Turbidity current modelling on geological time scales

A numerical model has been developed to simulate sedimentary architecture resulting from turbidity currents over geological time. The model is based on the cellular automata paradigm. The automata exchange matter and energy and are built in order to reproduce the physical processes which govern turbidity current behavior. The simulated architecture is the result of a given set of geological events. For each of these events a steady state is computed that is assumed to be representative of the average effect of a turbidity current on the construction of the sedimentary architecture. Using model capacities, we reproduce the first sequence of the Lower Pab channel complex formation and a unit of lateral stacked channels of the Angolan deep offshore Girassol field. The model results show that the simulated sedimentary facies distribution is realistic and this may allow a better prediction of the deposits organization in turbiditic systems. Moreover, this model improves stratigraphic modelling resolution and can take over diffusive methods at reservoir scale. The advantages of this numerical approach are a better identification and understanding of deposits heterogeneities and may provide a better representation of the spatial organization, geometry and variability of the geological units that form reservoir architecture in deep-sea clastic systems.