Asphaltene Precipitation Models: A Review

Asphaltenes are the heaviest and the most polar fractions of crude oil and are defined as a solubility class (typically soluble in toluene but insoluble in n-alkanes like n-heptane). Precipitation and deposition of asphaltenes during production, processing, and transportation of oil are major challenges faced by the oil industry. Over the last 30 years, a number of different models have been proposed for predicting the onset of asphaltene precipitation and also the amount of precipitated asphaltenes. This article reviews the different models that have been proposed for predicting asphaltene precipitation either at atmospheric pressure or under depressurization. A brief summary of the different modeling approaches is presented followed by the description of work done by different research groups. Our focus will be on the description of the basic assumptions underlying different models and also the ability/performance of the model to match the experimental data. Finally, a comparison of models is presented and discussed along with suggestions for improvement.