聚合物微球水化动态特征及其渗流特性研究

针对渤海油藏调驱技术实际需求，开展了聚合物微球水化动态特征及其渗流特性研究。结果表明，随水化时间延长，聚合物微球吸水膨胀倍数增加，最终膨胀倍数为4.5倍左右。当水化时间低于50 h时，膨胀速度较快，之后膨胀速度减缓，360 h后达到稳定。与聚合物溶液中分子聚集体尺寸分布相比较，2种聚合物微球粒径分布范围都比较集中，其中10^#微球初始粒径中值为4.36 μm，水化240 h后为20.00 μm左右；11^#微球初始粒径中值为8.45 μm，水化360 h后为40.00 μm，膨胀倍数为4.72。在聚合物微球注入岩心过程中，颗粒间黏连和孔隙过滤作用会造成微球在岩心端面滞留和暂堵，进而引起微球注入过程中压力异常升高。在岩石孔隙内，聚合物微球可以进一步水化膨胀，表现出“运移-捕集-再运移-再捕集……”渗流特性。

Research on the Hydration Dynamic Characteristics and Seepage Characteristics of Polymer Microspheres

In order to meet the practical needs of profile control and flooding technology in Bohai reservoir, the hydration dynamic characteristics and seepage characteristics of polymer microspheres were studied in this paper. Results indicate that, with the prolonging of hydration time, the expansion ratio of polymer microspheres increases, and the final expansion ratio is about 4.5. When the hydration time is less than 50 h, the expansion velocity is faster, then the expansion velocity slows down, and finally reaches stable after 360 h. Compared with the size distribution of molecular aggregates in the polymer solution, the size distribution of the two polymer microspheres is relatively concentrated. The initial median particle size of 10^# microspheres is 4.36μm, and then reaches 20.00 μm after hydration for 240 h. The initial median particle size of 11^# microspheres is 8.45 μm, and then reaches 40.0 μm after hydration for 360 h. The expansion ratio is about 4.72. In the injection process of polymer microsphere, the adhesion between particles and the pore filtering effect can cause the retention and temporary plugging of polymer microsphere in the core end, which leads to the abnormal increase of the pressure in the injection process. The polymer microspheres can further hydration expand in the core pore, showing the seepage characteristics of “migration, trapping, re migration and re trapping......”.