Asphaltene, the heaviest and most polar non-hydrocarbon component in crude oil, may interact with waxes and affect the flow and gelation behavior of waxy oils. To further study the effect of asphaltene on the flow and gelation behavior of waxy oils, five wax-containing simulated oils with small dosage asphaltene content were prepared. Through pour point and rheometer test, it is found that asphaltenes can improve the low-temperature rheology of waxy oil. There is no critical turning point above which the low-temperature flowability improved. With an increase in asphaltene content from 0 wt% to 0.1 wt%, notable changes were observed in the properties of the waxy oil. The pour point, which measures the temperature at which the oil becomes too viscous to flow freely, exhibited a decrease from 25 ℃ to 13 ℃. Similarly, the gelation temperature, indicating the temperature at which the oil starts forming a gel-like consistency, also decreased from 29.0 ℃ to 27.1 ℃. These modifications can be attributed to the presence of asphaltene in the oil sample. This outcome can be attributed to the interference caused by the presence of asphaltenes, which disrupts the gel network structure of the waxy oil and consequently hinders its gelation process. Simultaneously, within the low asphaltene content range, an increase in asphaltene content resulted in a considerable decrease in the viscosity of the waxy oil at 10°C, reducing it from 531.5 mPa·s to 14 mPa·s.

Blending with light oil is a commonly used and reliable method of crude oil transportation, and the blending ratio is a crucial operating parameter in determining the safe and efficient operation of the pipeline. In this paper, in-house flow and deposition experiments are used to evaluate the flow and deposition characteristics of crude oils with varying blending ratios. The results show that (1) blending with light oil basically does not affect the shape of the DSC curve of crude oil; (2) blending with light oil will not eliminate the thermal treatment effect, and the mixed oil flowability still remains highly dependent on the thermal treatment temperature; (3) blending with light oil can greatly decrease the abnormal point and oil viscosity, in which the low-temperature viscosity decreases more significantly; and (4) a wax deposition model of mixed oil is obtained through the fitting of Huang’s model, where the blending ratio is a crucial factor in the determination of the model parameters k, m, and n.