Enhanced Oil Recovery Mechanism of Limonene Nanoemulsion-based Oil Recovery Agent in Reservoirs

Combined with experiment and theoretical calculation, the assembly structure and stability of nanoemulsion were analyzed. Through structural optimization of energy minimization and molecular dynamics simulation, the behavior of limonene nanoemulsion in asphaltene and resin of reservoir was investigated, and the stimulation mechanism of limonene nanoemulsion oil displacement agent was discussed. The results indicate that the strong hydrophobicity and non-planar structure of limonene molecules play a crucial role in the oil recovery process. Its hydrophobic properties promote the surfactant to assemble into highly stable and small-sized nano-micelles, thus effectively reducing the adsorption loss of the stratum to the nanoemulsion in the reservoir and expanding the sweep volume. Additionally, the non-planar structure of limonene allows it to rotate flexibly during irregular molecular collisions, enabling deep penetration into the asphaltene and resin within heavy oil. Through π—π interactions, limonene disrupts the aggregation of these components, reducing the viscosity of heavy oil, enhancing fluidity and detachment properties, and thereby significantly improving oil recovery rates. These findings offer new insights into the enhanced oil recovery mechanisms of nanoemulsion-based agents and provide important references for the development of more efficient nanoemulsion-based oil recovery agents.