交联聚合物剪切特性及渗流规律研究

Research on shear behavior and perculation rules of crosslinked polymer.

研究了交联聚合物剪切和剪切后再交联的特性及其在孔隙介质中的渗流规律。用机械剪切、在孔隙介质中流动剪切和段塞渗流三种实验方法，用ＵＶ－３０００紫外分光光度计分析出口样品，用付里叶变换红外ＦＴ－ＩＲ漫反射技术分析模型中滞留的聚合物分布。结果表明：未交联的交联聚合物体系在地层条件下和经岩心剪切后都能交联增粘，剪切粘度损失可达７５％以上，停止剪切后在６０℃下静置，粘度在当天即开始回升，３～４天升到最大值，尔后逐渐下降；交联聚合物受机械剪切，粘度可降到原值的０．０７％，但停止剪切后２～４天可恢复到８５％，最大约９０％；交联聚合物注入岩心后再水驱，由于水窜流，驱出聚合物量只有３０％左右，滞留的聚合物在岩心各段均有分布，而入口处的滞留量明显高于其它部位。因此，交联聚合物有较好的抗剪切性，现场应用时具有调剖和驱油双重功能。

Behavior of shear and recrosslinking after shear of crosslinked polymer and its perculation rules through porous mediums are studied.Three experimental methods:mechanical shear,flow shear through porous mediums and slug perculation are used.Outlet samples are analyzed with UV 300 ultraviolet spectrometer.Fourier transform ultrared FT IR diffuse reflection technology is used for analysis of distribution of residual polymer in the simulator.Results show that crosslinking increase the viscosity of uncrosslinked polymer system both under formation conditions and after shearing through core.The loss of viscosity after shearing can reach 75% or more.Keeping in a stationary state at 60℃ after shearing,the viscosity begins to reincrease within a day and reachs the maximum in 3￣4 days.And then it goes down.The viscosity of crosslinked polymer may be reduced to 0.07% of original value after mechanical shear.But 85% even up to 90% of vicosity reincreasing may be obtained in 2￣4 days after shearing.Watr displacement of crosslinked polymer in a core may be only about 30% due to water breakthrough.Remaining polymer distributes all over the core and obviously more at the entrance than at other sections.Therefore crosslinked polymers have a good property of shear resistance and functions of profile control and oil displaement in oilfield application.