Kentucky

Gas-charged porosity can drive natural hydraulic fractures during exhumation. In the foreland fringe of the Appalachian Basin, exhumation allowed the propagation of east-northeast-striking neotectonic joints. These joints appear at shallow depths where they facilitate leakage to form an underpressured gas column.

A new phase of development in the Berea Sandstone, northeastern Kentucky, began in 2011. Because of low thermal maturities, oil production was surprising. The current study has shown that the area mature for oil is larger than expected, and that migration has occurred in the updip portions of the play.

Organic-rich shale from the Berea Sandstone in Kentucky and Ohio are high in sulfur and dominated by liptinite macerals. Because oil migrated from more to less thermally mature areas, the occurrence of petroleum liquids cannot be predicted directly from conventional thermal maturity proxies.

Oils from the Upper Devonian Berea Sandstone, northeastern Kentucky, are from a single family and a similar source rock. The most likely source rocks are the Devonian to Mississippian black shales with significant lateral migration. Nearby immature source rocks do not contribute to the hydrocarbons.

Organic matter in the Ohio and Marcellus Shales in the central Appalachian Basin was primarily derived from marine algae. This paper demonstrates local to short-distance (<50 mi) lateral migration for emplacement of Devonian-sourced oils into Devonian reservoirs of eastern Ohio.

Molecular and isotopic composition of natural gas from the Berea Sandstone and Ohio Shale are used to infer the source of gas and thermal maturity conditions under which it was generated. Migration along with basin uplift after the Alleghany orogeny may have contributed to a gas phase that exsolved from oil.

Berea reservoirs in eastern Kentucky are generally low-permeability, heterogenous, tight siltstones formed on a prograding marine shelf with traps less than 10 ft thick. Shallow production depths make this play economically advantageous to small and medium-sized companies.