An Investigation of Asphaltene Deposition Mechanisms During Natural Depletion Process by a Two Phase Modeling Using Genetic Algorithm Technique

In this work, the natural depletion process in sandstone and carbonate cores was modeled to investigate the asphaltene deposition mechanisms. A new permeability reduction correlation was proposed based on the Minssieux model that considers a combination of surface deposition, pore throat plugging, and filtration cake mechanisms. The results showed that the filtration cake is a dominant asphaltene deposition mechanism during natural depletion process in both core samples. Therefore, a modified model was proposed with adding formation of filtration cake mechanism due to pore filling to the Wang and Civan deposition model. The absolute average deviation (AAD (%)) for permeability reduction between the results of the three models (including new correlation, the modified model, and Wang and Civan model) and the experimental data were calculated and reported. These values for the three models were 3.28, 2.67, and 4.83% for sandstone core and 3.01, 2.58, and 4.69% for carbonate core respectively. The results showed that the modified model proposed in this study presented good performance for asphaltene deposition prediction.