Solution behavior of water-soluble poly(acrylamide-co-sulfobetaine) with intensive antisalt performance as an enhanced oil-recovery chemical

In the process of oilfield development, salt tolerance is an important property for enhanced oil-recovery (EOR) chemicals. In this study, we synthesized two acrylamide-based sulfobetaine copolymers containing 2-hydroxy-3-[(3-methacrylamidopropyl)dimethylammonio] propane sulfonate (SHPP) or 3-(4-acry-loyl-1-methyl-piperazinio)-2-hydroxypropane sulfonate (SHMP). The interactions between these two copolymers and inorganic salts were compared, and the apparent viscosity (ηapp) behaviors of copolymer - salt solutions at different shear rates and temperatures were investigated. We found that the ηapp of PAPP and PAMP showed intensive antisalt performance, exhibiting an excellent antipolyelectrolyte effect. The happ retention value of 30,000 mg/L PAMP in brine was 86.47 mPa s at 510 s-1, and when the temperature was increased to 90 °C, it was 99.73 mPa s; this was better than that of PAPP under the same conditions. Therefore, PAMP was more applicable as an EOR chemical that have outstanding salt tolerance and temperature resistance.