Effect of Temperature Variations on Asphaltene Dynamics in Oil Reservoirs

Abstract

Abstract Asphaltene precipitation, flocculation, and deposition strongly depend on the pressure, temperature, and composition variations (e.g. phase instability due to CO2 injection). The effect of temperature variations on asphaltene precipitation is more complicated compared to the other factors. As temperature increases, oil density decreases while at the same time entropy of the solution increases, resulting in a counter balancing effect. Although some researchers addressed this issue in the literature, there is a lack of comprehensive model that investigates dynamic effect of temperature variations on asphaltene behavior. In this paper, a comprehensive non-isothermal compositional EOS-based reservoir simulator is developed with the capability of modeling asphaltene phase behavior to study the effect of temperature variations on dynamics of asphaltene precipitation, flocculation, and deposition during cold/hot water injection. The results showed that effect of temperature variations might be favorable or detrimental on oil production, depending on fluid composition, direction of wettability alteration, and dynamic changes in reservoir condition. Each of these factors has a distinct effect on the asphaltene behavior, and neglecting such effects may result in a significant error in the prediction of asphaltene behavior, and consequently, oil production rate.