老化对水溶性疏水缔合聚合物流变行为的影响

摘要

AP-P4 solution was prepared by shear thinning of water-soluble hydrophobically associating polymer AP-P4 as an oil displacement agent in Bohai oil field water.The rheological behavior of AP-P4 solution was studied by static and dynamic experiments.The viscosity,viscoelasticity,and activation energy of viscous flow of AP-P4 solution in different aging time were investigated.The results indicate that when shear stress is moderate,AP-P4 solution exhibits shear thickening at low shearing rate and shear thinn at high shear rate in aging time less than 500 h.When shear stress is greater than critical shear stress,both the storage modulus(G') and the loss modulus(G") of AP-P4 solution decrease sharply with the increase of the shear stress in different aging time.When the shear stress remains unchanged,with increasing aging time,the power law index of G' first increases,then decreases,and finally keeps stable,while the power law index of G" keeps increasing.The activation energy of viscous flow of AP-P4 solution decreases with increasing shearing rate in the range of 25-45 ℃.%以水溶性疏水缔合聚合物AP-P4为驱油剂,经渤海油田现场水剪切稀释后得到AP-P4溶液.利用动态和静态流变实验考察了AP-P4溶液的流变行为,研究了老化时间对AP-P4溶液的黏度、黏弹性和黏流活化能的影响.实验结果表明,当剪切应力较小时,老化时间少于500 h的AP-P4溶液在低剪切速率下呈剪切增稠效应,在较高剪切速率下呈剪切稀释效应.当剪切应力大于临界剪切应力时,老化时间不同的AP-P4溶液的储能模量(G')和损耗模量(G”)均随剪切应力的增大而急剧减小.剪切应力不变时,随老化时间的延长,AP-P4溶液的G'的幂指数先增大后减小并趋于稳定,而G”的幂指数则呈增大趋势.AP-P4溶液在25～ 45℃的黏流活化能随剪切速率的增大而减小.