Subsurface Facies Analysis of the Rose Run Sandstone Formation in south eastern Ohio
The Upper Cambrian to Ordovician Rose Run Sandstone and its equivalents (Upper Sandstone Member of the Knox Formation) were deposited in the Appalachian Basin in Ohio, Kentucky, West Virginia, and Pennsylvania. The Rose Run Sandstone, which is entirely subsurface in Ohio, is a complex hydrocarbon play because of periodic changes in sea level, the Knox unconformity, and structural complexities (Riley et al., 1993). Therefore, interpreting the depositional environment would aid in exploration for hydrocarbons within the formation.
The purpose of this study is 1) to use subsurface facies analysis to help interpret the depositional environment of the Rose Run Sandstone and create a facies model, 2) to apply the facies model to gain further insight on how these depositional environments contributed to the complexity of this active petroleum exploration play, and 3) to evaluate the facies model so as to improve interpretations from wells where only geophysical data are available.
This research involved detailed analysis of diamond drill core and interpretation of geophysical logs (gamma-ray, density, and neutron-porosity logs) from four wells in SE Ohio. The wells included: 1) Stone Resources and Engineering Company well number 2989 from Coshocton County, 2) Columbia Gas Transmission Corporation well number 2923 from Morgan County, 3) NU Energy Corporation well number 2898 from Jackson County, and 4) Aristech Chemical Company well number 3409 from Scioto County.
Based on the analysis of the four cores, sedimentary structures such ooids and intraclasts, mottling, algal lamination, flaser bedding, wavy bedding, lenticular bedding, heterolithic sandstone and mudstone, current ripple lamination and low-to medium-angle tabular cross bedding, tidal rhythmites, double mud drapes and herringbone cross stratification were used to interpret the paleoenvironment of the Rose Run Sandstone as a tidally-influenced, subtidal environments with associated tidal flat deposits and related subtidal channels with migrating sandbars. Other workers have varying interpretations of the Rose Run Sandstone depending in part on the previous definition of the upper and lower contacts for the unit, and the location of their wells.
These subsurface facies were correlated to their given gamma- ray, density, and neutron-porosity log signature slice by attributing a lithofacies from the core to a given geophysical log slice through a process called supervised classification. Well 3409, which served as the control well, was used in assigning core attributes to the geophysical logs, while well 2923 was used as the experimental well, for carrying out the sequence stratigraphic model using geophysical logs alone based on the control well. Excellent correlation of core data with gamma- ray, density, and neutron porosity log coverage enabled a facies interpretation and correlation from well 3409 to well 2923.
School:Bowling Green State University
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:rose run sandstone depositional environment sedimentary structures facies geophysical log
Date of Publication:01/01/2008