Microscopic Particle Image Velocimetry Analysis of Multiphase Flow in a Porous Media Micromodel

Area of Science:

• Petroleum Engineering
• Fluid Dynamics
• Materials Science

Background:

• Understanding pore-scale fluid flow is crucial for enhanced oil recovery.
• Porous media properties significantly influence displacement efficiency.
• Microscopic Particle Image Velocimetry (μPIV) offers high-resolution insights into fluid dynamics.

Purpose of the Study:

• To investigate pore-scale oil displacement behavior in engineered porous media.
• To analyze the impact of varying porosity and flow rates on water-oil displacement.
• To develop a mass conservation model for predicting displacement efficiency.

Main Methods:

• Fabrication of porous media micromodels with ordered cylindrical pillars (50% and 70% porosity) using photolithography.
• Performing oil displacement experiments by injecting water at controlled flow rates (37.5–150 μL/h).
• Utilizing μPIV to capture flow fields and constructing probability density functions (PDFs) of transverse velocity.

Main Results:

• Water preferentially follows paths of least resistance, displacing oil.
• μPIV-derived PDFs showed initial transverse velocity peaks that broadened and then retracted to zero, indicating equilibrium.
• Peak displacement efficiency was observed around 9 pore volumes in 50% porosity and 4 pore volumes in 70% porosity models.

Conclusions:

• Pore-scale displacement dynamics are strongly dependent on media porosity.
• A mass conservation model effectively describes displacement efficiency.
• Optimized porous media design can enhance oil recovery efficiency by reducing the required injected fluid volume.