Study On Aquathermolysis Catalyst System For Heavy Oil Under Steam Injection Assisted By Chemical Conditions

The traditional technique of heavy oil exploitation is extract oil by steam injection recently. But the technique just reduces viscosity temporarily and has other faults like lower heat utilization and poor recovery ratio. In view of these problems, this paper proposes a new technique that extracting oil assisted by aquathermolysis under steam injection conditions. This technique injects aquathermolysis catalyst system when steam injection, and let heavy oil act a series of chemical reaction, then causes some heavy components of oil to generate splitting, reduces the viscosity inconvertiblly and upgrades the heavy oil in layer and enhanced oil recovery.This paper chiefly studies on aquathermolysis catalyst system by experimental research and proceeds field application. First of all, a oil soluble catalyst is synthetised, and its preferred reaction conditions is optimized by orthogonal experiment and single factor experiment: reaction temperature is 240℃, reaction time is 30h, mass fraction of catalyst is 0.3wt%, mass fraction of water is 30wt%. Under these conditions, the reducing viscosity ratio of heavy oil can reach to 80.1%. Based on the oil soluble catalyst research, the effect of reducing viscosity of catalyst cooperate with hydrogen donor and auxiliary is researched in detail. A aquathermolysis catalyst system is fixed: 0.3wt% catalyst & 0.05wt% hydrogen donor & 0.3wt% auxiliary. Under the effect of this system, the reducing viscosity ratio of heavy oil can reach to 87.4%. At the same time, the component change of oil, gas and water after the reaction of aquathermolysis with catalyst system is researched. The result indicates that main break happens on C-S bond of heavy oil of Gudong, besides, some C=O bond and C-C bond also cracked, then causes that the content of satisfied hydrocarbon and aromatic hydrocarbon increases, the content of S element decreases obviously, and H/C increases. At last, application of steam stimulation assited by aquathermolysis with catalyst system is proceeded at Gudong oil field, and preferable effects of reducing viscosity and increasing production are acquired: the average reducing viscosity ratio comes to 80% after well startup beginning, and close to 60% after well startup 100 days; the average stimulate is 2.7 per day of single well and total increasing production is 3349.1 t in one throughput cycle.The research of laboratory experiment of aquathermolysis catalyst system provides theoretical foundation for design of field testing scheme, the results of tests indicate that this technique have a favourable applied value and development foreground at Gudong oil field.