适合海上B油田聚驱后非均相在线调驱性能评价

针对渤海B油田聚合物驱后储层非均质性增强,注水突进严重,产油量低等问题,通过室内实验评价研究,优选了两种非均相在线调驱体系FJX-1和FJX-2,开展了海上油田聚驱后,高含水期阶段非均相在线调剖、调驱性能评价及驱油效率分析。结果表明,聚合物与FJX-1、FJX-2在线调驱体系的封堵效率分别为61.42%、83.45%、93.17%,FJX-2调驱体系的复合黏度、弹性模量均好于聚合物和FJX-1调驱体系,表明其封堵性能与粘弹性能最好,对比液流转向能力,注入聚合物与FJX-1、FJX-2在线调驱体系后,高、低渗透率层的产液分数比分别从87:23、89:21、88:12下降到最低的61:39、48:52和35:65,在后续水驱中FJX-2在线调驱体系的岩心的高、低渗透率层的产液分数比依然可以达到66:34,FJX-2在线调驱体系对高渗透率层封堵效果明显。驱油实验可以看出,三种体系驱过程中最低含水率分别为：54.58、52.97、44.39。聚合物驱后继续FJX-1、FJX-2体系驱,可以提高采收率值分别为6.32%和11.84%,对比可知,最佳的调剖与调驱段塞组合为调剖(1500mg/L PL+1500mg/L JLJ)+调驱(1500mg/L RY+300mg/L PPG),非均相复合体系的调剖与调驱性能,通过对高渗透率层的有效封堵,不仅使中、低渗透率储层中的原油得到动用,同时对残留在储层内的部分原油也发挥了驱替效果。同时,矿场试验也表明,非均相复合驱在海上油田具有广阔的发展前景。

Performance evaluation of heterogeneous on-line control and flooding for offshore B oilfield after polymer flooding

Aiming at the problems of enhanced reservoir homogeneity, severe injection water breakthrough and low oil production after polymer flooding in Bohai B oilfield, through laboratory research and evaluation, three heterogeneous composite systems: FJX-1, FJX-2 and FJX-3, were optimized, and the profile control and profile control performance evaluation, and displacement efficiency analysis of heterogeneous combination flooding in high water cut stage after polymer flooding in offshore oilfield have been carried out. The results show that the plugging efficiency of the three heterogeneous composite systems FJX-1, FJX-2 and FJX-3 are 85.21%, 83.45% and 93.17% respectively, and the plugging performance and viscoelastic performance are better than those of the polymer system. Comparing and analyzing the liquid flow diversion ability of FJX-3 and polymer, after injecting FJX-3, the liquid production fraction ratio of high and low permeability layer decreased from 88:12 to 35:65 after water flooding,indicating that the heterogeneous composite system has obvious plugging effect on high permeability layer.The oil displacement experiment shows that compared with polymer flooding, the enhanced oil recovery values of the three heterogeneous composite systems are 6.32%, 3.59% and 11.84%, respectively. The best combination of profile control and flooding slug is profile control (1500mg/L PL + 1500mg/L JLJ) + profile control and flooding (1500mg/L GN + 300mg/L PPG). The heterogeneous composite system has better profile control and profile control performance. By effective blocking of high permeability layer, the crude oil in the medium and low permeability reservoirs is used, also some crude oil remaining in the reservoir has been displaced. Meanwhile, field tests also show that heterogeneous composite flooding has broad prospects for development in offshore oilfields.