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Observations on emulsion stability and interfacial properties in improved oil recovery by chemical flooding

Conference · · Prepr., Div. Pet. Chem., Am. Chem. Soc.; (United States)
OSTI ID:6708662

Mechanisms of spontaneous emulsification in petroleum sulfonate and caustic systems are described. Differences in behavior in surfactant and alkaline solutions were characterized by high speed cinephotomicrography. Results on the kinetics of coalescence of both the Long Beach and the Huntington Beach crude oil droplets in caustic systems are presented. The effects of interfacial tension, interfacial charge and interfacial viscosity on coalescence, and emulsion stability for crude oil emulsions in alkaline solutions have been assessed. It is concluded that for equilibrated systems there is no correlation between the interfacial tension or interfacial charge and emulsion stability. However, a direct qualitative correlation was found between the interfacial viscosity and the emulsion stability. It was observed that the NaOH concentration which yields higher interfacial shear viscosity also yields higher emulsion stability. Further data on the effect of interfacial viscosity on emulsion stability and its subsequent effect on oil recovery efficiency by alkaline waterflooding are needed. The maximum electrophoretic mobility or zeta potential corresponds to the minimum interfacial tension for the caustic systems containing 1% NaCl but this correlation is not valid for systems which do not contain NaCl. The interfacial tension between the crude oil and the alkaline solution is a strong function of the age of the interface. The interfacial tension increases with the age of the interface. The interference phase contrast technique combined with high resolution optical sectioning may be extended to measure the thickness of the film surrounding oil droplets in caustic systems. The film thickness and the molecular packing in the film need to be correlated with the stability of an emulsion system. Micellar aggregates with relatively large diameters were found for both the petroleum sulfonate and the caustic flooding systems. 36 references, 17 figs., 2 tables.

Research Organization:
Illinois Inst. of Tech., Chicago
OSTI ID:
6708662
Report Number(s):
CONF-780305-P1
Journal Information:
Prepr., Div. Pet. Chem., Am. Chem. Soc.; (United States), Journal Name: Prepr., Div. Pet. Chem., Am. Chem. Soc.; (United States) Vol. 23:2; ISSN ACPCA
Country of Publication:
United States
Language:
English