驱油型可回收清洁压裂液的研制与应用

Development and Application of Recyclable Clean Fracturing Fluid with High Oil Displacement Efficiency

吕乃欣 刘开平 高 燕

Lü Naixin LIU Kaiping GAO Yan

针对在压裂施工中大量使用的胍胶液体系存在回收利用工艺复杂、成本高、效率低等问题，制备了以近肽链结构的黏弹性表面活性剂为主要成分的高效驱油清洁压裂液体系，研究了压裂液的耐温耐剪切性、抗盐、破胶及驱油性能，并在陇东油田进行了现场应用。结果表明，该压裂液耐温 90℃，抗盐可达 100 g/L，在压裂液中加入有机酸调节剂可降低配液水矿化度对压裂液黏度的影响。压裂液的携砂性能良好，破胶彻底，破胶液残渣含量为 2 mg/L，破胶液与煤油的界面张力可达 10-2～ 10-3 mN/m。该压裂液在油田现场成功应用 25井次，单井产量是相临井产量的 6倍。压裂液返排液经分离沉降等简单处理后即可再次配制压裂液，末端返排液处理后用于驱油，可在水驱基础上平均提高采收率 10.67%，大幅降低压裂液对环境的污染。图8表 8参14

In order to solve the problems of hard recycling，high cost，inefficiency of guar gum fracturing fluid，an efficient oil-displacement clean fracturing fluid system with near peptide chain structure viscoelastic surfactant as main component was prepared. The performances of temperature and shear resistance，salt tolerance，gel breaking and oil displacement of this fracturing fluid were studied. Finally，it was applied in Longdong oilfield. The results showed that the fracturing fluid had good temperature resistance（90℃）and salt tolerance（100 g/L）. The addition of organic acid regulator in fracturing fluid could reduce the effect of water salinity on the viscosity of fracturing fluid. The fracturing fluid had good sand carrying property and broke gel thoroughly with 2 mg/L residue content. The interfacial tension between broken fluid and kerosene could reach 10-2—10-3 mN/m. The fracturing fluid had been successfully applied to 25 wells in oilfield，and the output of single well was 6 times than that of adjacent wells. The fracturing fluid could be prepared again after simple treatment such as separation and sedimentation，and used for oil displacement after end-effluent treatment. The oil recovery rate increased by 10.67% on average on the basis of water flooding. The environmental pollution caused by fracturing fluid could be greatly reduced.