Development and Evaluation of Asphaltene Inhibitors for Offshore Brazilian Crudes

Abstract

Abstract Asphaltene deposition has been an extremely critical flow assurance challenge in the Oilfield industry and the chemical treatment with continuous asphaltene inhibitors injection has been one of the best solutions for operators to face this challenge preventively, especially in the offshore market where it has the presence of extreme application conditions. This study focuses on optimizing the selection of the best chemicals and dosages of asphaltene inhibitors in Brazilian offshore crudes quickly and effectively. Combinations of different techniques and surfactants (non-ionic and polymeric surfactants) were evaluated in this study. To determine the best solution to be used for these systems, studies were carried out through the colloidal characterization both of asphaltenes in petroleum and of the effect of additives on the asphaltene deposition mechanism using LUMiSizer (Dispersion Analyzer), an equipment that enables extremely effective techniques, with high sensitivity and fast response time, applied for different Brazillian Offshore crude oils To determine the kinetics of destabilization and a tendency of asphaltene aggregate formation, data were acquired from LUMISizer, confirming the minimization of aggregate growth in more stable systems. Results also indicate the existence of a minimum effective concentration, suggesting a minimum dosage that promotes coating in the flakes formed, so that the steric barrier is effective in the curvature of the growth and deposition of asphaltenes. The LUMiSizer was used to rank the efficiency of different inhibitors and dispersants for a specific oil. Such results are even more informative than just saying whether an inhibitor is suitable or not.