Research on the emulsifying ability of surfactants in crude oil

A novel colorimetric method to measure the emulsifying ability of surfactants for crude oil has been proposed. The emulsifying ability of five surfactants for two kinds of crude oil was determined at different temperatures and salinities. The oil-water interfacial tension, particle size distribution of emulsion, emulsion stability and ability of reducing viscosity by emulsifying were investigated at the corresponding condition. The results show that there is no correlation between emulsifying ability and HLB value of surfactants. The property of crude oil has a certain impact on the emulsifying ability, and the interfacial activity is the main influencing factor on it. The emulsifying ability is affected obviously by temperature. At first it increases and then it decreases with rising temperature. Inorganic salts of low concentration are beneficial to enhance the emulsifying ability. The emulsifying ability has negative correlation with the particle size of emulsion, and positive correlation with the ability of reducing viscosity by emulsifying. There is no inevitable relation between emulsifying ability and emulsion stability.