Impact of Nitrate-Mediated Microbial Control of Souring in Oil Reservoirs on the Extent of Corrosion

• Published in: Biotechnology progress Vol. 17; no. 5; pp. 852 - 859
• Main Authors: Nemati, Mehdi, Jenneman, Gary E., Voordouw, Gerrit
• Format: Journal Article
• Language: English
• Published: USA American Chemical Society 01.09.2001; American Institute of Chemical Engineers
• Subjects: Biodeterioration. Biofouling; Biological and medical sciences; Biotechnology; Corrosion; Desulfovibrio; Desulfovibrio - metabolism; Fundamental and applied biological sciences. Psychology; Gram-Negative Chemolithotrophic Bacteria - metabolism; Industrial applications and implications. Economical aspects; Microscopy, Electron, Scanning; Nitrates - metabolism; Nitrates - pharmacology; Oxidation-Reduction; Petroleum - microbiology; Sulfides - metabolism; Sulfides - pharmacology; Sulfur-Reducing Bacteria - metabolism; Thiomicrospira; Microbial activity; Sulfate-reducing bacteria; Acid corrosion; Oil field; Nitrates; Bacterial corrosion; Oil industry; Sulfides; Microbiological control; Desulfovibrio; Bacteria; Thiomicrospira; Microbial community
• ISSN: 8756-7938; 1520-6033
• DOI: 10.1021/bp010084v

The effect of microbial control of souring on the extent of corrosion was studied in a model system consisting of pure cultures of the nitrate‐reducing, sulfide‐oxidizing bacterium (NR‐SOB) Thiomicrospirasp. strain CVO and the sulfate‐reducing bacterium (SRB) Desulfovibriosp. strain Lac6, as well as in an SRB consortium enriched from produced water from a Canadian oil reservoir. The average corrosion rate induced by the SRB consortium (1.4 g m−2 day−1) was faster than that observed in the presence of strain Lac6 (0.2 g m−2 day−1). Examination of the metallic coupons at the end of the tests indicated a uniform corrosion in both cases. Addition of CVO and 10 mM nitrate to a fully grown culture of Lac6 or the SRB consortium led to complete removal of sulfide from the system and a significant increase in the population of CVO, as determined by reverse sample genome probing. In the case of the SRB consortium addition of just nitrate (10 mM) had a similar effect. When grown in the absence of nitrate, the consortium was dominated by Desulfovibrio sp. strains Lac15 and Lac29, while growth in the presence of nitrate led to dominance of Desulfovibrio sp. strain Lac3. The addition of CVO and nitrate to the Lac6 culture or nitrate to the SRB consortium accelerated the average corrosion rate to 1.5 and 2.9 g m−2 day−1, respectively. Localized corrosion and the occurrence of pitting were apparent in both cases. Although the sulfide concentration (0.5−7 mM) had little effect on corrosion rates, a clear increase of the corrosion rate with increasing nitrate concentration was observed in experiments conducted with consortia enriched from produced water.