Due to the poor salt tolerance and heat resistance of the partially hydrolyzed acryl amide in the reservoir of high temperature and high inorganic salt

and the poor ability of shear

the hydrophobically associating terpolymersacrylamide-hexadecyl ally ammonium chloride-2-acrylamino-2-metyl propane sulfuric acid (AM-C16 DMAAC-AMPS) is prepared by micelle polymerization with the nonionic monomer-AM

the anionic monomer-AMPS

the cationic monomer-C16 DMAAC

It is investigated that the effect of the content of the hydrophobic monomer

anionic monomer

cationic monomer

reaction temperature and the concentration of the inorganic salt and the surfactant on the viscosity of the hydrophobically associating aqueous soluble terpolymers in brine．The results show that the aqueous soluble hydrophobically associating terpolymers(1000 mg/L) have good viscofication effect in brine(20000 mg/L)

when the content of the hydrophobic monomer is l.2％

and of the anionic monomer is 30％

the hydrophobically associating terpolymers can meet the need of polymer flooding in reservoir of the high concentration inorganic salt．