文东油田特低渗储层酸化增注体系的研究与应用

Research on Acidizing Stimulation System and Its Application at Especially Low Permeability Reservoir in Wendong Oilfield

针对传统酸液体系反应速度快、酸化半径小和酸化有效期短等缺点,结合文东油田实际情况,研制了高温缓速、深部穿透的缓速酸主体酸配方,并优化筛选得到酸化液添加剂配方。岩心流动试验表明,该缓速酸使天然岩心的渗透率由0.26×10^(-3)μm^2提高至0.47×10^(-3)μm^2。与纳米聚硅体系复合制备HS-L/WFS复合降压增注体系,解决注水过程中黏土水化膨胀问题,大幅延长酸化有效期。已成功实施16井次,施工工艺成功率100%,累计增油量1 395.4 t,取得了良好的酸化增注效果。

In consideration of the rapid reaction rate,small acidizing radius and short acidizing validity period of conventional acid fluid system,an acid formulation of retardance and deep penetration with retarded acid as the main component to be used at high temperature was developed by taking the actual conditions in Wendong Oilfield into account,and an acidizing fluid additive formulation was obtained through optimization. The results of core flow test have shown that the permeability through natural core was increased from 0. 26 × 10（-3）μm2to0. 47 × 10（-3）μm2with this retarded acid. HS- L/WFS Composite Pressure Reduction and Injection Increase System was prepared by compounding this retarded acid with a nanometer polysilicon system,which has eliminated the problem of clay hydration swelling during water injection and extended the acidizing validity period substantially. This acidizing stimulation system has been used for 16 well-times with the construction success percent of 100% and accumulated oil production increase of 1 395. 4 t,indicating that good acidizing stimulation effect has been achieved.