非均质油藏封窜及化学驱复合技术研究

Sealing Channeling and Chemical Flooding Composite Technology Research on the Heterogeneous Reservoir

徐宏明 侯吉瑞 赵凤兰 李伟娜 张磊 张建忠 冷光耀

XU Hong-Ming HOU Ji-Rui LI Wei-Na ZHANG Lei ZHANG Jian-Zhong LENG Guang-Yao

利用单层均质模型及并联填砂管模型，评价改性淀粉凝胶体系的调剖性能。该凝胶体系由4% 改性淀粉、4% 丙烯酰胺单体、成胶控制剂按一定比例组成。凝胶体系成胶前的选择注入性良好，成胶后的残余阻力系数为834 率2548，突破压力梯度高于50MPa/m，封堵率大于99%，可有效解决水窜流问题。利用双层非均质岩心模型，考察3 种后续驱替段塞对提高采收率的影响。由0.3% 聚丙烯酰胺、0.3% 烷基苯磺酸钠和0.1 g/LNaOH组成的三元驱、0.3% 聚丙烯酰胺及水驱的采收率增幅分别为20% 、17% 和10% 。“ 改性淀粉凝胶体系+ 三元复合驱”组合调驱中，改性淀粉凝胶可进一步开采高渗层位残余油，三元复合驱在封堵后可有效启动低渗层位，整体提高采收率37%。

The profile control characteristics of modified starch gel system were studied by monolayer homogeneous core model and parallel sand filling tube model. The gel composed of 4% modified starch, 4% acrylamide monomer and gelatinizing control agent in appropriate proportion. The results showed that the injection performance before gelling was good and the residual resistance factor was 834—2548 after gelling, breakthrough pressure gradient was greater than 50 MPa/m as well as the sealing rate was greater than 99%. So water channeling problem could be solved effectively. The influence of three flooding methods on enhanced oil recovery was evaluated based on double-layer inhomogeneous core model. The oil recovery ratio of ternary flooding including 0.3% polyacrylamide, 0.3% sodium alkyl benzene sulfonate and 0.1 g/L NaOH, 0.3% polyacrylamide flooding and water flooding was 20%, 17% and 10%, respectively. Residual oil in high permeability layer would be further produced by modified starch gel system. After gelling, oil in low permeability layer would be produced effectively by ternary flooding system. The recovery ratio increased 37% by combining modified starch gel system and ternary flooding.