Distribution of oil sands formation water in bitumen froth

  • Author / Creator
    Jia, Bei
  • Bitumen froth from oil sands extraction typically contains 60 wt.% bitumen, 30 wt.% water, and 10 wt.% solids. To meet downstream process specifications, the water and solids in bitumen froth have to be removed. The objective of this study is to identify the source of the water reporting to the bitumen froth. The water comes from two sources: formation water contained in mined oil sands ore, about 3-7 wt.%; and processing water added during the extraction process to recover bitumen from oil sands. Determining the distribution of the formation water will enable us to go one step further to understand the effect of formation water on water removal from bitumen froth.
    After Denver Cell flotation process, the electrical conductivity of the emulsified water, free water and tailings water was determined. The results showed that the conductivity of emulsified water was higher than other water samples, indicating that high salinity formation water preferentially reported to the bitumen froth.
    To better differentiate distribution of formation water among various process streams, oil sands extraction was carried out using heavy water instead of normal water as processing water, the density of collected water samples was measured by high precision density meter. However, no conclusive result could be obtained by this method.
    To obtain more accurate quantification of formation water distribution, cobalt as chemical tracer was introduced in the processing water. Following the same procedure of oil sands extraction and water samples collection as in conductivity measurement and heavy water density measurement, the concentration of cobalt in various product streams was determined accurately by Atomic-Absorption spectroscopy. The percent of formation water in emulsified water was then calculated.
    To understand formation water distribution in the context of oil sands ore characteristics, different types of ores were tested. The results showed that the characteristics of an oil sands ore were decisive factor determining formation water distribution. It appeared that preferential distribution of formation water in the bitumen froth was detrimental to froth treatment.

  • Subjects / Keywords
  • Graduation date
    Spring 2010
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
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