Chapter 5
5.9. Asphaltene content of solid in different layers of emulsion
5.9.1. Materials and methods
Demulsifier 6057 was from Syncrude. Ltd. Solids in different layers emulsion
were collected by centrifugation at 8000 g for 30 minutes. After centrifugation, oil
and water were removed and the open centrifuge tube was put in the oven at 50
0C overnight until the weight did not change. Then the separated clay was treated
with toluene several times until the supernatant toluene layer was colorless and
transparent. Toluene was separated by centrifugation at 8000 g for 30 minutes.
After drying, weight difference of solid before and after toluene treatment could be
obtained. Asphaltene content in solid was calculated based on weight difference
of solid and the total weight of solid before toluene treatment.
5.9.2. Results and discussions
Table 5.7 shows solid distribution and asphaltene content of solid in different
layers of partially separated emulsions with 200 ppm 6057 24 hours after sample
preparation at 80 0C. The pH of the aqueous phase without silicate is 8.3. The pH
ofthe aqueous phase with 4×10'4 M silicate is 9.1.
From all the samples, clay solid has asphaltene content: in oil layer > in rag
layer > at bottom layer. Clay solid in emulsion sample has oil-wet sequence: in oil
layer > in rag layer > at bottom layer. The reason could be that solid with higher
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