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dc.contributor.advisorWerth, Charles J.
dc.creatorFuchs, Samantha J.
dc.date.accessioned2017-09-14T13:48:27Z
dc.date.available2017-09-14T13:48:27Z
dc.date.created2017-05
dc.date.submittedMay 2017
dc.identifierdoi:10.15781/T2M03ZD17
dc.identifier.urihttp://hdl.handle.net/2152/61578
dc.description.abstractGeologic carbon sequestration is an emerging approach for mitigating climate change due primarily to point-source CO₂ emissions. Sequestration of carbon dioxide in deep saline aquifers prevents the release of CO₂ to the atmosphere. The Mt. Simon formation in the Illinois Basin is the site of a pilot-scale geologic carbon sequestration effort. It is a siliciclasic formation consisting of primarily quartz and potassium feldspar, cemented by illite-smectite and iron-illite clays. During CO₂ injection, carbon dioxide dissolves into pore water, resulting in a low-pH brine that can dissolve clays, carbonates, and other reactive minerals. In this work, the geochemical reactions resulting from the interaction of acidified-brine and reservoir rock are probed during and after aging samples of Mt. Simon sandstone in CO₂-saturated brine under reservoir conditions. During aging, contact angle measurements of supercritical CO₂ suggest the loss of iron-illite and increase of surface roughness. Post-aging, scanning electron microscopy coupled with electron dispersive spectroscopy revealed the loss of clays, greater exposure of quartz and K-feldspar grains, and apparent roughening, confirmed by XRD analysis and laser profilometer surface images respectively. Scratch tests were performed on both unaltered and aged samples, and the latter show a 63% decrease in fracture toughness. I conclude that acidified brine causes dissolution of clays and K-feldspar during carbon sequestration that weakens the Mt. Simon sandstone matrix along quartz and feldspar grain boundaries. This process may contribute to microseismic activity observed at the Mt. Simon sequestration site during and after CO₂ injection.
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.subjectGeochemistry
dc.subjectGeomechanics
dc.subjectCarbon sequestration and storage
dc.subjectClimate change
dc.titleGeochemical and geomechanical alteration of Mt. Simon sandstone due to prolonged contact with CO₂-saturated brine during carbon sequestration
dc.typeThesis
dc.date.updated2017-09-14T13:48:28Z
dc.description.departmentCivil, Architectural, and Environmental Engineering
thesis.degree.departmentCivil, Architectural, and Environmental Engineering
thesis.degree.disciplineEnvironmental and Water Resources Engineering
thesis.degree.grantorThe University of Texas at Austin
thesis.degree.levelMasters
thesis.degree.nameMaster of Science in Engineering
dc.creator.orcid0000-0002-5872-8120
dc.type.materialtext


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