Date of Award
Master of Science (MS)
Dr. Hendratta Ali
Siliceous – carbonate intervals in the Mid-‐Continent are proven producible hydrocarbon reservoirs, however they have been understudied compared to more classic type reservoirs because of difficulties in characterization and correlations due to the heterogeneity and complex nature of their lithofacies. Understanding the characteristics of siliceous – carbonate lithofacies through macro and micro scale analysis can enhance the assessment of reservoir attributes and quality. Core, thin sections, and well logs were used to determine characteristics of a Mississippian (Osagean – Meramecian) interval (2,906 ft. and 2,946 ft.) from Canton SWD 1-36 located in McPherson County, Kansas, USA. Qualitative and quantitative analyses were used to identify and characterize lithofacies for interpretations of stratigraphic placement, depositional environments, cyclicity, and diagenetic history. The purpose of this research was to characterize from a Mississippian age core located in a relatively understudied region in Kansas, to describe petrophysical properties for reservoir quality. Three lithofacies are identified for the study interval: dolomitic mudstone with chert nodules (DM), fossiliferous wacke – pack – grainstone (FWPG), and tripolitic chert conglomerate (TCC). Lithofacies are placed stratigraphically within the Warsaw and Burlington-Keokuk formations. The depositional environment of the study interval is interpreted to be shallow, warm water, inner to middle carbonate ramp system. Four dirtying-upward trends are recognized in the interval, which suggest high-frequency 4thor 5th order depositional cycles. Diagenetically, the interval was subject to a complex history with most diagenetic events occurring relatively soon after deposition in a mixing zone of meteoric phreatic and marine vadose zone environments. Six stages of diagenetic events are recognized. Early diagenetic events (leaching, recrystallization, dolomitization, and first generation fracturing) indicate marine, meteoric, and shallow burial conditions. Later diagenetic changes occurred through intermediate and deep burial events represented by the further dissolution, authigenic quartz (silica) replacement of calcite, styolitization, and grain compaction. Petrophysical results show that high porosity occurs in TCC lithofacies and high permeability occurs in TCC lithofacies. Thus this facies is best suited as a reservoir rock for hydrocarbon, saltwater injection, or CO2 sequestration.
Copyright 2016 John Hunter Green
Green, John Hunter, "Petrophysical Attributes, Depositional Environment, And Diagenetic History Of A Mississippian Interval From McPherson County, Kansas, USA" (2016). Master's Theses. 33.