Geological Mapping of Early Diagenetic Bodies as a Tool to Distribute Permeability in a Mature Giant Carbonate Field

Abstract

Abstract Revealing the coherency between geology and petrophysics in a mature carbonate field in order to provide 3D distribution of permeability is challenging. This paper shows how integration of early diagenetic processes is a prerequisite in understanding the behaviour of a heterogeneous carbonate field. However, mapping of early diagenetic overprint requires the preliminary mapping of the main depositional belts per stratigraphic sequence as the relevant diagenetic processes occurred during or shortly after deposition. For instance, diagenetic processes associated with vadose dissolution or reflux dolomitisation significantly enhance matrix permeability of the reservoir. Mapping of diagenesis has therefore been used as a tool to constrain permeability distribution within depositional sequences in combination with the interpretation of available dynamic reservoir data. The resulting geomodel better honours the heterogeneities and the dynamic behaviour of the field.