Numerical Study of Viscous Fingering in Heterogeneous Porous Media

Abstract

The displacement of a fluid by a second immiscible fluid is a fundamental process which is relevant for many technological applications, particularly in the petroleum industry. Water is the fluid widely used to push oil to production wells. During this immiscible displacement, a viscous fingering instability appears at the water-oil interface. This undesirable phenomenon leads to a low oil sweeping efficiency. To prevent this situation, techniques called EOR (Enhance Oil Recovery) are used. These methods have technical, economic and environmental disadvantages. Therefore, the objective of this work is to seek a rational use of EOR techniques by determining the right place and the appropriate time to operate them. In many previous studies, the effects of viscosity ratio, interfacial tension and flow rate are investigated. In this study, we numerically investigate the effect of the heterogeneity of the medium and the presence of the fracture on this phenomenon. Three different configurations are studied. The obtained results allowed to locate the regions where the behaviour of the instability varies during displacement in the porous medium, regions where instability is increasing and others where it remains constant. a qualitative comparison between the different cases is also made.