新型合成聚合物超高温压裂液体系

Research of New Ultra High Temperature Synthetic Polymer Fracturing Fluid

松辽盆地深层火山岩储层埋深大于5 000 m,储层温度高达180℃,需要开发一种能应用于超高温(180℃以上)储层的新型低伤害压裂液。在室内合成交联剂AC-12的基础上,通过优化压裂液添加剂的用量,研发了新型的合成聚合物压裂液配方。室内实验表明,合成聚合物压裂液在180℃下具有很好的耐温耐剪切性能,在180℃、170 s-1剪切120 min后,压裂液黏度在100 mPa.s以上。通过将剪切速率由170 s-1增加到1 000 s-1、2 000 s-1,再降到170 s-1,模拟压裂液在泵入过程中管路高剪切和裂缝低剪切的黏度变化情况,得到该配方高剪切下的黏度恢复能力强,进入裂缝后有足够的黏度使支撑剂全悬浮,该压裂液具有高剪切下的黏度恢复性能。同时,合成聚合物压裂液容易破胶,破胶液黏度低,残渣含量少,可以在高温深井使用。

A new ultra high temperature fracturing fluid was developed which could be used at 180℃.The formula of the fracturing fluid was optimized based on the cross-linker AC-12 and the contents of additives.After shearing for 120 min,the viscosity was over 100 mPa·s with the shear rate 170 s-1 at 180℃,moreover,higher shear rate fracturing fluid in the pipeline and lower shear rate in the fracture were simulated in the shear rates of 170 s-1,1,000 s-1 and 2,000 s-1.The laboratory results showed that the polymer fracturing fluid had higher viscosity recovery rate than normal at high shear rate which could be applied in ultra high temperature deep wells.