Gemini型表面活性剂三元复合体系性能和驱油效果

以胱氨酸钠和油酰氯为原料,通过一步反应合成了一种新型阴离子Gemini表面活性剂二油酰胺基胱氨酸钠(Sodium dioleoylamino cystine,SDOLC),利用Texas-500C型界面张力仪和MCR301流变仪研究了Gemini型表面活性剂/HPAM/碱三元复合体系降低油水界面张力性能和黏弹性能,在均质和非均质岩心中评价了体系的驱油效果。结果表明,HPAM的加入不影响Gemini表面活性剂和碱复合溶液与原油界面张力最低值,但可以有效增加体系的黏度。综合考虑界面张力和黏弹性能,选择黏度44mPa·s且与大庆原油界面张力最低值2.4×10-2 mN/m的含质量分数为0.18%HPAM、0.1%SDOLC、0.15%NaOH和0.06%HEDP·Na4体系作为Gemini型表面活性剂三元复合驱油体系。注入0.6PV该体系在均质岩心中水驱基础上可提高采收率26.11%,在非均质岩心中水驱基础上可提高采收率22.25%。

Physicochemical Properties and Oil Displacement Efficiency of Gemini Surfactant ASP Flooding

The anionic Gemini surfactant Sodium dioleoylamino cystine （SDOLC） was synthesized by one-step reaction of sodium cystine and oleoyl chloride .The reducing oil/water interfacial tension properties and viscoelastic properties of Gemini/HPAM/alkali mixed system were investigated by Texas-500C spinning drop interface tensiometer and MCR301 rheometer ,and the oil displacement efficiency in homogeneous and heterogeneous cores were evaluated . It was found that the minimum dynamic interfacial tension magnitude between Daqing crude oil and Gemini surfactant/alkali mixed solution is not affected with the addition of HPAM ,but the viscosities increased .Overall considering the interfacial tension and viscosity ,mixed solution including mass fraction of 0 .18% HPAM ,0 .1% SDOLC ,0 .15% NaOH and 0 .06% HEDP · Na4 was chose as Gemini surfactant ASP flooding system .The viscosity of this system was 44 mPa · s and oil/water interfacial tension was 2 .4 × 10-2 mN/m .Homogeneous and heterogeneous cores were water flooded until 98% water cut ,and then were treated by 0 .6 PV Gemini surfactant ASP slug followed by water flooding to give an enhanced oil recovery of 26 .11% and 22 .25% ,respectively .