On the basis of researching acidizing mechanism, performance evaluation experiments on self-diverting acid system have been done in terms of diverting performance, temperature resistance and break character, etc.It's found that the residual acid has good diverting performance, whose viscosity of can reach 1 128.2 mPa·s at 80 ℃, and drops to nearly 2 mPa·s with 5 wt% ethylene glycol.Conventional acid and self-diverting acid's flow and reaction with carbonate in formation have been simulated by core flooding experiments, showing in salt water drive-acid drive-salt water drive curve.It is shown that in cores of relatively high permeability self-diverting acid has the prior acidizing effect, but for cores of relatively low permeability, the effect is not obvious.For cores with different permeability ratio, self-diverting acid does better than regular acid in treating the low permeable cores.However, when the permeability ratio is too high, the effect of this self-diverting acid system goes worse.%在自转向酸酸化机理研究的基础上,对实验所用酸液体系从增黏性能、破胶性能和转向性能等方面进行了评价.实验发现,残酸在80 ℃时黏度可达到1 128.2 mPa·s,具有良好的封堵增黏性能;5%的乙二醇可使残酸黏度降至2 mPa·s,破胶效果好.通过岩心流动实验分别对常规酸和自转向酸在地层中的反应流动进行模拟,绘制了水驱-酸化-水驱全压降曲线.单岩心流动实验表明,自转向酸对于较高渗透率岩心的处理效果优于常规酸液,而对于较低渗岩心改造效果不明显.双岩心流动实验发现,对于不同渗透率差异倍数的两块岩心,自转向酸对于其中的低渗岩心改造效果要好于常规酸,然而随着渗透率极差进一步增大,自转向酸增黏改造效果变差.
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