Facies related geological model; a reliable method to describe complex reservoirs

The proposed methodology utilizes the concept of facies as the basis for reservoir characterization. Facies represent the elementary units of the reservoir. They are objectively determined through a log-based cluster analysis, and are fully characterized with petrophysical properties from cores. A stochastic model is used to distribute facies and related petrophysical parameters (porosity, permeability and irreducible water saturation) within the reservoir volume. Several equally probable reservoir realizations are generated from the same model and tested in a flow simulator. The realization providing the best history match is selected for production forecasts.