压裂液返排期间放喷油嘴设计与工作寿命预测

Design and life prediction of nozzle during fracturing fluid return

压裂液返排期间支撑剂回流返吐导致放喷油嘴磨损严重,依靠经验选择更换油嘴时机,增加了更换油嘴的成本和劳动强度,影响压裂施工效果。基于光滑粒子流体动力学和有限元的耦合方法,结合磨损实验,优化了油嘴的内流道结构和关键参数,优选了油嘴材料,并利用基因表达式编程算法挖掘油嘴磨损的实验数据,建立了工作寿命的预测模型,编制了预测软件。现场应用表明,优化的放喷油嘴耐磨性强,工作寿命提高了75%以上;预测软件计算结果平均误差6.03%,对压裂液高效返排施工具有理论和实际意义。

During the return flow of the fracturing fluid,the backflow of the proppant leads to serious wear of the nozzle.The frequency of replacing the nozzle is determined by experience,which increases the cost and labor intensity of the replacement nozzle and affects the fracturing effect.Based on the coupling method of smooth particle fluid dynamics and finite element method,combined with the wear experiment,the internal flow channel structure and key parameters of the nozzle are optimized,the nozzle material is optimized,and the experimental data of nozzle wear is explored by gene expression programming algorithm.Predictive model of working life is established and the forecasting software is developed.The application effect shows that the optimized nozzle has strong wear resistance and the working life has increased by more than 75%.The average error of the software calculation results is 6.03%,which has theoretical and practical significance for the efficient return flow of fracturing fluid.