Abstract

Throughout the 1960s, Morrow County, Ohio was one of the biggest oil producing regions in the nation and continually produces today. However, following the boom of the 1960s, insufficient exploration within the region has resulted in an unclear explanation as to the reasoning for large amount of oil produced from this part of the western Appalachian Basin (Fig. 1). The Copper Ridge Dolomite is the primary producer in the area, and is sourced from an unknown unit that may be locally absent but extensive downdip (Dolly and Busch, 1972). Additionally, it is speculated that faulting within the basement rock and regional anticlinal doming exerts an important control on trapping, and may explain the high volume of oil produced from Morrow County (Blaxton, 1996).

Approximately 30 million barrels of oil and 5 million cubic feet of gas have been produced from Morrow County since 1959 (McClish and Roberts, 1989; DrillingInfo, 2020). Production in Morrow County is split into 16 different civil townships, with the eastern portion of the townships producing the least and the western producing the most (Fig. 2). Lincoln Township has the greatest production at 5 million barrels of oil, whereas the adjacent Westfield Township does not produce at all. The string of Canaan, Gilead, Cardington, Lincoln, and Peru townships indicates a possible north-south faulting system or some other trapping mechanisms with linear extent (Fig. 2). Mapping this system can explain the lack of production or the unexplored potential in Westfield Township. Eastern Morrow County is in direct line of hydrocarbon migration from downdip, but lacks the evidence of significant hydrocarbon accumulation, which could be the result of faulting in the area.

In order to gain insight into significant hydrocarbon production in Morrow County, we propose to better characterize and map the structural architecture of the basement in the region by analyzing an existing dense network of historic well log data from 2484 wells to create structure and isopach maps (Fig. 3). A key aspect to this study is to correlate stratigraphic horizons across the field within the Cambrian-Ordovician strata to determine locations of thinning and thickening that are translated throughout the strata, and disruptions to the structure indicating lineaments. Faults will be examined for possible hydrocarbon migration and structural trapping by mapping the location, spatial extent, and trend of the anticlinal doming as well as characterizing porosity, permeability, and lithology of the domes. Resulting data from the study allow the relation of these findings to potential exploration within Morrow County and/or creating an analog for future exploration within similar settings in the Appalachian Basin.