ABSTRACT: Trenton and Black River Reservoirs-Still a Structural Play

Brian D. Keith, Indiana Geological Survey, Indiana University, Bloomington, IN

The time span from the discovery of the Lima-Indiana trend in northwestern Ohio in 1884 to the present deep gas play in the Appalachian Basin in New York and West Virginia represents more than 100 years of successful petroleum exploration for Trenton and Black River carbonate reservoirs. Various studies have suggested that the structural patterns of Paleozoic rocks in the interior of the eastern North America craton are tied to basement structures associated with Precambrian and Cambrian deformation and rifting. Far field stresses from Paleozoic collisional events reactivated many of the older faults causing faulting, folding, and fracturing of the Paleozoic rocks including the Ordovician Trenton and Black River carbonates.

Reservoirs in the Trenton and Black River fall into four general categories: (1) grainstone bodies on anticlinal structures in southern Illinois and central Kentucky; (2) up-dip pinch out of regionally dolomitized limestone in north central Indiana and northwestern Ohio; (3) fractured limestone with unclear or unknown associated dolomitization in eastern Illinois, central Kentucky and Tennessee, areas of New York, and West Virginia; and (4) fractured limestone with associated hydrothermal dolomitization in southern Michigan, northwestern Ohio, southern Ontario, and the southern tier of New York. The most prolific hydrocarbon reservoirs are found in this last category.

These reservoirs will continue to be difficult to find, but the use of new structural play concepts, such as those responsible for recent successes in untested areas of New York and West Virginia will ensure the continuation of the long exploration history of these enigmatic carbonates.

Search and Discovery Article #90907©2000 AAPG Eastern Section Meeting, London, Ontario, Canada