Mechanistic Insights into Nanoparticle-Modified Polymer Flooding for Enhanced Oil Recovery

Area of Science:

• Petroleum Engineering
• Materials Science
• Colloid and Surface Chemistry

Background:

• Enhanced oil recovery (EOR) is crucial for maximizing hydrocarbon extraction.
• Nanosilica-modified polymers (MNPs) show promise for EOR but their microscopic mechanisms require detailed understanding.

Purpose of the Study:

• To elucidate the oil displacement mechanisms of synthesized nanosilica-modified polymer (MNSP).
• To evaluate the efficiency of MNSP in mobilizing residual crude oil.

Main Methods:

• Core flooding experiments were conducted to assess oil displacement efficiency.
• Microscopic visualization in etched models provided insights into mobilization mechanisms.
• Interfacial tension, emulsification efficiency, and wettability alteration were analyzed.

Main Results:

• MNSP achieved a high recovery ratio of 91.60%.
• Crude oil utilization was highest in large pores (65.00%), followed by medium (25.78%) and small pores (9.22%).
• The mechanism involves a synergistic network structure reducing interfacial tension, wettability reversal, and enhanced emulsion formation.

Conclusions:

• MNSP effectively mobilizes residual oil through a multi-faceted mechanism.
• Nanosilica plays a key role in interfacial tension reduction and wettability alteration.
• This research provides a theoretical basis for developing advanced polymer flooding agents.