A Water-soluble polymeric surfactant with thickening water and emulsifying oil simultaneously for heavy oil recovery

For enhanced heavy oil recovery, either a conventional polymer for thickening water or a surfactant for emulsifying heavy oil has its limitation when each of two is used alone. The former can not effectively drive oil out while the latter could be inefficient in the low swept area. So, a Polymer surfactant with both good viscoelasticity and emulsification of heavy oil is of great significance. Here, by means of polyvinyl alcohol (PVA) grafting with acrylamide (AM) and 2-acrylamide-2-methyl propanesulfonic acid (AMPS), a novel polymeric surfactant PVA-g-P(AM-co-AMPS) was synthesized and the viscosity of PVA-g-P(AM-co-AMPS) aqueous solution can be as much as 27 times more than that of unmodified PVA. The degree of viscosity reduction for the four typical heavy oils can reach to above 85%. The “quasi crosslinking” structure formed by hydrophobic combination with the original hydrophilic groups may be the reason for such a result. The findings of this study can help for better understanding to a construct two-phase viscosity regulator. This polymeric surfactant could be applied in enhanced heavy oil recovery.