Microbial monitoring is an essential step towards safeguarding your assets against the effects of corrosion, and allows you to assess the likelihood of reservoir souring.
At NCIMB, our experienced microbiologists can use a number of complementary techniques for the microbial analysis of samples from oil and gas facilities, and supply media test kits for customers who want to undertake their own testing.
Microbially influenced corrosion
Some groups of microorganisms that are commonly occurring in the environment can cause serious problems in an industrial setting. For example, the proliferation of sulphate reducing prokaryotes (SRP) can influence corrosion rates in pipelines, vessels and machinery, and the conditions found within production facilities can provide the ideal environment for their growth.
The actions of different groups of microorganisms influence corrosion in different ways. For example growth of some groups of microbes can create conditions that allow proliferation of others, which in turn produce corrosive waste products such as hydrogen sulphide or acids.
Monitoring for the presence of the key groups of microorganisms known to influence corrosion in oilfield environments, allows remedial action to be taken if numbers start to rise. Continued regular monitoring can also determine the efficacy of steps taken to control these groups of organisms, helping you to make informed and timely decisions.
At NCIMB we can identify and quantify microorganisms known to influence corrosion using both the latest molecular methods, and traditional culture-based techniques. Analysis can be undertaken on most types of liquid and solid sample, including production fluids, scales, pig wax and NORM contaminated corrosion coupons. We also offer analysis of the whole microbial community within the reservoir.
- qPCR: This technique is used to quantify groups of microorganisms without any requirement for growth. It therefore gives very rapid results, and ensures that microbes that do not grow under laboratory conditions are included in counts.
- Culture-based enumeration of:
- General heterotrophic bacteria
- Acid producing general heterotrophic bacteria
- Sulphate reducing bacteria (mesophilic, thermophilic and hyperthermophilic)
- Nitrate reducing bacteria
- Next-generation sequencing (metagenomics): This technique, which has revolutionised understanding of environmental microbiology in recent years, analyses the whole microbial population from a single sample. It identifies the groups of microorganisms present to give a comprehensive picture of the microbial ecosystem within the oilfield. This allows microbiological changes to be monitored in longitudinal studies as well as aiding understanding of the functional impact of the species observed. 16S community analysis is a powerful tool that can help operating companies assess the likelihood of reservoir souring and corrosion.
- NORM contaminated coupons: we can accept NORM contaminated coupons and can undertake microbial analysis as well as reporting on the NORM levels.
- NCIMB partners with corrosion monitoring specialists ICR: in the delivery of full microbiological audits and surveys of production facilities. Analysis of samples from retrieved corrosion coupons and probes allows sessile microbial growth on pipework and in vessels to be monitored. This data allows a more accurate evaluation on the threat of microbially influenced corrosion than monitoring planktonic populations alone. For more information about ICR's comprehensive corrosion monitoring and microbiological audit services visit their website.
We can advise on the most appropriate approach to monitoring and have participated in R&D projects as well as undertaking routine analysis.
We supply media kits for quantification of:
- Sulphate reducing bacteria
- General heterotrophic bacteria/acid producing general heterotrophic bacteria
- Nitrate reducing bacteria
We can also prepare other types of media on request, and store stocks of specific media for customers.
We can undertake lab-based biocide testing against our own in-house North Sea microbial consortium, or enrich from clients’ own samples for laboratory testing. We can also undertake direct enumeration from customer samples following treatment at the production facility to determine efficacy in situ.
We can use both traditional culture-based enumeration for determining the efficacy of biocides or take a molecular approach with qPCR. Culture based enumeration is likely to be the most appropriate approach for testing against lab-grown cultures, whereas qPCR can give faster results for testing the impact of biocides following on site treatment, as part of a longer term study.
For customers seeking more in depth understanding of the whole microbial community, we can undertake nextgeneration sequencing providing detailed metagenomic information on the microbes present, and their relative abundance. This information can then be used as part of an ongoing monitoring regime.