Preparation and evaluation of erucamidopropyl dimethyl amine oxide used as alkali-free oil displacement agent

Surfactant is a kind of chemical that is widely used in the oilfield. It often serves as chemical oil displacement agents in the surfactant–polymer flooding or alkali–surfactant–polymer flooding. The commonly used surfactant is petroleum sulfonate. However, its unstable property often limits its use. In this paper, erucamidopropyl dimethyl amine oxide was prepared and its potential use in surfactant–polymer flooding was investigated. The results showed that the interfacial tension between crude oil and surfactant–polymer solution could be lowered to ultralow at a concentration of 0.05% (m/m) surfactant. The surfactant–polymer system (0.05% of surfactant and 1500 mg/L of polymer) could withstand adsorption twice. The core flood test indicated the above system could give 22.5% of incremental oil recovery over water flood.