Alkyl polyglycoside: a green and efficient surfactant for enhancing heavy oil recovery at high-temperature and high-salinity condition

Alkyl polyglycoside (APG) is a green surfactant with excellent interfacial activity, emulsified ability, foaming performance and wettability, which has great potential in enhancing heavy oil recovery at high-temperature and high-salinity condition. In this paper, surface tension, interfacial tension, emulsifying ability, emulsion stability and emulsified oil droplet size were investigated for APG. Besides, the effect of temperature and salinity on interfacial activity and emulsification properties of APG was also studied. The results showed that APG had excellent interfacial activity and emulsification property among all these surfactants. Besides, the interfacial activity and emulsification properties of APG almost did not decrease, and even got better along with the increasing temperature or salinity, while those of other surfactants became worse in different degree. The incremental oil recovery by using APG at 90 °C and the salinity of 30 g/L can reach to 10.1% which is nearly two times higher than that of common EOR surfactants. These results indicated that APG is an efficient surfactant for enhancing heavy oil recovery at high-temperature and high-salinity condition.