不同结构驱油聚合物的界面剪切流变性质

Interfacial Shear Rheological Properties of Enhanced Oil Recovery Polymers with Different Structures

利用双锥法研究了油田现场用超高分子量部分水解聚丙烯酰胺(PHPAM)和疏水改性聚丙烯酰胺(HMPAM)溶液与航空煤油间的界面剪切流变性质,考察了时间、应变幅度和剪切频率对不同浓度PHPAM和HMPAM溶液界面剪切流变参数的影响.结果表明,只有在适宜的剪切频率条件下,流变数据才能反映界面膜的结构信息.HMPAM分子具有界面活性,能吸附在界面上,其界面膜的强度随时间变化逐渐增强,且在高浓度时以黏性为主;PHPAM分子不具有界面活性,其剪切流变参数没有时间依赖性,界面层以弹性为主.HMPAM能通过疏水作用形成界面网络结构,界面膜的剪切复合模量明显高于PHPAM界面层.HMPAM界面层中网络结构在剪切形变作用下的破坏与重组这一慢弛豫过程是其强度较高的原因.

The interfacial shear rheological properties of ultra-high molecular weight partialhydrolysis polyac-rylamide（ PHPAM） and hydrophobically modified polyacrylamide（ HMPAM） for enhanced oil recovery（ EOR） were studied by biconical method at kerosene-water interfaces. The effects of time, strain amplitude and shear frequency on interfacial shear rheological data of different concentration PHPAM and HMPAM solutions were investigated . The experimental results show that the information for structure of interfacial film can be detected only under optimum shear frequency range. HMPAM molecules have interfacial activity and can adsorb onto the interface, which result in the enhancement of strength of interfacial film with aging time and the viscous nature at higher concentration. PHPAM shows no interfacial activity, which leads to time independence of shear rheological data and the elastic property of film. The interfacial shear complex moduli of HMPPAM are obviously higher than those of PHPAM because the interfacial net structure can be formed by HMPAM mole-cules through hydrophobic interaction. The experimental results of relaxation method show that the slow relaxa-tion process related to destroy and restructure of interfacial net structure under shear deformation is responsible for the higher strength of HMPAM film.