Experimental study on viscosity reduction of heavy oil with water content by synergistic effect of microwave and nano-catalyst

With the depleting of conventional oil and gas resources, viscosity reduction of heavy oil became more and more important as a research focus. As a new method of viscosity reduction, the mechanism of microwave-assisted with nano-catalysts is still unclear. In this paper, the viscosity reduction of nano-catalyst and microwave treatment of heavy oil in different water content was studied. The experimental results showed that the maximum viscosity reduction was 96.81 % when the water content was 50 wt% under the conditions of microwave heating power of 614w, microwave heating temperature of 68 °C and nickel nano-catalyst concentration of 0.8 wt%. The oil samples before and after three treatments were analyzed by infrared spectroscopy, element analysis, four-component separation, and two-dimensional gas chromatography-mass spectrometry. By analyzing the changes of functional group, element composition, and component content, the effects of microwave and nano-catalyst were studied. The results showed that the resin and asphaltene content decreased by 17.3 wt%, and the hydrogen to carbon ratio was 2.14 when the water content was 30 wt% under the conditions of microwave heating power of 666w, microwave heating temperature of 65 °C and nickel nano-catalyst concentration of 2.3 wt%, which proved that microwave treatment assisted with nano-catalysts could increase the cracking capacity of macromolecules and the production of coke.