高浓度三元复合体系增油效果及其作用机理研究

本文分析了高浓度三元复合驱增油效果的影响因素和经济效益。结果表明，在驱油剂费用相同时，0.12%高分聚合物驱、0.3%非离子表面活性剂/0.25%超高分聚合物二元复合驱、1.2%碱/0.3%磺酸盐/0.25%超高分聚合物三元复合驱的采收率增幅分别为19.6%、15.9%、13.7%。在高浓度三元复合体系黏度相同的条件下，体系界面张力由8.10×10^-1降至5.73×10^-3 mN/m，采收率增幅由23.4%增至27.7%。当三元复合驱黏度由36.8增至134.4 mPa·s时，采收率增幅由18.5%增至32.9%；当段塞尺寸由0.095增至0.475 PV时，采收率增幅由15.6%增至30.7%，但采收率增幅差值逐渐减小。在药剂费用相同的条件下，“聚合物前置段塞+三元主段塞+三元副段塞+聚合物保护段塞”组合的采收率增幅较大（33.8%）。从技术和经济效益方面考虑，推荐三元复合体系聚合物浓度范围为0.2%～0.25%，段塞尺寸为0.380～0.475 PV。对于非均质比较严重的油藏，与驱油剂洗油作用相比，其扩大波及体积作用对采收率的贡献较大。

Enhanced Oil Recovery and Mechanism in ASP Flooding with Higher Polymer Concentration

The influential factors and economic effect of the oil recovery after alkali/surfactant/polymer (ASP) flooding with high polymer concentration were analyzed in this paper. The results showed that under the same displacement agent cost, the recovery efficiency increment of 0.12% high molecular mass polymer flooding, 0.3% nonionic surfactant/0.25% ultra high molecular mass polymer flooding and 1.2% alkali/0.3% sulfonate/0.25% ultra high molecular mass polymer flooding was 19.6%, 15.9% and 13.7% respectively. Under the same viscosity of ASP flooding system, the interfacial tension of the solution decreased from 8.10×10^-1 to 5.73×10^-3 mN/m, and the recovery efficiency increment increased from 23.4% to 27.7%. When the viscosity of ASP system increased from 36.8 to 134.4 mPa·s, the recovery efficiency increment increased from 18.5% to 32.9%. The recovery efficiency increment increased from 15.6% to 30.7% when the plug size increased from 0.095 to 0.475 PV, whose increment difference gradually decreased. In the situation of same chemicals cost, the recovery efficiency increment (33.8%) was higher with the slug combination: polymer solution pre-slug + principal ASP slug + vice ASP slug + polymer solution protect slug. The recommended polymer concentration in ASP system was range from 0.2% to 0.25%, and the recommended slug size was range from 0.380 to 0.475 PV when technical and economic benefits were considered in Daqing Lamadian oilfield. For highly heterogeneous reservoir, the influence of swept volume on oil recovery was more obvious than that of displacement efficiency.