Eastern Section Meeting

Datapages, Inc.Print this page

Oil Production From Low-Maturity Organic-Rich Shale: An Example from the Devonian New Albany Shale in the Illinois Basin, Breckinridge County, Kentucky


The Devonian New Albany Shale is recognized as the primary source rock for Illinois Basin oil and gas production. As a shale reservoir, the New Albany is historically a gas producer. In 2011, Endeavor Energy Resources LP drilled and completed four natural gas producers in the Grassy Creek Member at the top of the shale in Breckinridge County, Kentucky. In 2012, Endeavor filed new completion reports indicating these wells had transitioned to combined oil and natural gas producers. In 2013, Hard Rock Drilling completed two oil producers to the northwest of the Endeavor wells. In approximately 18 months, these six wells have produced 23,649 barrels of oil and 246 MMcf of gas.

Oil, gas, and well cutting samples were acquired from two Endeavor wells and the Kentucky Geological Survey No. 1 Blan well. Rock-Eval, isotopic, and chromatographic analysis indicates the New Albany is a good, early mature source rock with Type I and Type II oil-prone marine kerogen that was thermogenically altered to natural gas and oil. Low reservoir pressures and geochemical fingerprinting suggest that the hydrocarbons were generated in place or very locally with minimal migration. The low Tmax and high hydrogen index (from Rock-Eval), presence of wet gas, and a large fraction of light gasolines in the produced oils are not consistent with classic measures of thermal maturity, however. Additional study is needed to develop a better understanding of this production and realistically assess the oil and gas potential of the New Albany Shale.