Inci Demirkanli, PhDPacific Northwest National Lab.P.O. Box 999, MS-IN: K9-33Richland, WA 99352(509) [email protected]
WaterAlternatingGasCyclingtoOptimizeCO2 MineralizationforGeologicalCarbonStorage:CascadiaProjectI. Demirkanli1, S. White1, M. White1, A. Bonneville1,and D. Goldberg2
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1 PacificNorthwestNationalLaboratory2 Lamont-DohertyEarthObservatoryofColumbiaUniversity
INTRODUCTIONSub-ocean basalt rock formations provide enormous storagecapacity for secure and safe storage of CO2 in mineralized form.Two recently completed field injection projects, CarbFix inIceland, and Wallula in Washington State, have both shown arapid mineralization of CO2 into stable carbonate in basaltformations. CarbFix injected fully dissolved CO2 in fresh water(25:1 water ratio by volume) and documented >95% carbonmineralization in basalt within 2 years. Similarly, Wallulainjected pure liquid CO2 into basalt and documented carbonmineralization within 2 years.As tested in the CarbFix project, various injection strategiesinvolving co- or alternating-injection of CO2 and water intobasalt reservoirs may improve the mineralization ofthermodynamically stable carbon solid phases. In addition,these strategies may help maximize injection volumes,minimize energy needs for pumping, and improve operationalefficiencies.
CASCADIAPROJECTLOCATION
Deep-seabasaltregionforCO2 sequestrationWaterdepths≥2700mSedimentthickness≥200mArea≅ 78,000km2
Targeted injection formation for the project is the sub-oceanbasalt basement in the Juan de Fuca ridge, a few hundredkilometers west of Vancouver Island, Oregon, and Washington:• Highly fractured, channelized, and porous (10-15%)• Sealed by impermeable fine-grained turbidities and
hemipelagic clay sediments.• Comprises both pillow lavas and massive flows containing
plagioclase, olivine, and clinopyroxene.
Goldbergetal.(2008)
BASALTPROPERTIES
WAGCYCLINGSIMULATIONS
BasaltMineral AssemblagesusedintheModelLayersBreccia(1000mDarcy,0.15porosity)• Plagioclase• Pyroxene• Mesostasis• Olivine
0.4054vf0.2180vf0.1971vf0.0295vf
2.68gm/cm33.21gm/cm32.31gm/cm33.32gm/cm3
Vesicular(100mDarcy,0.075porosity)• Plagioclase• Pyroxene• Mesostasis• Olivine
0.4412vf0.2372vf0.2145vf0.0321vf
2.68gm/cm33.21gm/cm32.31gm/cm33.32gm/cm3
Massive(0.001mDarcy,0.05porosity)• Plagioclase• Pyroxene• Mesostasis• Olivine
0.4531vf0.2437vf0.2203vf0.0329vf
2.68gm/cm33.21gm/cm32.31gm/cm33.32gm/cm3
ReactionNetwork
35AqueousSpecies11SolidSpecies
• STOMP-CO2 w/ECKEChem
NoWAG WAG
PRELIMINARYCONCLUSIONS• WAG cycling may improve mineralization by increasing the amount of CO2 in the
dissolved phase and also allowing larger surface area contact with the formation matrix.
• Optimization of WAG cycling using reservoir simulators is important for developing asite specific injection strategy.
• More accurate assessment for this project will depend on the updated reaction networkand kinetics as well as the site specific subsurface characterization data.
