A Consistent Workflow to Re-evaluate the Hydrocarbon Distribution in a Giant Carbonate Reservoir in the Middle East

Abstract

Summary We apply a new and geologically consistent workflow to re-evaluate the saturation distribution in a giant and complex carbonate reservoir from the Middle East that comprises a thick transition zone. The workflow makes use of all the available capillary pressure, porosity, and permeability, data, irreducible water saturations, Archie exponents and cementation exponents. By using these data, the new workflow enables us to model hydrocarbon distributions more robustly. Hence the resulting 3D saturation model honours saturation logs at the wells exactly and allowed us to identify new reservoir compartments, leading to improved estimates of hydrocarbon reserves, and an estimated change in reserves of over 20%. The workflow is embedded in the Geo2Flow software and can be run conveniently from Petrel. The new saturation distribution needs to be considered as a new model scenario for any subsequent dynamic reservoir simulations.