Geologically Constrained Seismic Characterization and 3-D Reservoir Modeling of Mississippian Reservoirs, north-central Anadarko Shelf, Oklahoma
The onset of horizontal development in the current ‘Miss Lime’ play has significantly increased its viability as a major unconventional play. However, geologic controls on reservoir distribution and productivity are elusive. Preliminary data from northern Oklahoma show the Mississippian interval is stratigraphically and structurally complex and lithologies vary significantly from relatively high-porosity tripolite to low porosity chert and unaltered, dense limestone. The Mississippian carbonates of Oklahoma lie conformably above the Kinderhook and are unconformably truncated by the pre-Pennsylvanian unconformity. The Mississippian interval consists of four higher-order shallowing-upward cycles. Each cycle can be capped by an unconformable surface related to relative falls in sea level and regional tectonics which in turn has led to subaerial exposure and extensive diagenesis. The porous tripolitic chert most likely formed during periods of exposure and cycle development and although most common at the top of the Mississippian interval, may be found capping any of these cycles. In zones that exhibit dense unaltered limestone, fractures can be important controls on reservoir production. Mississippian lithologies described in core are calibrated to wireline logs from the same well and tied to seismic attributes. 3-D lithology and petrophysical models constrained by well and seismic attributes are generated. The models are used to infer depositional and diagenetic trends.
AAPG Datapages/Search and Discovery Article #90221 © 2015 Mid-Continent Section, Tulsa, Oklahoma, October 4-6, 2015