Reduced Emission In Situ Oil Sands Recovery Processes

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The recoverable volume of heavy oil and bitumen in W. Canada is ~170 billion barrels with value in the trillions of dollars. Serious challenges face recovery processes for these resources due to their in situ viscosities which are typically thousands to tens of thousands of centipoise for heavy oil and hundreds of thousands to millions of centipoise for oil sands (water has viscosity 1 centipoise). The energy and emissions intensities of oil sand recovery processes are high compared to conventional oil processes; thus, on a global stage, heavy oil and bitumen appear relatively unattractive as liquid fossil fuels given their high energy and emissions intensities. To maintain a social license to operate, the energetic and environmental efficiencies of oil sands extraction must be equal or lower than that of conventional oil. Results from the applicant's previous NSERC DG revealed that oil sands recovery processes are not only physical ones where oil viscosity decreases under steam-based heating but also chemically reactive ones that result from steam-oil and steam-rock reactions. The reactions that occur include aquathermolysis (hydrous pyrolysis), thermal cracking (pyrolysis), and steam-water-rock geochemical reactions. The key issue is that the produced gases not only include solution gas (mainly CH4) but also CO2 and H2S from the reactions and thus the total emission intensity includes both CO2 from steam generation and reaction-based CO2. Oxyfuel-fired direct contact steam generators produce steam within the burner flame producing a steam-CO2 mixture. Thus, if CO2 from steam generation is injected into the formation and a means was discovered to mineralize both injected and generated CO2 within the formation as the oil is produced, the recovery process would have zero CO2 emissions. The objective of the proposed research program is to determine a set of operating conditions and injection strategies for steam-based recovery processes where all of the generated CO2, whether from steam or in situ generation, and H2S (from in situ aquathermolysis) is sequestered as solid in the reservoir as the recovery process evolves. The research program consists of both theoretical and experimental projects to understand the kinetics of conversion of CO2 and H2S to solid form in a sand matrix and to use the results to find new operating conditions and injection strategies to maximize CO2 and H2S sequestration, oil rates and recovery factor. Over the 5-year research program, it will provide comprehensive training to 10 HQP (2 PhD, 3 MSc, and 5 BSc students).**