压裂管柱内突扩两相湍流数值模拟

Numerical Simulation of the Sudden Expansion Two-phase Turbulence in Fracture Pipe

采用标准kε-模型,对不同施工排量情况下,压裂管柱内突扩两相湍流进行数值模拟,得到了流线分布、速度分布和砂比分布。模拟结果表明,在压裂管柱内突扩结构处形成了分离流旋涡,并使管壁处砂的浓度增加,流体和局部富集的砂对管壁形成了一定角度的冲刷、磨损作用。随着施工排量的增加,冲刷部位逐渐下移,现场压裂施工后管柱冲刷磨损部位与数值模拟结果基本一致。

Numerical calculations are performed by the standard k-ε turbulence model to simulate the sudden expansion two-phase turbulence in fracture pipe under different flowrates. The fluid pathline, velocity distribution and sand volume fraction are obtained. The numerical simulation results show that the separate flow vortexes take form at the sudden expansion in fracture pipe, the sand volume fraction increase at the wall of pipe, the mixture of fluid and sand impact the wall of pipe at the certain angle. With the flowrate increasing, the impact position moves to downer. It is shown that the numerical simulation results based on the standard k-ε model agree well with the field operation results.