Integrated Geologic Analysis of East Canton Consolidated Field for CO2-EOR
Ohio’s East Canton Consolidated Field has produced 95 million barrels (MMBbl) oil from the Medina group’s Clinton Sandstone since 1966, with another 10 MMBbl primary recovery remaining. Enhanced oil recovery (EOR) using carbon dioxide (CO2) creates economic benefit by extracting previously unrecoverable oil reserves while providing environmental benefit by storing carbon in the “Clinton” a mile underground. Reservoir modeling of CO2-EOR estimates an additional 76 to 279 MMbbl oil could be recovered. Engineering an effective recovery operation is dependent on understanding how this oil reservoir was formed geologically through time. Diagenesis of heterogeneous Silurian deltaic clastic facies accounts for a fair to poor correlation of geophysical log porosity to oil production. Thus, an integrated geologic analysis of East Canton Consolidated Oil Field was performed to assist engineers in designing a more effective CO2-EOR operation. This case study utilized published reports, public data and the Midwest Regional Carbon Sequestration Partnership’s (MRCSP) database to perform a comparative analysis of factors thought to influence production. A portion of the field studied by Riley and others in 2011 and a larger area studied by Mishra in 2015 were re-evaluated using comparative analysis. The highest oil yield is found to occur in alignment with two or more cross-structural fracture sets with thick sandstone distributary systems in a hundred-foot structural depth interval where a greater than average density of modern stress field fractures occur. This case study proposes that cross-structural fracture trends served as a conduit for fluid migration during episodic tectonic events when aligned with the paleo stress field, first filling pore spaces in permeable sandstones with oil expelled from underlying Point Pleasant organic source rock. Later-stage hydrothermal fluids forming diagenetic cements along the cross-structural fractures trapped the oil in place. The monoclinal structure dipping eastward into the Appalachian Basin segregated fluids into gas updip and water downdip of the oil reservoir, and the current stress field fractures enhance permeability. Laterally extensive vertical seals will likely constrain CO2 used to move oil, and include the overlying “Packer Shell” dolomites, interbedded Medina group shales and the underlying Queenston shale. These findings can be extrapolated to the entire 164,000-acre field while the comparative analysis methodology can be used to evaluate CO2 in other “Clinton” oil fields.
AAPG Datapages/Search and Discovery Article #90373 © 2019 AAPG Eastern Section Meeting, Energy from the Heartland, Columbus, Ohio, October 12-16, 2019