Viscous Fingering Dynamics in Porous Media

Viscous fingering is a fluid–fluid instability that arises when a less viscous fluid displaces a more viscous one in a porous matrix. The resulting finger-like patterns compromise sweep efficiency in applications ranging from enhanced oil recovery to groundwater remediation and carbon sequestration. At pore scale, the interplay between viscous forces, capillary forces and pore geometry sets the onset and growth of fingers. A high mobility ratio amplifies perturbations at the advancing front, while heterogeneity in permeability can either suppress or accentuate fingering by locally altering pore-scale flow paths. Recent advances have focused on active control strategies, novel cell geometries and pore-scale numerical methods to predict and manage fingering. Understanding the transition from stable displacement to complex finger networks remains a central challenge. By combining experimental studies in analogue systems with high-fidelity simulations, researchers have begun to map out stability regimes, identify scaling laws governing finger width and growth rate, and propose design principles for mitigating adverse effects in practical systems.

Research from Nature Portfolio

Recent studies have demonstrated active control of the fingering instability by coupling electro-osmotic flows with hydraulic pressure in a narrow-gap cell. By applying an external electric field along the confining surfaces, induced secondary flows can assist or oppose the bulk displacement, effectively modulating local flow resistance and delaying or accelerating finger onset. The proposed mechanism of electrokinetic thinning and thickening offers a tunable approach to interface stabilisation without altering fluid viscosities or channel geometry. In parallel, alternative cell designs employing multiple injection ports have been introduced to engineer ordered, multiscale networks of fingers. By varying the number and location of source holes, researchers have achieved reproducible fractal-like patterns and controlled branched structures over a wide range of scales. This multiport approach paves the way for fabricating bespoke fluidic architectures and for systematic exploration of nonlinear interactions between neighbouring fingers.

Viscous Fingering Dynamics in Porous Media publication trend

The graph below shows the total number of articles in viscous fingering dynamics in porous media across all publications each year (not limited to Nature Index journals).

Technical terms

Viscous fingering: The growth of finger-like patterns at the interface when a less viscous fluid displaces a more viscous one in a porous or confined geometry.

Porous media: A solid matrix containing interconnected voids through which fluids can flow under pressure.

Mobility ratio: The ratio of displacing fluid mobility to displaced fluid mobility; a key parameter determining stability of the interface.

Fractional flow: The proportion of the total volumetric flow rate carried by one phase in a multiphase displacement.

Hele-Shaw cell: A model system comprising two closely spaced parallel plates used to study interfacial instabilities in a quasi-two-dimensional flow.

References

1. Active control of viscous fingering using electric fields. Nature Communications (2019).
2. Viscous Fingering in Multiport Hele Shaw Cell for Controlled Shaping of Fluids. Scientific Reports (2017).
3. On the Modelling of Immiscible Viscous Fingering in Two-Phase Flow in Porous Media. Transport in Porous Media (2020).
4. Pore-scale simulation of miscible viscous fingering with dissolution reaction in porous media. Physics of Fluids (2021).
5. Experimental and computational advances on the study of Viscous Fingering: An umbrella review. Heliyon (2021).