On Organic Liquid Crystal Transfer from Bitumen-Rich to Water-Rich Phases: A Combined Laboratory and SAGD Field Study

Hydrocarbon-based liquid-crystal domains were observed in unreacted heavy fractions extracted from Athabasca bitumen and bitumen derived hydrocarbon resource fractions. Transfer of these organic crystalline domains to the water-rich phase during SAGD production is explored here because there removal, required for optimal operation of boilers used for water recycling, is unlike the removal of oil drops and dissolved oil from the water phase and their fate in water recycling processes is unknown. In this work, a fraction of these liquid-crystal rich domains present initially in bitumen are shown to be transferred to the water-rich phase in both laboratory experiments and industrial SAGD production facilities and possible transfer mechanisms are discussed. Tracing the fate of the liquid crystal domains in SAGD surface facilities revealed that SAGD water treatment processes eliminate liquid crystals from the water rich phase, during normal operation, as liquid crystals were not detected in the feed stream to the steam generator. The roles played by chemical additives, and their presence, comprise uncontrolled variables in the field study. Future work will focus on the individual unit operations of the water de-oiling and treatment process at a single facility to determine where and how the liquid crystals are eliminated from the produced water during normal operation. An approach for preparing liquid-crystal enriched samples is also proposed.