Study on Modification of the Asphaltene Stability Estimation Model

Current asphaltene deposition prediction model including phase equilibrium model and colloidal model can predict the conditions for asphaltene deposition, but the input data are too much, and it is difficult to determine and acquire some key parameters, which requires lots of work before prediction and calculation. Hence, for simplifying the prediction process and increasing the speed of estimating asphaltene deposition trend in crude oil, it is necessary to study the analysis method of asphaltene stability in oil deeply to evaluate the asphaltene stability with a small amount of characteristic parameters. In this study, current asphaltene stability estimation or evaluation models were analyzed, and some suggestions for modification were proposed by combing with asphaltene solubility theory, and the modified model was developed. Finally, the prediction accuracy of modified and original asphaltene stability estimation models was compared with 72 crude oils stability calculation results. The research results show that the influence of the four components on asphaltene stability are considered in the optimized model and the estimation results of this model are closer to cases reported in the literature than that of the original model.