Characterizing baseline soil gas conditions at the Containment and Monitoring Institute (CaMI) CO2 Injection Site in Alberta, Canada
Abstract
Carbon storage in deep geological reservoirs is a proven and effective method for reducing anthropogenic CO2 emissions to the atmosphere. However, refinements of monitoring methodologies are desirable to enable accurate tracking of injected CO2 in geological storage sites and to monitor for potential leakage of CO2 towards the near-surface environment. CMC Research Institutes Inc.'s Containment and Monitoring Institute (CaMI) operates a Field Research Site (FRS) near Brooks (Alberta, Canada) designed to test novel approaches for monitoring CO2 storage plumes and to detect any potential leakage. The facility is also used to gain a better understanding of methane fugitive emissions from hydrocarbon producing infrastructure. Prior to analyzing for potential fugitive CO2 or methane, the baseline vadose zone gas conditions and seasonal variabilities need to be characterized. Hence, baseline soil gas conditions were analyzed at CaMI prior to CO2 injection. Soil cores were extracted from six locations on site and grain size distributions were estimated revealing tight clay-rich soils derived from lacustrine and till sediments with a low hydraulic conductivity. Soil gas composition was sampled seasonally following the Alberta Energy Regulator's Directive 20 recommendation. Additionally, multilevel soil gas probes were installed at 0.5m, 1m, and 2m depths around CO2 injection and monitoring wells and at background locations. Gas compositions and δ13C values of CO2 were obtained via gas chromatography and mass spectroscopy respectively. Gas composition data revealed that CO2 is derived from respiration of soil organic matter and is also influenced by CO2 dissolution and oxidation of CH4. Isotopic analysis revealed soil gas CO2 with an average δ13CCO2 value of -22.4 ± 1.2‰. This is indicative of CO2 generated primarily through the respiration of C3 plant-derived organic matter and minor mixing with atmospheric CO2. The obtained information on baseline CO2 in the soil zone will be of critical importance for the monitoring of potential leakage of CO2 from the storage complex at CaMI once CO2 injection with a ẟ13C value circa -32.5‰ commences in 2018. This research was undertaken thanks in part to funding from the Canada First Research Excellence Fund.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.H23P2186R
- Keywords:
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- 0454 Isotopic composition and chemistry;
- BIOGEOSCIENCESDE: 1813 Eco-hydrology;
- HYDROLOGYDE: 1851 Plant ecology;
- HYDROLOGYDE: 1865 Soils;
- HYDROLOGY