Sulfonate systems, spontaneous emulsification

As in the previous study (4), the experiments involve brine-alcohol-petroleum sulfonate mixtures brought into contact with oil. In these systems, which are the type used for enhanced oil recovery, the initial mixtures are, depending on the salinity, either stable dispersions of lamellar liquid crystal and brine or a single liquid crystalline phase. The latter is formed at higher salinities than the former, in accordance with the general pattern of phase behavior in such systems described elsewhere ( 5). Indeed, one aspect of our work which differs from studies made by others of spontaneous emulsification in enhanced oil recovery processes (6-7) is emphasis on the need to understand the role of liquid crystals in the overall nonequilibrium process. Related studies of spontaneous emulsification in other systems are reviewed elsewhere... 

In this paper we report first the spontaneous emulsification mechanisms in the petroleum sulfonate and caustic systems. This is followed by the kinetics of coalescence in alkaline systems for both the Thums Long Beach (heavy) crude oil and the Huntington Beach (less viscous) crude oil. Measurements of interfacial viscosity, interfacial tension, interfacial charge and micellar aggregate distributions are presented. Interrelationships between these properties and coalescence rates have been established. 

Spontaneous Emulsification Mechanisms in Sulfonate and Caustic Systems... 

The spontaneous emulsification mechanisms were determined for the 3% (Active) Petrostep 420 and 1.5% NaCl and 0.58% n-hexanol versus non-pre-equilibrated Salem crude oil (Sulfonate System). The mechanisms were also determined for Thums Long Beach Crude Oil (Well 108 B) versus 0.05 M (0.2% by weight)... 

Therefore, the mechanism of spontaneous emulsification in the caustic system is interfacial turbulence. The mechanisms for the sulfonate system are diffusion and stranding. 

The mechanisms of a spontaneous emulsification in petroleum sulfonate and caustic systems have been described. 

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