剪切作用对功能聚合物微观结构性能的影响研究

梳型聚合物和活性聚合物是目前常用驱油聚合物,其增黏性和黏弹性是评价其驱油能力的重要指标.为考察剪切作用对两种聚合物溶液性能的影响,分别研究了梳型聚合物和活性聚合物溶液经过模拟炮眼剪切前后的宏观和微观性能变化.结果表明,在高速剪切、拉伸应力作用下,梳型聚合物黏度损失率为40.73%,活性聚合物黏度损失率为70.10%;当剪切频率为0.02 Hz时,梳型聚合物界面扩张弹性降低了19.03%,而活性聚合物界面扩张弹性降低了68.03%;相比活性聚合物,梳型聚合物紧密的空间网状结构虽被部分破坏,但仍有疏松的网络结构,且以聚集体的形式紧密地分散在溶液中,通过DLS及AFM测定表明其粒径尺寸稍有变小;可见梳型聚合物抗剪切能力较活性聚合物强.

Effect of shear action on the microcosmic structure and performance of functional polymer used in oil displacement

Comb-shaped polymer and reactive polymer are two kinds of polymers widely used in the tertiary recovery process at present and their viscosity and viscoelasticity are important indexes for evaluating the oil displacement efficiency. To investigate the effect of shear action on the properties of polymer solutions, the macroscopic and microcosmic properties of the comb-shaped polymer and reactive polymer, before and after shearing through the simulated hole cut, were compared. The results showed that at high-speed shearing and tensile stress, the viscosities of the comb-shaped polymer and the reactive polymer are decreased by 40.73% and 70.10%, respectively. With a shear frequency of 0.02 Hz, the interfacial dilatational elasticities of the comb-type polymer and the reactive polymer are reduced by 19.03% and 68.03%, respectively. Compared with the reactive polymer, the comb-shaped polymer still exhibits a loosen network structure and is present as aggregates dispersed in the solution after shearing, though its super-molecular structure is partially destroyed; the particle size of the comb-shaped polymer, as measured by DLS and AFM, is only slightly reduced. These suggest that the comb-shaped polymer has a superior shear performance to the reactive polymer.