Stable Isotope Approaches to Monitoring and Verification of Injected Carbon Dioxide at the Pembina Cardium Carbon Dioxide Monitoring Pilot, Alberta, Canada

Carbon capture and storage (CCS) is a promising suite of technologies that can assist in the mitigation of anthropogenic emissions of CO2 to the atmosphere from fossil fuel combustion. Monitoring of CCS operations is imperative in proving that CCS is safe and verifiable and thus can be deployed at a scale that is large enough to have an impact on global CO2 emissions.;Stable isotopes show CO2 migration within the reservoir. delta 13C values of produced CO2 show trends from baseline values towards that of injection CO2, revealing injected CO2 migration. Furthermore, it was demonstrated that equilibrium oxygen isotope exchange between injected CO2 and H2O is capable of changing the delta18O values of the reservoir water, and that the magnitude of the change revealed the pore-space saturations of CO 2 within the reservoir. Finally, an attempt was made to verify injected CO2 by integrating chemical, isotopic, production and geophysical monitoring data to determine a 'CO2 budget'. The dominant trapping mechanism was determined to be free phase CO2 trapping (physical trapping), accounting for more than 75% of the CO2, with solubility trapping in water and oil contributing the remaining ∼10 and ∼15% respectively. All CO2 injected into the reservoir was accounted for with an uncertainty level of +/- 15%.;Determination of pore-space saturation of CO2 has thus far been limited and the approach outlined in this thesis is both novel and extremely valuable in quantifying CO2 storage. Subsequently, this thesis provides one of the first attempts at complete quantification of CO2 and the relative role of trapping mechanisms at an operational CCS project.;The principal objectives of this thesis were to evaluate established monitoring methods and to develop new approaches to determine the fate of CO2 within the geological reservoir. The work was conducted at the Pembina Cardium CO2 Monitoring Pilot in Alberta, Canada. Baseline sampling took place in February 2005 before ∼70,000 tonnes of CO 2 were injected over three years with regular monitoring by geophysical and geochemical techniques during production.