Study on the Influence Factors of Demulsifier on Oil-Water Interface

Abstract

Natural surfactants such as gum and asphaltene in crude oil can form stable emulsions. Emulsions can cause significantly harm to crude oil storage, processing, product quality and equipment. Therefore, oilfield crude oil must undergo demulsification before being exported. However, conventional demulsifiers are difficult to dehydrate at low temperatures and the mechanism of action of low-temperature demulsifiers on oil-water interfaces is not clear.Therefore, this paper focused on the three low-temperature demulsifiers AR101, AR902, and AE405 selected from the Y block in X region, and used the interfacial rheological system of the interfacial tension meter to explore the low-temperature demulsification mechanism from the changes in oil-water interfacial tension. The results indicate that interfacial tension has a certain impact on crude oil demulsification, and the lower the interfacial tension value, the better the demulsification effect. As the concentration of the demulsifier increases, the interfacial tension value first decreases and then remains stable, indicating the existence of an optimal concentration that minimizes the interfacial tension. As the demulsification temperature increases, the interfacial tension between oil and water decreases, and the time required to reach stability becomes shorter, resulting in faster demulsification speed and better effectiveness. By studying the mechanism of low-temperature demulsification, theoretical guidance is provided for the on-site application of demulsifiers in oil fields.