Subsurface sequence stratigraphy and reservoir characterization of the mississippian limestone (kinderhookian to meramecian), south central Kansas and north central Oklahoma

Both conventional and unconventional Mississippian reservoirs in the mid-continent are largely comprised of chert-rich carbonates of Osagean and Meramecan age. The conventional reservoir target is the Mississippian "chat," a high porosity, chert residuum interval found immediately beneath the Mississippian-Pennsylvanian unconformity. The unconventional reservoir target occurs in the lower porosity, cherty, mud-rich intervals that occur in the lower portion of the Mississippian succession. There has been considerable debate surrounding the sequence stratigraphic interpretations, depositional models, and formation names applied to the reservoir intervals within the subsurface. Another major issue with regard to the subsurface is the stratigraphic position and origin of tripolitic chert development. Previous outcrop studies within the Mississippian outcrop belt, mud logs, and well log correlations have been utilized to facilitate the application of sequence stratigraphy to the subsurface succession. Reservoir intervals appear to be preferentially developed beneath the Osagean-Meramecian and Mississippian-Pennsylvanian boundaries. The proposed depositional model challenges previous assignments of tripolitic chert development to what has been called the Reeds Spring Formation in the subsurface.