Evaluating the influence of extraction methodologies on the chemical characteristics of asphaltene

Abstract

Petroleum can be divided into four major fractions known as Saturates, Aromatics, Resins, and Asphaltenes (SARA). Asphaltenes, defined as molecules insoluble in n-alkanes and soluble in aromatic compounds, are the most polar and highest molecular weight components present in petroleum, forming nanoparticles dispersed in the oil. During oil production, variations in composition, temperature, or pressure can cause these particles to precipitate, which, when deposited on pipeline surfaces, may reduce or interrupt flow, resulting in significant economic losses. In low-pressure systems, asphaltene precipitation can be induced by adding n-alkanes, forming micrometric particles separable by sedimentation. The quantity and type of n-alkane used influence the volume and characteristics of the precipitated asphaltenes. This study will investigate how different n-alkanes affect the chemical properties (polarity, molecular weight, aromaticity) and aggregation of asphaltenes in a dead oil from the Brazilian pre-salt region, aiming to deepen the understanding of asphaltene precipitation mechanisms and enable the development of more effective precipitation inhibitors.