Polymer flooding Is one of most cost-effective methods to significantly improve oil recovery for many mature oilfields. However, conventional polymer can not be applied In high temperature and high salinity formation due to their low tolerance to high temperature and high salinity. This paper will introduce the systhesis process and the evaluation results for a new terpolymer which has been successfully synthesized in lab and successfully applied In high temperature and high salinity reservoirs.The terpolymer, named NKP-85, was successfully synthesized from acrylamlde (AM), a small amount of a hydrophobic monomer N-dodecyl acrylamlde (AMC12) and a polar monomer 2-Acrylamldo-2-methyl-propanesulfonlc add (AMPS) via mlcellar polymerization in water. The effect of initiation temperature and functional Initiator (MP) concentration on the new terpolymer molecular weight has been studied. The performance of the synthesized terpolymer was evaluated according to their molecular weight, salt resistance, thermal stability and their ability to Improve oil recovery over water flooding. Results show that the terpolymer has the best performance at an optimized Initiation temperature of 9°C and a concentration of MP of 150 mg/L. The optimized tempolymer has a molecular weight of 22,000,000 and Its 1,500 ppm solution can still keep a viscosity of 18.7 mpa.s In 32,000 formation water salinity and 85°C within one month, which is significantly better than other commercial available products. The shear rate effect on the polymer viscosity will also be reported.The polymer will have a broad application In polymer flooding since it can be used at severe temperature and high salt condition.
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