Microbiologically influenced corrosion (MIC) is a common problem in the oil and gas industry. MIC is an immense threat especially inside of pipelines, especially by Sulfate Reducing Bacteria (SRB). For this purpose, MIC by SRB was investigated in experiments using split-cell zero resistance ammetry (SC-ZRA) measurements. To understand the extent and activity of MIC by SRB, various experiments were conducted where carbon steel coupon was deployed in laboratory synthesized media, which was formulated from the oil and gas pipeline sludge using elemental analysis. SC-ZRA incubations were inoculated with SRB enrichment isolated from contaminated pipeline sludge. One side of the SC-ZRA is inoculated with SRB enrichment (WE1) and the other side of the SC-ZRA is kept sterile (WE2). Current and potential between the two coupons was measured. Series of batch experiments are also conducted with the same enrichment and synthetic media. When SC-ZRA was conducted for 30-days, biofilm attachment was not observed under scanning electron microscopy (SEM) as the biofilm was heavily encrusted by corrosion products. When the experiment was conducted for 17-days, some microbial attachment was observed but the organisms were covered with iron sulfide (corrosion product), which was formed as a byproduct due to microbial metabolism. Consequently, intense corrosion and pitting was observed on the coupon exposed to the SRBs in the 30-days run. Weight loss for WE2 was higher than WE1 at the end of the experiment. For the 17-days run, no pitting was observed for the inoculated coupons, and the WE1 side had a higher mass loss when compared to the WE2 side. SC-ZRA technique can be used to characterize microbial activity, in this work with SRB. This technique can also be used as a quick monitoring tool for detecting the extent of microbial corrosion for the oil and gas systems.


Microbiologically influenced corrosion (MIC) is one of the most aggressive forms of corrosion leading to infrastructure and equipment damage in various industries, including but not limited to the oil and gas industry,1 water systems,2 medical devices,3 marine environments,4 nuclear waste storage facilities,5 and aviation fuel systems6 and storage.7 MIC received great attention because of the increasing cost associated with corrosion damage, particularly in oil and gas industry. The overall cost of corrosion has been estimated to be approximately 3.4% in the global Gross National Product8 which equates to approximately $2.9 trillion in 2018.9 A conservative estimate shows that 20% of all corrosion in aqueous system is MIC,10 which accounts to billions of dollars in the US.

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