Amphiphilically modified chitosan copolymer for enhanced oil recovery in harsh reservoir condition

The intermolecular association of hydrophobic groups to form hydrophobic domains and hydrogen bonding of d-glucosamine units of polymer chains interacts with each other, to cooperatively construct the rigid trunk network for amphiphilically modified chitosan copolymer solution. A novel amphiphilically grafting natural chitosan copolymer (PAMCS) was prepared by using one step water-free radical polymerization strategy and the basic parameters for PAMCS were systematically characterized. The rigid d-glucosamine unit, intermolecular association and hydrogen bonding synergistically endowed PAMCS solution with rheological properties, super-high salt resistance and temperature tolerance in harsh reservoir condition. PAMCS solution exhibited viscoelastic behavior and formulated the unique displacement mechanism in comparison to that for partially hydrolyzed polyacrylamide. Moreover, the mass concentration, injective rate and polymer solution slug related to oil recovery efficiency for PAMCS were investigated from the economic point.