Investigation on Preparation and Enhanced Oil Recovery of pH Responsive Oil Displacement System Based on Chitosan
The chitosan molecule has a large number of hydrophilic sites(amino groups),but contains only a small number of hydrophobic sites(acetyl aminos),and the ability to approach the oil-water interface is further weakened due to steric hindrance caused by the random arrangement of hydrophobic groups.A mixed adsorption layer can be formed between the surfactant and chitosan molecules,which increases the strength of the interfacial film and slows down the aggregation between droplets,thereby synergistically enhancing the stability of the emulsion and improving the temperature and salt resistance of the emulsion.Therefore,the anionic surfactant SDS and the zwitterionic surfactant BS12 were compounded with chitosan in this work.The synergistic pH-responsive emulsion system of chitosan/surfactant was constructed by optimizing and screening the compound ratio by factors such as the stability of the aqueous solution dispersion system and the oil-water interfacial tension.Dynamic light scattering(DLS),static multiple light scattering(S-MLS),interfacial tension and SEM were employed to investigate the pH response behavior of chitosan/surfactant compounds and the resulting emulsions and then verify the synergistic mechanism between chitosan and surfactant.The results showed that chitosan/BS12 displayed good pH response performance as well as enhanced oil recovery capability.The current work provides theoretical guidance for the development and application of stimulus-responsive oil displacement system.
NETL
NSTL
万方数据
