Effect of Nonionic Surface-active Substances on Paraffin Crystallization in the System

Presented are physicochemical and rheological properties of viscous paraffinic oils recovered from the south of West Siberia, Russia, Germany and Mongolia in the temperature range of 20-90 °C at different shear rates and interactions with oil-displacing systems based on surfactants and alkaline buffer solutions. The systems were determined to have demulsifying effect on the viscous paraffinic oils under study, regardless of surfactants composition and structure. Temperature dependence of paraffin crystallization point on a preheating temperature is extreme. At the same time maximum paraffin crystallization points correspond to preheating temperatures of 50-60 °C. We studied the ability of non-ionic surfactants – oxyethylated alkylphenols with different degrees of oxyethylation, from 12 to 90, to exhibit depressant properties with respect to paraffinic oils, reduce the viscosity of crude oils and the paraffin crystallization point. Optimal degree of oxyethylation of non-ionic surfactants was determined equal to 50, at which the decreases in oil viscosity and paraffin crystallization point were maximal. One can use the proposed compositions to develop EOR technologies for high-viscosity paraffinic oils.