Magnetic resonance imaging of immiscible-fluid displacement in porous media

Magnetic resonance imaging is used to study oil and water invasion in a model porous medium. Im­ages taken normal to the How direction are processed to give both the oil saturation and the fractal char­acter of the oil distribution . These images reveal qualitative differences between the cases of invasion by the wetting (water) and nonwetting (oil) fluids. We have also found large saturation fluctuations in the residual