Stratigraphic Correlation Surfaces and 3-D Reservoir Model Construction: Constraints from Walther’s Law Models and Outcrop Analog Data

Abstract

A critical step in 3-D reservoir model construction is interpretation of stratigraphic-framework surfaces that guide data distribution between wells. Application of outcrop-scaled Walther’s Law depositional models that include information on depositional dip and facies-tract width is a basic guide for subsurface correlations. Ramp- crest grainstone complexes from the Permian of the Guadalupe Mountains, southeast New Mexico, and the Cretaceous of the Comanche Shelf, South Texas, form the bases for models with constrained depositional dips and facies-tract widths. Facies partitioning between transgressive and highstand systems tracts (TST and HST) as shown in outcrops of the Comanche Shelf Cretaceous along the Pecos River indicates that Walther’s Law models must be calibrated to the systems tracts level to gain maximum prediction of facies distribution and stratal geometry. Lacking these calibrated Walther’s Law models, correlations tend to produce an overly homogeneous lithostratigraphic correlation scheme, such as that applied to the Permian Seminole San Andres Unit of the Permian Basin.