Fate of Organic Liquid-Crystal Domains during Steam-Assisted Gravity Drainage/Cyclic Steam Stimulation Production of Heavy Oils and Bitumen

摘要

The fate and impacts of hydrocarbon-based amphotropic liquid-crystal-rich domains (a recently identified material class found in hydrocarbon resources) during production transport and refining are unknown. New materials and process knowledge on this topic will contribute to parsing impacts currently attributed to asphaltenes or other crude oil fractions. In this qualitative work, the fate of liquid-crystal-rich domains in steam-assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS) production environments is surveyed, using a combined laboratory and field study. In the laboratory, a fraction of liquid crystal -rich domains present in Athabasca bitumen is shown to transfer to the water-rich phase under simulated SAGD and CSS conditions and transfer mechanisms are discussed. In the field study, liquid-crystal-rich domain transfer from Peace River and Athabasca bitumen to process water during SAGD production is demonstrated. Transferred liquid-crystal-rich domains are subsequently captured in surface facilities (primary separation, secondary separation, and water treatment processes) and do not impact steam generator operation, under normal operating conditions. Most of the liquid-crystal-rich domains are returned to the hydrocarbon-rich phase during primary separation. Impacts of liquid-crystal-rich domains on hydrocarbon resource transport and refining and SAGD surface facility optimization comprise foci for future study.