Effect of Nanoscale Surface Textures on Multiphase Flow Dynamics in Capillaries

Area of Science:

• Environmental science
• Fluid dynamics
• Materials science

Background:

• Multiphase flow in porous media is crucial for applications like enhanced oil recovery and CO2 storage.
• Existing models may overlook nanoscale surface textures, affecting flow predictions.
• Understanding microscale dynamics is key to improving macroscale flow processes.

Purpose of the Study:

• To investigate the impact of surface roughness and wettability on multiphase flow dynamics.
• To characterize the role of nanoscale surface textures in porous media flow.
• To develop improved models for predicting flow behavior.

Main Methods:

• Conducted spontaneous and forced imbibition experiments using modified glass capillaries.
• Measured dynamic contact angle and interfacial speed deviation under stick-slip flow conditions.
• Employed a 2^k factorial experimental design to analyze various influencing factors.

Main Results:

• Surface roughness and ionic strength significantly control dynamic contact angle in porous media.
• Nanoscale textures have a greater impact on flow dynamics than chemical wettability.
• A water film's interaction with roughness and chemistry significantly affects dynamic contact angle.

Conclusions:

• Extended Joos and Wenzel equations to include roughness, water film, and water chemistry.
• Developed a new empirical equation that improves prediction accuracy by up to 50%.
• Highlighted the critical role of nanoscale surface features in multiphase flow modeling.