Thermal cracking, aquathermolysis, and their upgrading effects of Mackay River oil sand

Abstract

Although various thermal technologies have been used in its oil recovery, including SAGD, there have been few studies on systematical analyzing the cracking behaviors of Mackay River oil sand. In the present work, a series of thermal cracking and aquathermolysis reactions have been carried out at different temperatures for different times. The viscosity, API°, SARA contents, elemental contents, and average relative molecular weights of cracked oil samples, as well as the gas product compositions have been analyzed to characterize the reaction performance of oil sand. The results showed that the aquathermolysis was superior to thermal cracking on the viscosity reduction and quality upgrading of the oil sand, and the thermal cracking of oil sand took place at 250 °C, while the cracking reactions took place at 200 °C in aquathermolysis. The viscosity reduction and API° enhancements depended on the changes of the oil sand molecular structures and its components. Besides, we have obtained fitted equations of the viscosity reduction ratio to the reaction temperature, by which the viscosity reduction effects of the oil sand could be predicted. Moreover, the gas compositions can be used to monitor the cracking performance of the oil sand in thermal cracking and aquathermolysis.