Synthesis And Performance Evaluation Of A New Hydrophobic Associating Polymer

Polyacrylamide (PAM) is a kind of linear water-soluble polymer with the most widely used,which is applied in petroleum, chemical engineering, water treatment and other fields.As an important energy and chemical raw materials, oil is a limited and non-renewable resource. Therefore, we must research and develop the new oil recovery technologies in order to ensure the long-term and stable supply of oil. At present,because of bad tolerance of salt, shear rate and temperature, the application of partially hydrolyzed polyacrylamide which used in China is greatly limited. So the study of hydrophobically associating polyacrylamide was carried out to rasie the salt, shear rate and temperature resistance of oil recovery additive.Two hydrophobic monomers were synthesized. A new hydrophobically associating polymers BSC14-1was synthesized with hydrophobic monomer Fourteen alkyl two methyl-(2-methylacrylamide) ethyl ammonium chloride.The effects of experimental factors such as mass fraction of monomer,initiation temperature, amount of initiator,pH, hydrophobic monomer concentration andadditives on the molecular weight of the polymer were studied and then the optimum synthesis conditions were determinded. The obtained optimum reaction conditionswere as follows:monomer concentration is30%, AM:AMPS:AA:C14MAC the molar ratio of85.8%:5%:9%:0.2%, initiation temperature of15℃, pH value6.5, hydrophobic monomer molar fraction of0.2%, the initiator AC-land K2S2O8concentrations were0.025%and0.003%, additive urea addition was5%. The molecular weights of polymers were measured by the viscosity method, and the structure of the polymers were characterized by the infrared absorption spectrum. It was investigated how the properties of the polymer solution were affected by the polymer concentration, emperature, salinity and shear rate. The critical associating concentration(CAC) apparesd with the increasing of the polymer concentration. Compared with the partially hydrolyzed polyacrylamide, the hydrophobically associating polyacrylamide had better resistance of salinity,shear rate and temperature. And when shear stress disappeared, the apparent viscosity of hydrophobically associating polyacrylamide solution recovered, showing that the shearing action was reversible. It had important significance on inpractical applications.Resistance factor and residual resistance factor of BSC14-1on the different cores were determined,comparing with HPAM. The results show that:by using the same concentration of BSC14-1, The resistance coefficient and residual resistance coefficient on high permeability core is higher than the level core.2000mg/L polymer solution is not suitable for the core which water permeability is less than1.09×10-3μm2. Resistance coefficient and residual resistance coefficient of different polymer on the same level permeation core is measured, the resistance coefficient and residual resistance coefficient of BSC14-1is better than HPAM.Different permeability grade core flooding experiment results show:high permeability for EOR by polymer flooding is higher than the level core, which is higher than the lower permeability core.The same level core, different polymer oil displacement experiment results show:the hydrophobic associated polymer BSC14-1polymer flooding EOR values higher than HPAM EOR values of5.2points.