Unsteady-State Relative Permeability Curves Derived From Saturation Data and Partial Derivatives Using Magnetic Resonance Imaging

Laboratory coreflooding experiments are performed to determine relative permeability curves which characterize flow behavior in petroleum reservoirs. Commonly, numerical simulations are used to solve the inverse problem and fit the coreflooding results, assuming functional shapes for relative permeability curves. In this work, the acquisition of rapid saturation profiles was used to derive relative permeability curves, without the need for pressure and volume reading, and assuming any functional forms for relative permeability curves. The magnetic resonance (MR) imaging method—spin echo single-point imaging (SE-SPI)—acquired precise saturation profiles that were used in evaluating saturation partial derivatives. In this paper, saturation profiles of displacement experiments and their partial derivatives were used to derive capillary dispersion, fractional mobility of phases, and model-free relative permeability curves for Bentheimer sandstones. In the drainage displacement experiment, the capillary dispersion dependency on saturation demonstrates a hyperdiffusion behavior in the leading edge of the front.