AITKEN, JOHN F., and STEPHAN S. FLINT, University of Liverpool, Liverpool, England

ABSTRACT: Reservoir Anatomy within a Sequence Stratigraphic Framework: The Pennsylvanian Breathitt Group of Eastern Kentucky

Detailed quantitative sequence stratigraphic analysis and three-dimensional (3-D) modeling of the fluvio-deltaic Pikeville, Hyden, and Four Corners formations of the Breathitt Group, eastern Kentucky, indicate that it is possible to make confident deterministic correlations of sand bodies at offshore development well spacings. The key to high-confidence correlation is the delineation of the 3-D architecture of third-order composite sequences, which are seismically mappable, and the recognition of internal fourth-order sequences, which are stacked into lowstand, transgressive, and highstand sequence sets.

Volumetric partitioning of reservoir sand bodies between systems tracts and sequences allows prediction of channel sandstone geometries and channel: crevasse splay ratios. Furthermore, channel-fill type is predictable from the sequence stratigraphy. Within 13 studied fourth-order sequences, incised valley fills represent the main reservoirs, which are laterally continuous over tens of kilometers. Sand bodies within transgressive and early highstand systems tracts are usually filled by siltstones or heteroliths and have geometries less than 1.0 km in width. Within fourth-order sequence sets, incised valley fills are sometimes vertically stacked to produce anomalously thick fluvial sand bodies. These are the prime potential producing zones within coastal plain reservoirs.

High-resolution sequence stratigraphy thus provides a deterministic approach to correlation and 3-D modeling. Use of the Stratamodel geocellular modeling system permits circulation of connectivities for different systems tracts and sequence sets, thus allowing the development of conceptual models for perforation policy in complex "jigsaw-type" reservoirs.

AAPG Search and Discovery Article #90990©1993 AAPG International Conference and Exhibition, The Hague, Netherlands, October 17-20, 1993.