Sept. 21, 2011
-- In addition, MIC has the capability of reducing the service life span of pipelines by a typical factor of 15%. MIC has been observed as one of the major causes of underground pipeline corrosion.
Sulphate reducing bacteria (SRB) have been reported to be responsible for extensive corrosion in hydrocarbon industry. SRB can not only attack utility systems (even with added biocide) but also gas and oil pipelines. While SRB are the most studied class of corrosion enhancing micro-organisms, there are other classes of micro-organisms that can affect corrosion rates. There are other types of corrosion-enhancing bacteria such as iron-reducing bacteria, iron-oxidizing bacteria, nitrifying bacteria, methanogenic bacteria and so on.
Almost all known engineering materials (from carbon steel to stainless and duplex stainless steels and also non-ferrous metals such as copper alloys and non-metals such as some polymers and concrete) are susceptible to MIC. In the presence of corrosion-related bacteria, steel can experience corrosion rates from about 1mm/yr to extreme cases of 10 mm/yr.
Detrimental impacts of MIC can be enhanced through “inappropriate”
practice of welding, hydrostatic testing and material/coating selection. Traditional mitigation strategies to reduce the impact of corrosion can be classified as physical (such as pigging) and chemical (use of biocides). There are also some new technologies that may assist mitigation. These technologies are basically based on using certain biological technologies (such as use of “good” bacteria against corrosion-related bacteria). These methods are still new and although they have been employed in some industrial situations, they are still far from commercialized applications.
Dr Reza Javaherdashti is a researcher-consultant of corrosion and especially MIC. He has authored more than 40 peer-reviewed papers as well as the same number of root cause analysis reports for industries on corrosion and MIC . He has authored three books on MIC including “Microbiologically Influenced Corrosion-An Engineering Insight”(published by Springer, UK, 2008).
You can learn more about new MIC Prevetion and Mitigation Methods by attending Microbial Corrosion Masterclass, where the author of the article, Dr. Reza Javaherdashti will be the trainer. Find out more about the training, read the interview with the trainer or short MIC Presentation on http://oilgas.flemingeurope.com/microbial-corrosion-train...