聚丙烯酰胺压裂液流变行为影响因素研究

A Study on the Influence Factors on the Rheological Behaviors of Polyacrylamide Fracturing Fluid

通过考察聚丙烯酰胺(PAM)压裂液质量分数,温度,pH及金属离子研究了聚丙烯酰胺压裂液的黏度。结果表明,增加PAM质量分数,压裂液黏度上升,非牛顿性增强,质量分数1.0%PAM压裂液黏度可达到施工要求;温度升高,压裂液黏度下降,非牛顿性减弱;改变PAM压裂液的pH环境也可造成黏度下降;金属离子对PAM黏度影响从大到小顺序依次为Mg2+>Ca2+>Na+>K+,符合扩散电层理论。静态悬砂实验表明,聚丙烯酰胺压裂液在质量分数为1.0%及60℃时,悬砂沉降速度达14.88 min/cm,能满足压裂液携砂标准。

The viscosity behaviors of polyacrylamide fracturing fluid were studied through investigating the concentration, temperature, pH and metallic ion. The results show that, along with the increase of the PAM concentration, the viscosity of the fracturing fluid increased, the non-Newtonian behavior was enhanced and the viscosity of fracturing fluid could meet the construction requirements when the mass fraction was 1.0%. The increase of temperature could decrease the viscosity of the fracturing fluid and weaken the non-Newtonian behavior. Changing the pH environment of the PAM fracturing fluid could also result in the decrease of the viscosity. Metal ions could decrease the viscosity of the fracturing fluid, and the effect of metal ions on PAM viscosity was in the order of Mg2＋ 〉 Ca2＋ 〉 Na ＋ 〉 K ＋ , consisting with the diffusion layer theory. The static suspension experiments show that, when the PAM mass fraction was 1% and the temperature was 60 ℃ ,the proppant-carrying time reached 14. 88 min/ cm, which could meet the sand-carrying standard of fracturing fluid.