Seismic-Stratigraphic Resolution of Depositional Systems and Reservoir Facies Occurrence, Permian Basin

S. J. Mazzullo, A. M. Reid

The seismic-stratigraphic techniques of Peter Vail and others in 1977 are useful in reconstructing gross depositional patterns in sedimentary basins, particularly for inferences regarding relations among large-scale depositional sequences. However, reservoir facies in the Permian basin most commonly occur as components of individual sediment packages within small-scale depositional sequences (1-10 m.y. duration), which are less amenable to seismic resolution without additional detailed geologic information. Integrated regional lithologic, fusulinid biostratigraphic, and seismic analyses of subsurface sections allow the identification of major depositional sequences, component sediment packages ("parasequences"), and evolutionary changes in depositional systems at a tempor l scale finer than that usually discernible by seismic interpretations alone. Extrapolation of such data can be used to construct detailed basin subsidence, sea level fluctuation, and sedimentation rate curves through time for the section under consideration. These curves can then be used to correlate seismic-defined depositional sequences and parasequences over large areas of a basin. Time-slice facies maps for specific units within a stratigraphic succession, including the predicted areal distributions of potential reservoir facies, can be prepared from series of wireline log and corresponding seismic sections. Individual time-bounded depositional sequences of short duration (0.33-2.36 m.y.) can be superimposed directly onto conventional or inverted seismic lines in areas of limited we l control.

AAPG Search and Discovery Article #91034©1988 AAPG Southwest Section, El Paso, Texas, 21-23 February 1988.