Surface-charge-modified nanocapsules of petroleum sulfonate for reduced retention to carbonate rock surface in high-temperature and high-salinity reservoirs

The technologies of chemical-enhanced oil recovery have been studied for decades, as one of the limitations is the poor colloidal stability and strong mineral adsorption of chemicals in harsh reservoir conditions. This study demonstrates that a Nano-Surfactant (NS) formulation of petroleum sulfonate is optimized through surface charge modification with a cationic cocamidopropyl PG-dimonium chloride phosphate (LPC) surfactant. The NS with addition of LPC shows mitigated negative charge on the micelle surface with maintained temperature and salt tolerance in aqueous phase and 30–50% reduced retention on the limestone core plug. Graphic abstract