Sulfonic-Acid-Based Pseudogemini Surfactant Stabilized Emulsions in Acidic Environments: Removal of Organic-Inorganic Hybrid Blockage

At present, many researchers are paying attention to pseudogemini surfactant system. In our previous study, oleic-acid-based pseudogemini surfactants (D-OA) assembled by electrostatic interaction between polyether amine (Jeffamine D230) and oleic acid (OA) exhibit extremely high surface activity, but are pH-responsive and unstable in acidic environments. In this paper, OA is replaced by dodecylbenzene sulfonic acid (DBSA) to assemble sulfonic-acid-based pseudogemini surfactants (D-SA). D-SA can stabilize oil-in-water (O/W) emulsions in acid solutions with 4 mol/L H+ concentration, whereas the preferred O/W emulsions are inverted to water-inoil (W/O) with further increase H+ concentration in the aqueous phase. The cost-efficient O/W acidic emulsions have excellent salt-resistance, thermal stability, and controlled release of DBSA. Additionally, the acidic emulsions have a dual action that capable of removing asphaltene deposits and dissolving calcite scales (CaCO3), with the maximum corrosion efficiency exceeding 85 %. This study extends the use of pseudogemini surfactant assembled by electrostatic interaction in harsh environments, which is likely to be of significant potential for practical applications to acidification and unblocking of unconventional oil and gas reservoirs.