Pore-Network Invasion: Understanding Fluid Displacement in…

What is Pore-Network Invasion?

Pore-network invasion refers to the process by which one fluid displaces another within a porous medium, such as soil or rock. This phenomenon is governed by the interplay between capillary forces and viscous forces.

In this simulation, you can observe how changing parameters like the capillary number (a dimensionless quantity that compares capillary force to viscous force) and viscosity ratio influences the displacement pattern of fluids.

The Role of Capillary vs. Viscous Fingering

Capillary fingering occurs when a less viscous fluid displaces a more viscous one, leading to unstable patterns and sharp fronts that can penetrate the displaced fluid. This is due to the surface tension forces acting at the interface between the fluids.

Viscous fingering, on the other hand, happens when a denser (more viscous) fluid displaces a less dense (less viscous) one, resulting in stable patterns with smooth interfaces. The displacement process here is dominated by viscous forces rather than surface tension.

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Lenormand's Phase Diagram

Lenormand's phase diagram categorizes the different regimes of fluid displacement based on the capillary number and viscosity ratio. This diagram helps predict whether capillary or viscous fingering will occur, as well as stable displacement.

The simulation allows you to explore these regimes by adjusting the sliders for capillary number and viscosity ratio, demonstrating how changes in these parameters affect the observed patterns.

Real-World Applications

Understanding pore-network invasion is essential in fields like petroleum engineering, where it influences oil recovery methods. In environmental science, it plays a role in groundwater management and contaminant transport.

Additionally, the principles of fluid displacement are relevant to biological systems, such as the movement of fluids within plant roots or the dynamics of blood flow in capillaries.

Frequently asked questions

What is a capillary number?

The capillary number (Ca) is a dimensionless quantity that compares the viscous forces to surface tension forces. It helps predict whether fluid displacement will be dominated by capillary or viscous effects.

Why does pore-throat disorder matter in this simulation?

Pore-throat disorder refers to variations in the size and shape of pores and throats within the porous medium. It affects how fluids move through the network, influencing the patterns observed during invasion.

How do changes in injection rate affect fluid displacement?

Increasing the injection rate can alter the dynamics of fluid displacement by affecting the pressure gradient driving the flow, which in turn influences whether capillary or viscous fingering occurs.

What is the significance of stable displacement in this context?

Stable displacement refers to a scenario where fluids move smoothly without forming sharp interfaces. This regime is significant for efficient fluid recovery and minimizing unwanted side effects, such as contamination or damage to the porous medium.

Try it live

Everything above runs in your browser — open Pore-Network Invasion: Capillary vs. Viscous Fingering and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

▶ Open Pore-Network Invasion: Capillary vs. Viscous Fingering simulation

Pore-Network Invasion: Understanding Fluid Displacement in Porous Media