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Multidisciplinary Characterization of Geomechanical Properties and Flow Behavior of the Coupled Arbuckle-Basement System, Payne County, Northern Oklahoma

Abstract

Resource plays such as the Mississippian Limestone of Oklahoma and Kansas are characterized by 95% hypersaline water production. Althought Oklahoma is currently covered by n-thousand water disposal wells, it is only the north-central part of Oklahoma that experiences a recent increase in seismicity. Clearly, geology has some impact on these events. Water disposal type II wells have been extensively correlated with induced seismicity in places like California, Texas, and the Arbuckle-basement system of Oklahoma. The Underground Injection Control program recognizes three necessary components for significant injection-induced seismicity: sufficient pressure buildup from disposal activities, faults, and a pathway allowing the increased pressure to communicate with the faults. We integrate 3-D seismic, well, and production data from Payne County, Oklahoma, to establish a stratigraphic and structural framework for Arbuckle-basement system as well as the overlying sedimentary section to the ground surface. We use seismic data conditioning and seismic attributes to better map structure, stratigraphy, and large scale diagenetic alteration of the Arbuckle, such as collapse features. Using this framework and data, geostatistical methods provide 3-D petrophysical models of shear velocity, compressional velocity, bulk density, and porosity input to geomechanical analysis of stress field and flow behavior. Well pressure and water-injection data provide estimates of ambient reservoir pressure showing some wells have been plugged, reducing injectivity. Further analysis will provide information that will potentially allow us to understand the reasons behind the triggering of seismic events in only certain areas of Oklahoma.