(1) Indiana University Purdue University Fort Wayne, Fort Wayne, IN
Abstract: Self-organizing cellular models of carbonate deposition – evaluating controls on facies geometry
In the past, numerical simulation of shallow-water carbonate accumulation has focused upon relatively simple forward models incorporating a variety of allogenic and autogenic parameters. However, recent advances in modeling techniques have demonstrated the validity of cellular representations of carbonate systems. Spatial and stratigraphic distributions of simple binary (0, 1) facies patches produced by such simulations have been found to be similar to those observed in ancient and modern carbonate systems. However, such simulations have not been fully evaluated in terms of the importance of initial conditions and stochastic influences on resultant facies patterns. To this end, modeling efforts have been directed at assessment of continuous facies composition (all values between 0 and 1) models. This subtle, yet significant, alteration in the design of the cellular simulation allows for greater ease in observation of the sensitivity of model results to changes in initial conditions or the intensity of stochastic influences. Specifically, the roughness of facies patch edges is found to be controlled by relative strength of inter-cellular linking versus stochastic overprinting. Smooth edges are associated with relatively strong links and rough/irregular edges with increased stochastic influence. Likewise, the geometry of facies patches is found to be strongly controlled by the nature of the initial distribution of facies across the modeled depositional surface – the average composition and the statistical distribution of compositions are found to be of particular importance. As such, continuous composition cellular models of shallow water carbonate deposition provide important insights to the spatial and stratigraphic geometries of carbonate reservoirs.
AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana