Konzen, Graydon Leo2020-06-252020-06-252020-06-24vt_gsexam:26043http://hdl.handle.net/10919/99107Over the last decade, an increase in earthquake occurrence in Oklahoma and Kansas has been linked to oilfield wastewater injection disposal, particularly into the regionally underpressured Arbuckle Group. The Arbuckle is hydraulically connected to Precambrian basement through an extensive fracture system, which transmits pressure perturbations from wastewater injections to seismogenic depths. Previous studies have convincingly attributed induced seismicity to pore pressure diffusion and solid elastic stressing, both resulting from fluid waste injection. Recent work adds to the physical understanding of injection-induced seismicity by demonstrating that the density differential between injection fluids and formation brines may also drive fluid pressure into the seismogenic basement. In this thesis, variable density groundwater flow is modeled in a numerical simulation comprising parts of the Anadarko Basin, the Anadarko Shelf, the Cherokee Platform, and the Nemaha Fault Zone as well as injection data from 2006-2018. Results show buoyancy forces interacting with regional stratigraphic dip to force density-driven pressure transients into the deep Anadarko Basin, aligning with previously unexplained earthquakes in that region.ETDIn CopyrightHydrogeologyNumerical Groundwater ModelingInduced SeismicityGeographic Information SystemsThesis