VES自转向酸反应动力学研究

Study on VES Self-diversion Acid Reaction Kinetics

关键词:  转向酸化  VES自转向酸  非牛顿流体  反应动力学  传质速率

Key words:  diversion acidizing  VES self-diversion acid  non-newtonian fluid  reaction kinetics  mass-transfer rate

摘要:

VES自转向酸分流酸化技术是近年来发展的实现大井段、多层系储层改造新方法。酸岩反应动力学参数对预测酸液变粘时间以及变粘位置有着至关重要的影响。本试验在90℃、8MPa的实验条件下,利用旋转圆盘仪来测定VES自转向酸体系酸岩反应动力学的相关参数。研究表明:在不同酸液浓度下反应速率方程中反应级数m=0.7079,反应速率常数k=5.8439×10-6(mol/L)-m.mol/s.cm2。对不同浓度酸液体系的系统传质速率研究表明,在三种不同酸液浓度下系统传质速率分别为:1.0475×10-5mol/cm2.s、8.6567×10-6mol/cm2.s和5.3371×10-6mol/cm2.s,从实验数据看,在高温下VES自转向酸体系反应速率较快,体系pH值上升快,酸液进入储层后迅速建立起粘性堵塞,达到转向分流的目的。

Abstract:

VES self-diversion acid diversion acidizing technique is a newly developed reservoir stimulation approach for long interest interval and multiple zones.The acid-rock reaction kinetics parameter is very important for predicting the viscosifying time and place.This paper studies systematic reaction kinetics using of rotating disk reactor.The results show that at different concentrations obtaining the reaction order m=0.7079,and reaction rate constant k=5.8439×10-6(mol/L)-m·mol/s·cm2,and testing the system mass transport rate at three different acid concentration,the mass transport rate of each concentration is 1.0475×10-5 mol/cm2·s;8.6567×10-6 mol/cm2·s;5.3371×10-6 mol/cm2·s respectively on the experimental condition of 90℃,8MPa.From the perspective of experimental data,VES self-diversion acid’s reaction rate is relative high,which cause a rapid elevation of pH,when acid enter into the reservoir,viscous hinder is built fast,which can meet the aim of diversion.