Abstract: This paper studied the self-made organic oil soluble nickel salt as a catalyst by which the aquathermolysis reaction of heavy oil is conducted using high temperature autoclave, and investigates the effects of catalyst requirement, reaction temperature, reaction time and injected water on the heavy oil viscosity and group composition before and after such a reaction, and then selects the optimum reaction condition for the viscosity reduction. Based on this condition, the heavy oil element before and after that is analyzed. The results show that after 24 h reaction and adding 0.1wt% catalyst of organic acids nickel, the viscosity of heavy oil decreased distinctly at reaction temperature of 240℃ and additive water amount of 30wt% , with the decreases of Asphaltene content by 1.4wt% , colloid content by 5.0wt%, and the increases of aromatic content by 3.5wt% and saturated component content by 2.9wt%.

Key words: heavy oil, steam injection, aquathermolysis, catalysis, upgrading, viscosity reduction