Ohio Paleozoic Source-Reservoir Combinations: Source Rock Quality and Source-Oil Correlation Studies: ABSTRACT

Abstract

End_Page 1916------------------------------Although relatively simple structurally, the Interior Lowland area underlying Ohio and adjacent states constitutes a rich and varied hydrocarbon habitat. Structural style included influences of three subsidence episodes, broadly encompassing the Appalachian orogeny to the east and the Michigan and Illinois basins to the northwest and southwest, respectively. A sedimentary sequence covering the whole Paleozoic succession is variously present and becomes generally younger toward the southeast. Hydrocarbons are produced from numerous reservoir intervals within this Paleozoic section. Prominent among these are the Cambrian-Ordovician Knox Group, Ordovician Trenton Limestone, Silurian Medina Group, Devonian Oriskany and Vanango Sandstones, Mississippian Berea Sandstone, and Pennsylvanian c al measure sands. A variety of petroleum types, implying an equal variation in source rock characteristics, has been recognized. Reservoirs have been charged variously from finely textured organic-rich source beds cosedimented within the same succession. Whether the simplistic case of source charging of syndepositional or directly adjacent reservoir beds is normal or whether more complex long distance lateral and/or vertical emplacement processes are involved has yet to be subject to definitive study. Some of the more prominent source candidate rocks include the Conasauga Shale (Cambrian), Reedsville or Utica Shale (Ordovician), Ohio Shale (Devonian), and Bedford or Sunbury Shale (Mississippian), in addition to various Pennsylvanian intervals. Using kerogen pyrolysis-carbon isotopic source-oil correlation technology, it is possible to match petroleums with their precursor sources. End_of_Article - Last_Page 1917------------