Study Of Viscosity Reduction On Catalytic Aquathermolysis Of Shengli Heavy Oil

Catalytic aquathermolysis of heavy oil is an oil recovery technique, which injectsappropriate catalysts and additives with steam into the reservoir, makes the heavy oil crackingin the high temperature steam conditions, thus changing the molecular structure of heavycomponents, reducing the acting force between oil molecules, lowering heavy oil viscosityirreversible. Compared with other heavy oil recovery technology, this technology has obviouseconomic benefits and good application prospect, and has become a hot research topic.In this paper, we focus on GD2-25, GDN34P2, Shan56-9×11three heavy oils andstudying the relationship between the viscosity of heavy oil and its fractions.Through thecatalyst influencing on viscosity reduction rate, the better catalyst is selected, and thenacquires the optimum experimental conditions of the reaction. The physical and chemicalproperties of heavy oil and its resin, asphaltene are researched both before and after reactionby molecular weight analysis, element analysis, nuclear magnetic resonance and otherinstruments.The research results indicate that the resin and asphaltene are the key components ofheavy oil, and the viscosity of heavy oil increases with the content of resin and asphaltene.The optimum experimental conditions of the best catalyst is: catalyst dosage1%, temperature240℃, reaction time24h, and the amount of water30%. The viscosity reduction rates ofheavy oils are45.85%,47.63%,54.86%through catalytic aquathermolysis reaction. Thecracking components of Shengli heavy oil is mainly resin, and it occurred both cracking andpolymerization in the reaction process, but cracking is the mainly reaction. The relativemolecular mass, aromatic carbon rate, aromatic ring number and sulfur, nitrogen contentdecreased, and condensation degree parameter, index of branched carbon chain and atomicratio of hydrogen to carbon increased after reaction of heavy oil and its resin andasphaltene.The hydrogenation, ring-opening, chain breakage, sulfur removal and otherreaction are taken place in the reaction process. The DBE values of O2, O3, N1and otherheteroatom compounds decreased after the reaction, large molecules cracking into smaller molecules, and produced CH4, CO2, H2and other small molecular non-condensable gas. Themolecular structure has become looser, promoted the viscosity reducing of heavy oil andimproved oil property.