Trenton Limestone--Glamorous Old Play or Attractive New Frontier?
KEITH, BRIAN D., Indiana Geological Survey, Bloomington, IN
The Lima-Indiana trend of northwestern Ohio and north-central Indiana, discovered in 1884, was America's first giant petroleum play. Nearly 500 million bbl of oil and an estimated 2 tcf of natural gas were produced from the trend. As a result, a mystique became attached to the Trenton Limestone (Ordovician) that persisted until the next significant discovery, the Albion-Scipio trend discovered in southern Michigan in 1956. To date, approximately 130 million bbl of oil have been produced from the Albion-Scipio trend. The mystique only increased even though other Albion-Scipio-like fields were not found until 1983 when the Stoney Point field was discovered a few miles away from Albion-Scipio.
Trenton reservoirs are difficult to find, and once found, they possess highly variable, but generally low, porosity and permeability. In a few areas, such as along the Bowling Green fault zone in Ohio and the Albion-Scipio trend, wells with very high productivities (9000 to 12,000 bbl of oil/acre) and high initial flow rates (hundreds to thousands of bbl/day) are found. These wells fuel the mystique.
Mystique aside, the Trenton has potential as a new frontier in two ways. Large areas of the Appalachian, Illinois, and Michigan basins contain Trenton rocks at depths of 5000 to more than 10,000 ft, and are virtually undrilled. In addition, the application of new technology, such as high-resolution seismic and horizontal drilling, has a vital role to play. Past history indicates that the mystique will endure for a long time even without new discoveries and may drive exploration into new frontiers.
AAPG Search and Discovery Article #91005 © 1991 Eastern Section Meeting, Pittsburgh, Pennsylvania, September 8-10, 1991 (2009)