Investigation of asphaltene aggregation kinetics in the presence of water-in-oil emulsion

Abstract

Asphaltene is a component of the petroleum liquid defined operationally. It represents the most refractory (or the heaviest fraction). It is well-known that changes in temperature, pressure, or composition can destabilize asphaltenes and cause aggregation and deposition in porous formations, production lines, and processing facilities (Sheu and Mullins 1995). This leads to the study of the behavior of asphaltene aggregation and parameters that could affect the rate of aggregation which, in this case, is water-in-oil emulsion. In addition, the asphaltene aggregation model derived by Haji-Akbari (2013) is applied as a framework in this study which explains the correlation between the time when asphaltene starts aggregating and the important parameters such as viscosity, collision efficiency and initial concentration of asphaltene nanoparticles. The experimental procedure developed by Tabish (2009) is also utilized as a standard procedure for every detection time experiment (the addition of heptane in oil and the aging method) and able to plot the aging time as a function of heptane concentration. As a consequence, the graph shows the rate of asphaltene aggregation comparing between the oil and water in oil. From this graph, it is shown that there are 2 controversial trends regrading 2 different water concentrations in oil. At lower water concentration (1wt% water), the rate of asphaltene aggregation becomes faster but, on the other hand, the rate is slowed down with higher water content (10wt% water). With these results, it can be concluded that water has effect on the rate of asphaltene aggregation.