Lithostratigraphy and diagenesis of the Upper Pennsylvanian (Missourian) Lansing-Kansas City Groups in Rooks County, Kansas

Research project (M.S.)--Wichita State University, Fairmount College of Liberal Arts and Sciences, Dept. of GeologyThe Upper Pennsylvanian (uppermost Missourian) Lansing-Kansas City Groups (LKC) are prime oil reservoirs targeted by many petroleum companies exploring in Kansas and Nebraska. The LKC groups are a series of cyclothems with carbonate and terrigenous clastic components. A 240 foot, full-diameter core from within Dopita Field in Rooks County, Kansas that recovered the entire LKC section, along with thin sections and plugs (porosity and permeability tested), were studied to determine the depositional facies and diagenetic controls on reservoir development in these rocks, and to understand which producing zones in the study area, if any would be candidates for a waterflood. The LKC section in the core (zones labeled A-L from top to bottom) was divided into lowstand-transgressive-highstand complete cycles and incomplete sub-cycles. A complete cycle consists of, from base to top: (i) a section with evidence of subaerial exposure,(ii) a transgressive-systems tract and ensuing maximum flooding surface, (iii) a regressive highstand-systems tract, and (iv) another section suggestive of subaerial exposure. An incomplete sub-cycle is represented by the upward change from transgression to highstand without evidence of subaerial exposure. Throughout the core, there were 6 complete cycles and 10 incomplete sub-cycles identified. The study showed that any porosity and permeability (along with oil shows) present in the rocks had developed during times of subaerial exposure within shallow-water carbonate sands deposited in the highstand systems tracts of cycles. Currently, plans are being made to begin waterflooding the south end of the Dopita Field. The results from this study are being implemented in deciding which zones to flood