Application of Sequence Stratigraphic Analysis to Thin Cratonic Carbonate-Dominated Shelf Cycles (Upper Pennsylvanian) in Mid-Continent: ABSTRACT

Abstract

Seismic sequence analysis has proven extremely effective and practical in identifying potential petroleum reservoir plays. This analysis requires defining stratal units, 10s of meters in thickness, bounded by unconformities and translated on seismic traces. A similar approach, using different techniques, is applied to subsurface data to improve the resolution of the sedimentary architecture in thin Upper Pennsylvanian cratonic cycles. These cycles reflect the relative rise and fall of sea level, aspects of which vary between cycles in terms of rate, magnitude, and duration. Understanding aspects of the fall of relative sea level and accordant sediment aggradation and progradation is important in order to recognize the character of the basinward migration of favorable shallow-water carbonate facies tracts. Because of their short duration, individual aggradational and progradational events cannot be resolved via biostratigraphy. Correlatable events, bounded by omission surfaces, can be recognized through detailed lithofacies analysis of cores. Wireline logs provide a basis from which to extrapolate thicker (>0.7 m) core-derived lithofacies. Very high resolution CMP seismic profiling (less than or equal to300-Hz) has been used successfully at penetration depths to about 450 m to distinguish and characterize reflections from beds (1.5 m minimum) within cycles and internal depositional surfaces within thickermore » deposits. Potential exists for using detailed seismic sequence analysis to assist in defining geometry of these component beds at reservoir scale.« less