Synthesis and properties of novel branched polyether as demulsifiers for polymer flooding

A novel branched polyether is prepared with 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane as a core, amino groups as backbone, and polypropylene oxide (PPO)-polyethylene oxide (PEO) chains as branches based on phenol-amine resin, propylene oxide (PO), and ethylene oxide (EO). The surface activity is investigated by surface tension measurement at different temperature. The increase in PO/EO ratio or PPO chain lengths improve the surface activity and decrease the critical micelle concentration (cmc) as well as increase the temperature. The addition of inorganic salts causes a slight increase in cmc. The demulsification of water-in-crude-oil (W/O) emulsions, whether from polymer flooding or not, shows that the branched polyether is a good demulsifier to break the W/O emulsions. The stability of W/O emulsion in the presence of polyether shows that the highest water dehydration is not necessarily the highest stability index of W/O emulsion due to the turbidity of separated water. The demulsification process is also observed by microscope. Distribution of the polyether after demulsification is evaluated by partition coefficient at various concentrations.