Chapter 3
From water fraction profiles, it is easy to see the sample has three layers. On
the top, water fraction is zero, which corresponds to clean oil layer. In the middle,
water fraction is around 0.5, which corresponds to a water-in-oil emulsion layer. At
the bottom, water fraction is between 0.5 and 1.0, which corresponds to a
concentrated water-in-oil emulsion layer. The step changes of the water fraction
correspond to the fronts between layers.
In the calculation of sample 2 (with solids and PR5, Figure 3.19), T↑ for bulk
water, oil and emulsified water are 2.60 s, 0.63 s and 1.46 s, respectively. Besides
sedimentation, coalescence occurs at the same time. The sample with PR5 can
achieve more complete separation than that without PR5. Hence, on the top, the
signal amplitude is close to that of pure oil, at the bottom the signal amplitude is
close to that of bulk water. These results correspond to the results in Figure 3.15,
in which on the top is pure oil, in the middle is an emulsion layer, and at the
bottom is mostly separated free water. Emulsified water 7^ι values of samples 1
and 2 are very similar, which shows consistency of the mixing process with given
oil and water phases and indicates that the small amount of demulsifier in sample
2 does not significantly affect emulsified water Ti values.
In the calculation of sample 3 (no solids, no PR5, Figure 3.20), T↑ for bulk
water, oil and emulsified water are 2.60 s, 0.63 s and 1.11 s, respectively. The
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