Novel Alkyl-Amine Surfactants for CO2 Emulsion Assisted Enhanced Oil Recovery

• Published in: Energy & fuels Vol. 32; no. 8; pp. 8220 - 8229
• Main Authors: Cui, Leyu, Dubos, Fabienne, Bourrel, Maurice
• Format: Journal Article
• Language: English
• Published: American Chemical Society 16.08.2018
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.8b01555

Novel CO2-soluble surfactants are designed for generating stable CO2 emulsion/foam at high temperature (110 °C) and high salinity (220 g/L NaCl). The novel surfactants only consist of alkyl chains and amine heads without any fluorine, silicon, or poly alkyl-oxide groups and outperform the surfactants in literature regarding the solubility, thermal stability, and emulsifying ability in harsh conditions. 0.2 wt % of the novel surfactants are soluble in 220 g/L NaCl brine at pH ≤ 8 from 20 to 120 °C and are soluble in CO2 at high temperature (110 °C) and relatively low pressure (91 bar). The surfactants are thermally stable at 110 °C and pH = 4 under anaerobic conditions. Strong CO2 emulsion can be readily generated in bulk and in porous media at 25–110 °C and 150 bar. Unlike the common surfactants in literature, the performance of the novel surfactants can be profoundly enhanced by salinity and temperature. The strategy for designing these novel molecules and tuning the surfactant formulation for emulsion-assisted CO2 enhanced oil recovery (EOR) is discussed as well.