Unstable miscible liquid—liquid displacement in porous media: A new model for predicting displacement performance in homogeneous beds

Abstract

A theory of fingering was developed to predict the volume of the mixing zone which is likely to result during an unstable miscible displacement in a homogeneous porous bed. This theory is based on the application of Darcy's Law to a simple model representing the flow situation, and the calculated energy dissipation within the model. Physical factors believed to govern the growth of fingers are considered: viscosity ratio, density difference, flow rate, medium porosity and permeability. The theory only considers flows in homogeneous beds. Available experimental data, those of this present work and of Slobod and Howlett, confirm the importance of the first three factors mentioned. The experimental study also found that the model is superior to a previous one of Koval in predicting mixing zone volumes of displacement processes involving both viscous fingering and gravity segregation. However, a method to extend the model to heterogeneous systems was not achieved.