Abstract: Exploration Considerations for Newman "Big Lime" Oil Reserves in Southeastern Kentucky
Jerry Tebo, T. Josh Stark, Charles Yough
The Newman "Big Lime" (Middle to Upper Mississippian) in the Appalachian basin portion of southeastern Kentucky contains tectonically influenced oil reserves. With the currently known primary production potential totaling a combined 30 million bbl of oil, these Big Lime traps are economically attractive targets. Drilling depths to test the Big Lime range from 2000 to 3500 ft, where sizable per well reserves (300,000 bbl of oil or more) are possible.
Fault remobilization within the Floyd County embayment has
influenced the pre-Big Lime erosional surface, resulting in paleovalleys and erosional scarps. Large Cambrian-aged growth faults define this structural embayment and are coincident with many of these shallower paleogeographic features. The Big Lime carbonates deposited in these features received preferential dolomitization during subsequent periods of fault remobilization (Permian?) as diagenetic fluids migrated through the resultant fractures. Hydrocarbons filled these reservoirs limiting water-charged porosity in the area. Both oil and dolomite are somewhat restricted to the southwestern margin of the embayment. Oil sourcing may be controlled by source rock variability and faulting. Dolomite distribution may be influenced by a large basement intrusive (?) that remobilized faults in the Leslie County Kentucky area.
Exploration methods employed in searching for Big Lime fields include remote geophysical surveys, seismic, core analysis, and diagenetic studies. This combination of tectonic, diagenetic, and stratigraphic controls on reservoir development can be used in exploration models for subtle carbonate traps throughout the craton.
AAPG Search and Discovery Article #90984©1994 AAPG Annual Convention, East Lansing, Michigan, September 18-20, 1994