Abstract: Aiming at the difficulty in demulsification of shale oil, the componentsof shale oil emulsion was analyzed, and the stabilization mechanism was studied.It was found that asphaltenes and fracturing fluid components are important factors influencing emulsion stability. A demulsifier RPD(SL) for shale oil emulsions was developed and the demulsification evaluation tests were conducted.Compared with on-site agents, the dehydration effect is improved by more than 50%.Molecular simulation studies on the rupture mechanism of interfacial films have found that the addition of demulsifiers can significantly weaken the stability of asphaltene and resin interfacial films, and reduce the interaction energy between the interfacial active components and water molecules, thereby causing them to desorb at the oil-water interface and ultimately achieving demulsification.The synthesized demulsifier was field-tested at a SINOPEC oilfield gathering station.The results show that after addition of the new demulsifier, the water content in shale oil dropped significantly.The demulsifier has also been verified to efficiently treat initial production fluids, making it suitable for different development stages and demonstrating high treatment efficiency for both high-water-cut and low-water-cut oils.

Key words: shale oil, asphaltenes, resins, interfacial film, demulsification, hydrogen bond