Synergistic Influence of Heating Effects and Asphaltene–Resin–Wax Composition on the Emulsification Behavior of Crude Oil

This study investigates the emulsification behavior of BZ crude oil under the combined influence of component ratios and heating effects. Emulsification experiments show that the internal phase inversion point of BZ crude oil increases from 55% at 85 °C to 70% under the heating-effect conditions, which can be attributed to strengthened interfacial film formation and enhanced coverage of surface-active components. At 85 °C, the emulsion viscosity reaches a maximum of 52.4 mPa s at a 55% water cut, while the heating effect further increases the emulsion volume by 10.5 mL at a water cut of 70%. Simulated oils with varying asphaltene, resin, and wax compositions reveal that the optimal ratio of 1:5:9 (arw159) yields the highest internal phase inversion point: 80% at 30 °C, 60% at 85 °C, and 75% under the heating-effect conditions. Across all simulated oils, the heating effect consistently enhances viscosity and increases the inversion point. Asphaltene dispersion analysis shows that heating promotes the formation of more abundant and larger asphaltene aggregates. Dynamic interfacial tension measurements further demonstrate a significant reduction in interfacial tension under heating conditions, with asphaltene adsorption exhibiting a clear three-stage kinetic behavior. High-temperature, high-pressure drop-shape analysis confirms that the interfacial complex modulus increases under the heating effect, with arw159 presenting the highest value of 25.52 mN/m. Overall, these findings highlight the synergistic roles of the heating effect and component ratios in enhancing emulsification performance and interfacial properties. By elucidating the key factors and mechanisms governing crude-oil emulsification, this work provides valuable theoretical guidance for emulsifier design and optimization, thereby contributing to the advancement of petroleum engineering practices.