摘要
采用双层非均质岩心模型，将调剖和驱油结合，评价不同级差条件下8种开发方案提高采收率的效果。结果表明，岩心渗透率为30×10-3/1000×10-3μm2时，单独聚合物驱和三元驱使含水率下降约15%，采收率分别提高6.7%和8.3%。用改性淀粉凝胶封堵后，三元驱岩心含水率下降至44%，明显低于聚合物驱和水驱的最低含水率60%、70%，三元驱、聚合物驱及水驱采收率增幅分别为23.5%、19.2%和10.1%。三元驱能有效启动低渗层位，三元复合驱对低渗层位剩余油的开采效果明显好于聚合物驱。“改性淀粉凝胶体系+三元复合驱”组合调驱采收率增幅为40.4%，好于二者单独作用时的采收率增幅加和35.6%，并比“铬凝胶+三元复合驱”组合调驱采收率增幅高4.3个百分点。岩心渗透率为30×10-3/2000×10-3 μm2和30×10-3/500×10-3μm2时，“改性淀粉凝胶体系+三元复合驱”组合调驱采收率增幅分别为45.3%和34.4%，三元驱提高采收率25.1%和22.2%，油藏非均质性越严重，该组合调驱体系开采效果越好。
Abstract
Using double-layer heterogeneous core model, fully playing advantages of profile control and oil displacement, the improving oil recovery effect of eight projects in different permeability contrast conditions was evaluated. The results showed that the water ratio decreased about 15% and oil recovery increased 6.7% and 8.3% in ASP flooding and polymer flooding respectively, when the permeability of core was 30×10-3/1000×10-3μm2. After modified-starch gel was formed, the water cut of ASP flooding declined to 44%, which was significantly less than the lowest value of polymer flooding (60%) and water flooding (70%), and the oil recovery increase was 23.5%, 19.2% and 10.1% in ASP flooding, polymer flooding and water flooding respectively. ASP flooding could effectively start the lower permeability layer and produce better exploitation results than polymer flooding. The oil recovery increase of “modified-starch gel+ASP flooding” was 40.4%, which was better than the oil recovery sum of separately using modified- starch gel and ASP flooding (35.6%), and 4.3 percent higher than that of “chromium gel+ASP flooding”. When the permeability was 30×10-3/2000×10-3 μm2 and 30×10-3/500×10-3μm2, the oil recovery increase of “modified-starch gel+ASP flooding” was 45.3% and 34.4%, and the oil recovery of ASP flooding increased 25.1% and 22.2%, respectively, which indicated that the more severe reservoir heterogeneity, the better exploitation results of combination flooding was.
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