Semi‐Analytical Modeling of Rate‐Dependent Relative Permeability in Heterogeneous Formations

Abstract

AbstractRelative permeability (kr) is an important property characterizing multi‐phase flow in porous media, in particular considering applications of oil and gas production or CO2 storage in subsurface formations. Coreflooding experiments are the most common method of determining kr, usually conducted at a given total injection rate. However, kr is known to be a rate dependent effective property due to capillary heterogeneity effects and therefore full characterization requires conducting experiments at different flow rates, a complex and time consuming process. This work presents a new approach for calculating rate dependent effective kr curves based on a 1D semi‐analytical solution for steady state flow. The method entails calibrating a 1D permeability structure to represent the 3D flow of coreflooding experiments. Then, the calibrated 1D model is used to estimate kr curves at varying rates. We apply the method to three cases, two synthetic and one based on experimental data. Results show applicability for a wide range of flow rates.