Incorporating Rock Types, Pore Systems and Capillary Forces in the Modeling of Water Saturation in Carbonate Reservoirs

Summary The three dimension stochastic modeling of initial water saturation (SW) and permeability (K) has been discussed since several decades among petrophysicists, geologists and geostaticiens. The studies showed that such modeling process becomes more challenging for carbonate reservoirs that hold more than sixty percent of the world’s oil and forty percent of the world’s gas reserves. In fact, the carbonate rocks hold multiple and complex pore systems due to the deposition environment, the diagenesis and deformation processes. This complexity impacts the capillary forces that govern the drainage and the imbibition processes in the carbonate reservoir. Several methods were proposed for the assessment of SW and K in the carbonate reservoirs by incorporating mercury injection capillary pressure data (MICP) in one dimension. We propose to improve those methods by proposing a workflow for three dimension modeling of SW and K, in carbonate reservoirs, through the integration of the MICP data, the rock types, and the heterogeneity of the pore systems. The paper will present in details the different steps of the workflow, and the results of the application of this workflow to a carbonate gas reservoir.