Field Demonstration of CO2 Leakage Detection in Potable Aquifers with a Pulselike CO2-Release Test

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• 作者：Changbing Yang ; Susan D. Hovorka ; Jesus Delgado-Alonso ; Patrick J. Mickler ; Ram贸n H. Trevi帽o ; Straun Phillips
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：December 2, 2014
• 年：2014
• 卷：48
• 期：23
• 页码：14031-14040
• 全文大小：525K
• ISSN：1520-5851

文摘

This study presents two field pulselike CO₂-release tests to demonstrate CO₂ leakage detection in a shallow aquifer by monitoring groundwater pH, alkalinity, and dissolved inorganic carbon (DIC) using the periodic groundwater sampling method and a fiber-optic CO₂ sensor for real-time in situ monitoring of dissolved CO₂ in groundwater. Measurements of groundwater pH, alkalinity, DIC, and dissolved CO₂ clearly deviated from their background values, showing responses to CO₂ leakage. Dissolved CO₂ observed in the tests was highly sensitive in comparison to groundwater pH, DIC, and alkalinity. Comparison of the pulselike CO₂-release tests to other field tests suggests that pulselike CO₂-release tests can provide reliable assessment of geochemical parameters indicative of CO₂ leakage. Measurements by the fiber-optic CO₂ sensor, showing obvious leakage signals, demonstrated the potential of real-time in situ monitoring of dissolved CO₂ for leakage detection at a geologic carbon sequestration (GCS) site. Results of a two-dimensional reactive transport model reproduced the geochemical measurements and confirmed that the decrease in groundwater pH and the increases in DIC and dissolved CO₂ observed in the pulselike CO₂-release tests were caused by dissolution of CO₂ whereas alkalinity was likely affected by carbonate dissolution.