Synthesis and Interfacial Activity of Alkyl Polyoxypropylene Sulfonate for Chemical Combination Flooding

A serious of alkyl polyoxypropylene sulfonate surfactant was synthesized. The O/W interfacial activity of alkyl polyoxypropylene sulfonate surfactant was investigated. The results showed that the interfacial tension of Indonesia crude oil/formation water could reach ultralow level (10-3mN/m order of the magnitude) under weak alkali (Na2CO3) concentration from 0.4wt% to 1.0wt% with C16PO8S, C16PO10S, C18PO8S and C18PO10S alkyl polyoxypropylene sulfonate respectively. These surfactants showed good interface activity and salt and divalent cation tolerance ability. Combinations of alkyl polyoxypropylene sulfanate homologies with different carbon chain length could significantly improve the interface activity. The IFT of Indonesia oil/formation water could reach ultralow interfacial tension under alkali free conditions. The combination of alkyl polyoxypropylene sulfonate surfactant with petroleum sulfonate could improve the salt tolerance ability of formula.