rapidly, it is clear that a wide range of analyses are now available as potential tools to at last reveal ‘mysteries’ such as the complex metabolic processes causing the problems of microbial influenced corrosion (MIC), persistence in the presence of biocides and the souring of reservoirs during seawater flooding. However, these methods must be applied with caution. Whilst they undoubtedly offer the potential of huge strides forward in our understanding of oil field bacteria communities, there are no ‘off the shelf’ solutions and standardised methods will ultimately be required if comparative data are to be generated across the industry. This paper presents a summary of the benefits and drawbacks of some of the most commonly quoted molecular microbiology techniques together (where available) with examples of their application to field samples.