关键词: 渤海油藏, 聚合物微球, 膨胀倍数, 粒径分布, 渗流特性

Abstract: 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......”.

Key words: Bohai reservoir, Polymer microspheres, Expansion ratio, Size distribution, Seepage characteristics