Huntington Beach caustic

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. 

A series of experiments were conducted to determine the emulsion stability in caustic systems. Figures 6 and 7 show data for the kinetics of coalescence and hence emulsion stability for the crude oil from Huntington Beach (Lower Main Zone), California (oil gravity of 23°API and oil acid number of 0.65). Figure 6 shows data for a nonequilibrated system and for a very low concentration of NaOH (0.003%) and 1% NaCl. This emulsion is unstable. Figure 7 shows data for two different concentrations of... 

Figure 4. Drop-size distributions for Huntington Beach crude oil-caustic emulsions...

Figure 7. Kinetics of coalescence for equilibrated samples of Huntington Beach crude oil-caustic systems...

Figure 13 exhibits both interfacial tension and electrophoretic mobility for the Huntington Beach Field crude oil against sodium orthosilicate containing no sodium chloride. The interfacial tension values are observed to be higher for the non-equilibrated sample in this case than for the caustic system reported in Figure 12. The minimum interfacial tension of 0.01 dynes/cm occurs at about 0.2% sodium silicate as opposed to a value of less than 0.002 dyne/cm at about 0.06% NaOH. It is interesting to note, however, that the maximum electrophoretic mobility is the same for the two systems. Once again, it should be noted that a maximum in electrophoretic mobility does not correspond to a minimum in interfacial tension for those samples which contained no sodium chloride.

Figure 10. Effect of caustic concentration on electrophoretic mobility and interfacial tension of nonequilibrated sample of Huntington Beach crude...

Preliminary results on the kinetics of coalescence of both the Long Beach and the Huntington Beach crude oil droplets in caustic systems have been presented. 

Over the years, several field trials have been reported using caustic with limited success O, 9-13). More recently four alkaline field trials have been. started, employing specifically sodium orthosilicates. These include projects by THUMS at the Wilmington field, by Aminoil USA at the Huntington Beach Field and by Union in their Van and Orcutt Fields. 

Previous work (1) in core floods with the system, Huntington Beach Crude vs. 0.5% Na SiO plus 0.75% NaCl, showed channeling of the crude oil during the injection of the caustic slug (Figure 6). The channeling phenomena along with the fact that emulsions were not observed until after 95% of the recovered oil was produced, could have lead to lower oil recovery efficiencies. To... 

The crude oil system used for our work was the LMZ (Lower Main Zone) S-47 variety from Huntington Beach, California. This crude oil has an acid number of 0.65 mg KOH/gm sample which makes it particularly amenable to caustic flooding techniques. The bulk viscosity measured at room temperature was 108 cp. The API gravity for this crude oil is 23.5°. The standard caustic aqueous phase was 0.15% (wt) sodium orthosilicate plus 0.75% (wt) sodium chloride in double distilled water. At this concentration, the aqueous phase has a pH of 11.7. 

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