Using chemical and isotopic data to quantify ionic trapping of injected carbon dioxide in oil field brines

Journal Article · Wed Nov 01 00:00:00 EST 2006 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es060551a· OSTI ID:20838174

Raistrick, Mark; Mayer, Bernhard; Shevalier, Maurice; Perez, Renee J; Hutcheon, Ian; Perkins, Ernie; Gunter, Bill ^[1]

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1. University of Calgary, Calgary, AB (Canada). Applied Geochemistry Group, Department of Geology and Geophysics

Injection of carbon dioxide into depleted oil fields or deep saline aquifers represents one of the most promising means of long-term storage of this greenhouse gas. While the ultimate goal of CO{sub 2} injection in the subsurface is mineral storage of CO{sub 2} as carbonates, short-term ({lt}50 year) storage of injected CO{sub 2} is most likely to be accomplished by ionic trapping of CO{sub 2} as bicarbonate ions (HCO{sub 3}{sup -}) and hydrogeological trapping of molecular CO{sub 2}. Here, a technique is demonstrated for quantifying ionic trapping of injected CO{sub 2} as HCO{sub 3}{sup -} using geochemical data collected prior to and during 40 months of CO{sub 2} injection into a hydrocarbon reservoir at the International Energy Agency (IEA) Weyburn CO{sub 2} Monitoring and Storage Project, Saskatchewan, Canada. As a result of injection of CO{sub 2} with a low carbon isotope ratio ({delta}{sup 13}C value), fluid and gas samples from four selected production wells showed an increase in HCO{sub 3}{sup -} concentration and a decrease in {delta}{sup 13}C values of HCO{sub 3}{sup -} and CO{sub 2} over the observation period. Isotope and mass balance calculations indicate that, after 40 months of injection, {approximately} 80% of the HCO{sub 3}{sup -} in the reservoir brines sampled from the four wells formed via dissolution and dissociation of injected CO{sub 2}. This chemical and isotopic technique should be applicable to CO{sub 2} injection and storage in oil fields and in deep saline aquifers, provided there is sufficient carbon isotopic distinction between injected CO{sub 2} and baseline aquifer HCO{sub 3}{sup -} and CO{sub 2}. 37 refs., 3 figs., 1 tab.

• OSTI ID: 20838174
• Journal Information: Environmental Science and Technology, Vol. 40, Issue 21; Other Information: [e-mail]; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CARBON DIOXIDE INJECTION
BRINES
AQUIFERS
ACID CARBONATES
UNDERGROUND STORAGE
OIL FIELDS
ABANDONED SITES
SASKATCHEWAN
CANADA
CARBON 13