Glutaraldehyde Enhancement by D-limonene for Mitigating Biocorrosion of Carbon Steel by An Oilfield Biofilm Consortium

Abstract Microbiologically influenced corrosion (MIC) is one of the corrosion threats in the oil and gas industry. It is caused by environmental biofilms. Glutaraldehyde is a popular green biocide for mitigating biofilms and MIC. This work investigated the enhancement of glutaraldehyde efficacy by food-grade green chemical D-limonene in the biofilm prevention and MIC mitigation using an oilfield biofilm consortium. After 7–d incubation at 37oC with enriched artificial seawater (EASW) in 125 mL anaerobic vials, the 100 ppm glutaraldehyde + 200 ppm D-limonene combination treatment reduced the sessile cell counts on C1018 carbon steel coupons by 2.1 − log, 1.7 − log, and 2.3 − log for SRB (sulfate reducing bacteria), APB (acid producing bacteria), and GHB (general heterotrophic bacteria), respectively in comparison with the untreated control. The treatment achieved 68% weight loss reduction and 78% pit depth reduction. The 100 ppm glutaraldehyde + 200 ppm D-limonene combination treatment was found more effective in biofilm prevention and MIC mitigation than glutaraldehyde and D-limonene used individually. Electrochemical tests corroborated weight loss and pit depth data trends.