Molecular Biology Identifies Troublesome Microbes and Aids Effective Control Actions

Abstract

Molecular Microbiology Identifies Troublesome Microbes and Aids Effective Control Actions

Oil and gas production, transport, storage and refining have always suffered from microbial actions, most notably from sulphate-reducing bacteria (SRB) which may generate hydrogen sulphide(H2S), and so give corrosion, blocking and safety problems. Control of SRB is routinely attempted by injecting organic and/or inorganic biocides, but often with limited success, which is often because conventional bacterial monitoring techniques are very selective and greatly underestimate the real numbers of microbes present in any system.

This presentation will outline molecular microbiology techniques recently available for use in oilfields, which give much more detailed and accurate quantification on microbial populations. A case history in a Middle East oilfield will be briefly described, in which the water injection system uses mixed aquifer and produced waters, and was experiencing heavy biofouling and very poor quality water. The biocides in use were ineffective and the study showed that this was due to high concentrations of unexpected microbes, resistant to those biocides. Subsequent system cleaning and a new biocide regime have solved the problems.