驱油剂界面特性和流变性对石油采收率的综合影响  

Synergistic Effect of Interfacial and Rheological Properties of Displacing Fluid in Chemical Flooding

作　　者：岳湘安[1] 侯吉瑞[1] 吕鑫[2] 张立娟[1] 

机构地区：[1]中国石油大学 [2]中海石油研究中心

出　　处：《应用化学》2008年第8期904-908,共5页Chinese Journal of Applied Chemistry

基　　金：国家重点基础研究发展计划("九七三"计划)资助项目(2005CB221303)

摘　　要：利用碱/表面活性剂/聚合物(ASP)复合体系,探索了驱油剂界面特性和流变性对提高石油采收率的综合影响。结果表明,驱油剂的粘弹性越强,在油藏孔隙中的微观流场越易于向孔隙盲端及孔喉等滞留区发展,有利于驱替残留在这些区域中的原油。在以ORS为主表面活性剂的ASP复合体系中,随着碱浓度的增加,驱油剂与原油的界面张力可降至1×10-3mN/m,但同时导致复合体系粘弹性的严重损失,剪切速率为1×10s-1的视粘度降低了一个数量级,使其驱油的综合效应变差。实验结果表明,在非均质岩心中,驱油实验的采收率最高值并不是与高碱浓度条件下的超低界面张力相对应,而是出现在界面张力为1×10-2mN/m量级的低碱浓度区。ASP复合体系的驱油能力实质上是其界面特性与流变性的综合效应作用的结果。研究结果表明,实现复合体系界面特性与流变性的最佳匹配,可获得理想的驱油效果。Alkali/surfactant/polymer（ASP） flooding was taken as an example, and the synergistic effect of interracial and rheologic property （SEIRP） of displacing fluid on enhancing oil recovery has been studied experimentally and theoretically. The results show that the higher the visco-elasticity of the displacing fluid, the stronger the flow disturbance towards bypassed area in pores, and the higher the oil recovery efficiency. Visco-elasticity is beneficial for displacing residual oil. In experiments on natural cores, when the equivalent viscosity of the displacing fluid decreased to a certain value （Critical Viscosity） , decreasing the interracial tension of water/oil cannot improve significantly the displacement efficiency, and the idea of SEtRP was presente. In artificial heterogeneous cores, the effect of the interracial and rheologic property of the ASP solution on the oil recovery efficiency was non-monotonic, and exhibited a maximum value. When the equivalent viscosity was lower than the critical viscosity, even the interracial tension of the displacing fluid was reduced greatly, the oil recovery efficiency also decreased with the decrease of the equivalent viscosity. Under the experiment conditions, the critical viscosity was about 20 mPa · s. The oil displacement ability of the chemical displacing fluid depend on the SEIRP. Therefore, under a certain reservoir condition, it is more important to optimize the SEIRP than to make excessive demand for the ultra low interracial tension. The results are helpful for optimizing the composition of displacing fluids.

关 键 词：石油采收率 ASP复合驱 界面张力 流变性 

分 类 号：O621[理学—有机化学]