Oil Sands Steam-Assisted Gravity Drainage Process Water Sample Aging during Long-Term Storage

Technology development activities are routinely performed using process water samples collected and stored for several months while tests are being conducted. The results of the technology development activities are highly correlated to the water composition and properties. Processes such as atmospheric oxygen contamination, microbiological activity, and ultraviolet (UV) oxidation have the potential to act on a sample during long-term storage and modify the properties that may be relevant to technology development testing. These changes are referred to as aging. Process water samples collected from a steam-assisted gravity drainage (SAGD) bitumen production plant were subjected to different storage conditions and monitored for nearly 5 months. The sample organic composition and physical characteristics of the water were found to be highly dependent upon storage conditions, particularly atmospheric oxygen exposure. Oxygen exposure appeared to drive abiotic polymerization and precipitation of phenolic species and promote aerobic microbiological activity. These results highlight the importance of excluding oxygen from the sample during collection and storage activities. Sample aging must be accounted for in technology development testing activities.