Fossil Fuel Bioprocessing projects
Isotope Signatures of Reservoir Souring Processes
The primary goal of this project is to develop the use of isotopic measurements to monitoring reservoir processes associated with microbial reduction of sulfate (souring), including treatment. The approach is to develop a database of isotopic fractionation effects related to sulfate reduction that can be incorporated into reactive transport models to identify the types and extent of reactions that are occuring in the reservoir. Eventually the techniques developed can lead to application in operating oil wells.
Microbial sulfate reduction in oil reservoirs (souring) is a major problem facing the oil industry. To understand the causes and potential remedies for this process, we are exploring the use of isotope monitoring. Sulfate reduction is known to impart large isotopic shifts to the sulfate and sulfide that can be distinguished from other reservoir processes that may affect concentrations of these compounds. Key to the success of this method is using applicable isotopic fractionation factors for the processes being monitored. To address this, we are conducting a combination of controlled laboratory experiments, analysis of oil reservoir samples, and reservoir modeling.
Key activities this year include calibration of expected sulfur and oxygen isotope signatures during souring prevention and treatment in laboratory column experiments, development of experiments to identify other isotopic fractionating effects, developing applications of these techniques in operating oil reservoirs.
Published in 2014
Control of Sulfidogenesis Through Bio-oxidation of H2S Coupled to (Per)chlorate Reduction, P. A. Gregoire, A. Engelbrektson, C. G. Hubbard, Z. Metlagel, R. Csencsits, M. Auer, M. E. Conrad, J. Thieme, P. Northrup and J.D. Coates, Environmental Microbiology, doi: 10.1111/1758-2229.12156, April 4, 2014.
Inhibition of Microbial Sulfate Reduction in a Flow-Through Column System by (Per)chlorate Treatment, A. Engelbrektson, C. G. Hubbard, L.M. Tom, A. Boussina, Y. T. Jin, H. Wong, Y. M. Piceno, H. K. Carlson, M. E. Conrad, G. Andersen and J. D. Coates, Frontiers in Microbiology, doi: 10.3389/fmicb.2014.00315, 2014.
Temperature and Injection Water Source Influence Microbial Community Structure in Four Alaskan North Slope Hydrocarbon Reservoirs, Y. M. Piceno, F. C. Reid, L. M. Tom, M. E. Conrad, M. Bill, C. G. Hubbard, B. W. Fouke, C. J. Graff, J. Han, W. T. Stringfellow, J. S. Hanlon, P. Hu, T. C. Hazen and G. L. Andersen, Frontiers in Microbiology, doi:10.3389/fmicb.2014.00409, August 4, 2014.
Isotopic Insights into Microbial Sulfur Cycling in Oil Reservoirs, C. G. Hubbard, Y. Cheng, A. Engelbrekston, J. L. Druhan, L. Li, J. B. Ajo-Franklin, J. D. Coates and M.E. Conrad, Frontiers in Microbiology, doi: 10.3389/fmicb.2014.00480, 2014.
Published in 2013
Isotope Tracking of Microbial Sulfate Reduction in Oil Reservoirs, C. G. Hubbard, M. E. Conrad, A. Engelbrektson, P. Gregoire, J. Coates, Mineralogical Magazine, 77: 910