An Investigation of the Asphaltene Effect on Wax Precipitation of Iran Asmari Reservoir Dead Crude Oil

Wax and asphaltene precipitations cause many problems and high costs in the petroleum industry; therefore, the significance of studying these depositions’ behavior is considerable. Evaluating the asphaltene effect on wax precipitation can help find the behavioral trends of waxes and prevent them from precipitating. In this paper, Iran Asmari reservoir Dead Crude oil (IADC) and asphaltene from this oil were used for the experiments. The extracted asphaltene was analyzed by FT-IR analysis. The pour point and wax precipitation content were determined according to the ASTM-D97 Standard test and modified UOP 46-64 method, respectively, and Wax Appearance Temperature (WAT) was measured via differential scanning calorimetry (DSC). At low asphaltene concentrations (0 and 0.057 wt %), adding asphaltene decreased the pour point and wax precipitation content. At asphaltene concentrations of 0.057 wt %, the least wax precipitation content and pour point were measured. A rise in pour point and wax precipitation content was observed at more asphaltene concentrations (0.057-20 wt %). The wax appearance temperature of IADC (36.5 °C) has been decreased in asphaltene-free IADC (25.1 °C). By changing the asphaltene concentration from 0 to 0.1 wt %, the behavior of wax precipitation changed intensely, and this behavior varied gently by increasing the asphaltene concentration from 0.1 to 20 wt %.