中低渗油藏C2断块阜一段中高含水期调驱技术研究

Conformance control flooding for mid- low permeability reservoir in C2 block at mid-high water- cut stage

C2断块进入开发后期,储层非均质性强,综合含水高,开发效果变差。针对C2断块的开发现状,开展了调驱技术研究。通过大量室内实验研究,优选出合适的调驱体系。实验结果显示:在134×10-3μm2天然岩心中,1200mg/L调驱剂的封堵率为83.35%,驱油效率为15.46%,表明其具有较强封堵能力和较高驱油效率。结合物模和数模的研究,优化调驱参数并制定油藏调驱方案。段塞结构为:前缘段塞1200mg/L凝胶,主体段塞1200mg/L聚合物,抗稀释段塞1500mg/L聚合物。经预测该调驱方案实施后可累计增油6355.8t,吨聚增油186.9t/t。

At the later stage of development,C2 block has strong reservoir heterogeneity,high water - cut,and poor de-velopment effect. According to the development situation of C2 block,the conformance control flooding was studied. Through a larger number of lab experiments,the suitable conformance control system was selected. The experimental results showed that under the condition of the conformance control system with a concentration of 1,200 mg/ L and natural core with a permeability of 134 × 10 - 3 μm2 ,the plugging rate was 83. 35% and the oil displacement efficiency was 15. 46%OOIP. This indicated strong plugging ability and high oil displacement efficiency. Based on studies of the physical model and mathematical model,injection parameter and displacement scheme were optimized. The optimal displacement scheme was as follows：pre - slug of gel with a concentration of 1,200 mg/ L,main slug of polymer solution with a concentration of 1,200 mg/ L,and anti - dilution slug of polymer solution with a concentration of 1,500 mg/ L. If the displacement plan is implemented,the project will reach an accumulative increased oil of 6,355. 8 tons,with an incremental oil of 186. 9 tons per ton of polymer.