Abstract: The influence of deasphaltene oil, resin, asphaltene and resin-asphaltene mixture on the interfacial property of Gudao heavy oil in water emulsions was investigated. The results showed that asphaltene component having high aromatic carbon, low alkyl carbon and high aromatic condensation index exhibited high interfacial activity. During the formation of oil in water emulsions, the existence of aromatic component in deasphaltene oil enhanced the solubility of resin, so the interfacial activity of deasphaltene oil is higher than that of resin and asphaltene. The dispersion of asphaltene in simulated oil was enhanced by the existence of resin, in such case the solubility of asphaltene increased, the asphaltene molecule existed as free molecule, and all of its functional groups could reach the interface easily, thus the interfacial tension of oil and water reduced. Results also indicated that a positive synergetic effect existed between anionic emulsifier LAS and heavy oil components, yet negative synergetic effect was observed between non-ionic emulsifier OP-10 and heavy oil components. The formation of stable oil in water emulsions was due to the interaction among all the heavy oil components and emulsifiers

Key words: resin, asphaltene, deasphaltene oil, emulsifier