Effect of Thermal Treatment Temperature on Wax Deposition Property of Changqing Crude Oil

The effect of thermal treatment temperature on wax deposition property of Changqing waxy crude oil was detailedly studied through a Couette wax deposition device and DSC analysis. It was found that with the increase of thermal treatment temperature, the wax deposition rate of the crude oil can be inhibited obviously and the aging rate of the wax deposits can be accelerated. The formed wax deposits at the thermal treatment temperatures 50 ℃ and 60 ℃ become two-layer structures, with a thin/hard inner layer and a relatively thick/soft outer layer. When the thermal treatment temperature rises to 70 ℃, the formed wax deposit is too thin to identify the two-layer structure. Then, the influencing mechanism of thermal treatment temperature on wax deposition property of Changqing waxy crude oil was detailedly studied through asphaltenes dispersibility test, DSC analysis and microscopic observation. The results showed that increasing the thermal treatment temperature can greatly improve the dispersibility and activity of the asphaltenes in crude oil, the activated asphaltenes has stronger interactions with waxes and then changes the precipitated wax crystals' morphology, thus greatly improving the crude oil flowablility, which has a significant effect on wax deposition property of Changqing waxy crude oil. © 2019, Editorial Office of Acta Petrolei Sinica(Petroleum Processing Section). All right reserved.