STUDY ON THE INFLUENCING FACTORS OF DEMULSIFIER ON THE OIL-WATER INTERFACE VISCOELASTICITY

Water flooding is a commonly used development method in oilfields, and the water cut of the output fluid of oil wells gradually increases with the increase of injected water in water wells. Due to the presence of natural surfactants such as gum, asphaltene and organic acid in crude oil, it is easy to form a high strength viscoelastic oilwater interfacial film and a stable emulsion. To facilitate the storage and transportation of crude oil, it is necessary to demulsify the crude oil emulsion. In this paper, the CQ crude oil was taken as the research object, and the effects of demulsifier type, concentration, demulsifier temperature and oil-water properties on the viscoelasticity of oil-water interfacial film were investigated by using rheometer and then the demulsification mechanism was explored. The results show that the lower the interfacial film strength, the better the demulsifier. In addition, with the increase of demulsifier concentration and temperature, the oil-water interfacial viscoelasticity decreases and the interfacial film strength further decreases. In general, the demulsification effect will be significantly improved with the increase of demulsifier concentration and temperature, and the dehydration effect will be better. The research results can provide theoretical guidance for the field application of demulsification.

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