Three-Dimensional Interaction of Viscous Fingering and Gravitational Segregation in Porous Media

Abstract

Viscous fingering is fluid dynamics instability induced on the displacement front when a less viscous fluid (LVF) displaces a more viscous fluid (MVF), thereby reducing the displacement efficiency. The displacement of a denser fluid by a less dense fluid produces a gravitational tongue. This gravitational segregation also reduces the displacement efficiency. In this study, the three-dimensional structure of the fingering pattern at the viscous fingering to gravitational segregation boundary was examined using X-ray microtomography on a packed bed of particles. At low gravity numbers, viscous fingering resembled that without gravity characterized by nonlinear interaction including tip-splitting, shielding, and coalescence. At intermediate gravity numbers, viscous fingering is associated with the gravitational tongue due to segregation. At high gravity numbers, a clear gravitational tongue penetrates from the inlet to the outlet. Consequently, the concentration near the injection point decreases and exhibits a flat profile in the flow direction. The displacement efficiency decreases with increasing gravity number, with the highest value achieved without gravity but depends on many factors, including the viscosity ratio and Péclet number.

Influence of Injection Rate and Oil Viscosity on Viscous Fingering – Simulation Prediction

“…This phenomenon is expected since the minimal or nonexistence of residual oil behind the waterflood front. This observation agrees with study done by Suekane et al, [19] who concluded that viscous fingering could affect the waterflooding efficiency.…”

“…Viscous fingering can affect sweep efficiency which one of the investigations to predict its effect towards the oil recovery rate. A study done by Suekane et al, [19] showed that viscous fingering can reduce the displacement efficiency. They observed several factors viscous fingering occurred because of viscosity ratio, Péclet number, and gravity number.…”

Horizontal miscible displacements through porous media: the interplay between viscous fingering and gravity segregation

“…In a similar vein, a number of authors have looked at the effect of gravity on the viscous-fingering instability: Rogerson & Meiburg (1993b) studied the onset of the viscous-fingering instability with a gravitationally driven shear parallel to the interface using linear stability analysis; Rogerson & Meiburg (1993a), Tchelepi et al (2004), Tchelepi & Orr (1994), , Camhi, Meiburg & Ruith (2000) and Riaz & Meiburg (2003) investigated the nonlinear evolution of the fingering instability using numerical simulations; and Tchelepi & Orr (1994), Berg et al (2010) and Suekane, Koe & Barbancho (2019) examined the nonlinear evolution of the fingering instability using laboratory experiments. While these studies highlight some of the interesting qualitative behaviour that can be observed, they do not provide a full overview of the different dynamical regimes, nor do they provide quantitative predictions for the evolution of the concentration field.…”

“…(2004), Tchelepi & Orr (1994), Ruith & Meiburg (2000), Camhi, Meiburg & Ruith (2000) and Riaz & Meiburg (2003) investigated the nonlinear evolution of the fingering instability using numerical simulations; and Tchelepi & Orr (1994), Berg et al. (2010) and Suekane, Koe & Barbancho (2019) examined the nonlinear evolution of the fingering instability using laboratory experiments. While these studies highlight some of the interesting qualitative behaviour that can be observed, they do not provide a full overview of the different dynamical regimes, nor do they provide quantitative predictions for the evolution of the concentration field.…”

Instability Problems and Density-Driven Convection in Saturated Porous Media Linking to Hydrogeology: A Review

“…In [118,119], the same method of X-ray computed tomography was used for investigating the interplay between viscous and gravitational fingering observed in vertical miscible displacement under the gravity force in three-dimensional porous media. In particular, the experiments exhibit that, in conditionally stable configurations (when the viscosity contrast and density contrast have a different effect on the interface, so that one of them stabilizes it while the other destabilizes it), the crossover between the stable and unstable displacements exists, depending on the injection velocity.…”