压裂返排液对不携砂滑溜水压裂液性能影响研究

Research on effect of fracturing flow-back fluid on performance of slick water fracturing fluid without carrying sand

为了解决压裂返排液无法重复利用的问题,开展了压裂返排液对不携砂滑溜水压裂液性能影响研究。通过对压裂液表观黏度、助排性能、降阻性能及储层岩心分散率4个方面进行研究,确定了返排液对不携砂滑溜水各项性能指标的影响。实验结果表明,返排液复配比例越高,滑溜水基液表观黏度越小,滑溜水的降阻性能越差。现场应用过程中,返排液复配比例不应高于50%,返排液的加入对压裂液的表面张力有一定的降低作用,可促进压裂破胶液快速返排,降低压裂液对储层的伤害,返排液的岩心水敏程度总体较低,复配后的滑溜水分散率均低于5%。该项技术为提高压裂返排液利用率提供了技术支撑。

In order to solve the problem that fracturing flow-back fluid cannot be reused,the study was carried out on the effect of fracturing flow-back fluid on the performance of slick water fracturing fluid without carrying sand.Through research on the four aspects including apparent viscosity,drainage-assistance performance,resistancereducing performance of fracturing fluid and evaluation of reservoir core dispersion rate,the influence of flow-back fluid on various parameters of slick water without carrying sand was determined.The experimental results showed that the higher the proportion of the flow-back fluid,the lower the apparent viscosity of the slick water base fluid,and the worse the resistance-reducing performance of the slick water.During the field application,the proportion of flow-back fluid should not be higher than 50%.The addition of flow-back fluid has a certain effect on reducing the surface tension of fracturing fluid,which can promote the rapid flow-back of fracturing gel-breaking fluid,and reduce the damage of the fracturing fluid to the reservoir.The water sensitivity of the flow-back fluid on cores was generally low,and the dispersion rate of slick water after mixing was less than 5%.The technology provides the technical support for improving the utilization rate of fracturing flow-back fluid.