Effect of sodium hydroxide on interfacial rheological properties of oil-water systems

摘要

Interfacial rheological properties of a model crude oil-water system were studied in the presence of sodium hydroxide. The interfacial viscosity, the non-Newtonian flow behaviour and the activation energy of viscous flow were determined as a function of shear rate, alkali concentration and aging time. The fundamental conclusion of the experimental results is that the interfacial viscosity drastically decreases in the presence of sodium hydroxide and the change under favorable conditions may exceed three or four orders of magnitude. Simultaneously, the sodium hydroxide effectively suppresses the non-Newtonian flow behaviour of the interfacial layer. The experimental observations are explained by simultaneous chemical processes taking place in the boundary layer. The present data may contribute to elucidate the formation, stability and break of alkali-containing oil-water emulsions and they provide additional information to better understanding of the displacement mechanism and formulation of the alkaline flooding being as a prospectful chemical enhanced oil recovery method.