A Robust Measure of Heterogeneity for Ranking Earth Models: The F-PHI Curve and Dynamic Lorenz Coefficient

Abstract

A new method for estimating heterogeneity in Earth models is presented. The new approach requires running a streamline simulator only a few timesteps, so multi-million cell models are evaluated in minutes. Using streamline time of flight and volumetric flow rate information from the simulation, a flow capacity diagram and sweep efficiency history can be determined. Five different measures of heterogeneity can be obtained from these two diagnostic plots. We then evaluated each of these measures of heterogeneity for 450 models that were constructed using a wide range of Dykstra-Parsons coefficient and correlation lengths, and 2 different well patterns. The measures of heterogeneity were plotted against discounted oil recovery to determine the best measure of heterogeneity. From this study we conclude the Lorenz coefficient – as determined from dynamic data – is the single best measure of heterogeneity.