STAM, JEAN-MARIE T., IGG-TNO, Delft, Netherlands

ABSTRACT: Process-Based Modeling of the Aeloian Environment at the Dune Scale

Process-based models are quantitative models that simulate the physical process of sedimentation with the objective of reconstructing the spatial distribution, stratification, and properties of the subsurface. In this study, a two-dimensional, process-based model of the aeolian environment, at the dune-interdune scale, has been developed.

Sedimentation is governed by the variation of wind velocity over the topography, which is calculated analytically. Velocity calculations are coupled to a sediment transport equation, to determine where erosion and deposition occur. The resulting change in topography determines a new velocity field, which is then calculated. Features that the model simulates include ripple formation and dune migration, as well as the resulting internal sedimentary structures.

Process-based models can be used as tools to help interpret structures in ancient formations. This model has been applied specifically to reconstruct dune-interdune sequences observed in cores from the Rotliegendes, localized in the southern Permian basin (North Sea). The interdune strata are characterized by a low permeability, while the dune slipface strata have a much higher permeability. A flow simulation has been done on the aeolian section generated by the model, showing the effect of these heterogeneities on fluid flow.

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