耐高温交联酸压裂液的研制及其性能评价

针对黏弹性表面活性剂(VES)转向酸使用成本高，耐温性差以及现有胶凝酸破胶不完全的问题，本研究首先通过水溶液聚合法合成稠化剂和有机锆交联剂，然后在质量分数为20%的盐酸水溶液(下同)中将稠化剂通过有机锆交联剂进行交联，得到耐高温交联酸基液，再根据压裂液性能要求添加高温缓蚀剂、助排剂、铁离子稳定剂和黏土稳定剂，研发了一种耐180 ℃高温的交联酸压裂液。采用高温高压流变仪、压裂液摩阻测试仪和表界面张力测定仪等对交联酸压裂液进行性能评价。结果表明，所制备的交联酸压裂液在180 ℃、170 s^-1条件下剪切120 min后，黏度仍可维持为73 mPa·s，加入0.15%过硫酸铵破胶后，黏度降为3.2 mPa·s，高温流变性和破胶性能良好。

Development and evaluation of high temperature resistant cross-linked acid fracturing fluid system

In view of the problems of high cost, poor temperature resistance (less than 160 ℃) and incompletely broken of viscoelastic surfactant system(VES) and existing gelling acid, the thickener and organic zirconium crosslinking agent were synthesized by aqueous solution polymerization at first. In this paper, the thickener was then cross-linked by an organic zirconium crosslinker in a 20% HCl solution, a high temperature resistant crosslinking acid base solution was obtained. Based on this, according to the performance requirements of fracturing fluid, a kind of cross-linked acid fracturing fluid resistant to 180 ℃ was developed by adding high-temperature corrosion inhibitor, drainage aid, iron ion stabilizer and clay stabilizer. The high temperature and high pressure remoter, fracturing fluid friction tester and surface interfacial tension tester were used to evaluate the performance of cross-linked acid fracturing fluid. The results show that the viscosity of the cross-linked acid fracturing fluid can be maintained as 73 mPa·s after shearing at 180 ℃ and 170 s^-1 for 120 min. When 0.15% ammonium persulfate was added to break the glue, the viscosity decreased to 3.2 mPa·s, showing a good temperature resistance and glue breaking performance.