DF-07低温压裂液复合破胶体系的研究及应用

Study and Application of Fracturing Fluid DF-07 Complex Gel Breaker System at Low Temperature

针对低温地层压裂改造液体破胶难度大、储层伤害率高等问题,分析了不同类型破胶剂的破胶机理,研究了由过硫酸盐和引发剂组成的DF-07低温压裂液复合破胶体系的组分比例,评价了不同使用条件下对压裂液携砂粘度和破胶性能的影响程度以及降低残渣含量与保护地层能力,并在永利地区低温储层现场进行了2井次压裂施工应用。通过选择适宜的组分配比与用量,可使压裂液在保持较高的携砂粘度的前提下,达到彻底破胶、降低地层伤害和提高压裂排液及增产效果的目的。

The gel breaking mechanism of different types of gel breakers is analyzed aiming at the problems such as the big difficulty for gel breaking of fracturing modified liquid at low formation and the high ratio of reservoir damage. The composition ratio of the complex gel breaking system of DF - 07 low fracturing fluids consisting of persulfate and the initiator is studied. The effect of the different application conditions on sand carrying viscosity and gel breaking property as well as lowing residue content and formation prevention ability are evaluated. The fracturing application has been conducted twice on - site of low temperature formation in Yongli region. Through selecting proper composition ratio and amount, the fracturing fluid can make the gel break completely under relatively high sand carrying viscosity, in order to decrease the formation damage and increase the fracturing flow back and effect.