Prediction of Crude Oil Saturate Content from a SimDist Assay

SARA (saturate, aromatic, resins, and asphaltenes) assays are used in the assessment of crude oil stability, in oil characterization for asphaltene precipitation modeling, and in lumped kinetic models for oil upgrading. However, SARA assays are notoriously unreliable with deviations above 5 wt % reported for assays on the same oil performed in different laboratories. In this study, an approach is developed to predict the saturate composition of a crude oil from more reliable and readily available data such as a simulated distillation (SimDist) assay, the asphaltene content of the oil, and the oil density. If the ratio of the aromatic content to the aromatic+resin content for the SARA method of interest is known, the complete SARA composition can be determined. The proposed method is based on more reliable measurements than the SARA assay and therefore offers a means to a more standardized determination of the SARA composition.