Thin Liquid Films Containing Crude Oil Fractions with Different Structures—Emulsion Stability

Abstract

We report the influence of crude oil fractions on the stability of crude oil emulsions using an apparatus designed for bilayer lipid membrane studies. Two acid fractions were isolated from ShengLi crude oil, and they were characterized by elemental analysis, GPC, FTIR, H¹‐ and C¹³‐NMR, etc. These interfacially active components (IAC) also have been isolated from DaQing crude oil. Their structure/interfacial property relationships were studied by measuring liquid film lifetimes and dynamic interfacial tensions. It was found that the aliphatic acids with different structures in crude oil decrease the stability of thin liquid films to different degrees. The aliphatic acids with lower molecular weights can promote the rupture of the liquid film. The interfacially active components, which contain mainly asphaltenes, resins and waxes, lead to the formation of rigid films and increase film lifetimes. These results indicate that the structure of the natural active components in the oil phase, the alkali concentration, and the type of alkali have a great effect on the liquid film lifetimes.

Keywords:

• ShengLi acids
• Crude oil
• Structure analysis
• Lifetime of the film

Acknowledgments

Financial support by the National Key Basic Research Development program “Fundamental studies of the Extensively Enhanced Petroleum Recovery” (project Grant G199990225) is gratefully acknowledged.