Calculation of Asphaltene-Resin Precipitation Using AEOS and SRK State Equations as a Physical Compressibility Factor

The amount of resin existing in crude oil highly affects the asphaltene precipitation values and results in formation of precipitation, asphaltene and resin and also pressure and temperature variations in such reservoirs. According to the literature, the effect of resin content has not been studied. The equation of state (AEOS) is one of the most applicable models which was also used in this study. The compressibility factor was assumed to be made of physical and chemical components. SRK equation of state was used in physical component. Considering the fact that asphaltene and resin do not interact in gas phase and that asphaltene and resin precipitations are in liquid state, vapor-liquid and liquid- liquid equilibrium calculations were applied. Asphaltene precipitation values were calculated from simulations the results were then compared to experimental data. Finally the resin precipitation values were measured.