多级粒径非均相调驱体系油藏适应性研究

Study on Reservoir Adaptability of Multistage Particle Size Heterogeneous Modulated Flooding System

为进一步改善渤海油田日益复杂的微观非均质性,提高非均相调驱剂对剩余油动用程度,通过粒径测试和物理模拟等实验手段,开展了多级粒径组合的非均相调驱体系封堵能力评价和适应性研究。结果表明:由3 000 mg·L^(-1)初始粒径为500 nm的聚合物微球和500 mg·L^(-1)初始粒径为30μm的预交联颗粒组成的多级粒径非均相调驱体系具有较好的封堵效果,随渗透率由650 mD增大至4 400 mD,多级粒径非均相调驱体系封堵率由56%增加至93.5%。不同渗透率级差的并联驱油实验表明,多级非均相调驱体系在渗透率级差为1∶5时效果最佳,整体采收率增幅为29.7%,低渗层采收率增幅为74.56%。

In order to further improve the increasingly complex microscopic heterogeneity of Bohai oilfield and improve the utilization degree of heterogeneous flooding agent on remaining oil,the plugging ability evaluation and reservoir adaptability study of heterogeneous flooding technology with multistage particle size combination were carried out by means of particle size test and physical simulation.The results showed that the multistage particle size heterogeneous flooding system composed of 3 000 mg·L^(-1) polymer microspheres with an initial particle size of 500 nm and 500 mg·L^(-1) pre-crosslinked particles with an initial particle size of 30 μm had good plugging effect,and the permeability increased from 650 mD to 4 400 mD,the plugging rate of multistage particle size heterogeneous flooding system increased from 56% to 93.5%.The parallel flooding experiment with different permeability levels showed that the multistage heterogeneous flooding system achieved the best effect when the permeability level difference was 1∶5,and the overall recovery rate increased by 29.7%,and the recovery factor of the low permeability layer increased by 74.56%.