基于CFD的压裂施工中定压节流器结构优化

为了减轻压裂过程中流体对定压节流器和外面套管的损坏,利用流体动力学分析软件FLUENT中的标准k-ε模型,对节流器附近流场和压力分布进行数值模拟分析,进而对套管内封隔器分段压裂工艺中定压节流器的入口形状和出口形状进行优化。计算结果表明,该模型中的节流器空腔内壁存在冲蚀破坏,这主要是由于节流器入口附近有旋流场存在;节流器入口采用流线形过渡形状,可以减弱入口处的旋流场;近似流线形的节流器出口形状能保证在较高的节流器底部压力的条件下,降低工具内壁的动压力,在射流处起到整流作用的同时,降低湍流强度,有利于减弱工具内壁所受冲蚀;组合使用入口过渡形状和流线形出口结构能有效减弱压裂过程中流体对压裂工具的冲蚀破坏。

Structural Optimization of Constant Flow Controller for Fracturing based on CFD

This paper discussed the flow field and pressure distribution of constant flow controller with standard κ-ε equation of computational fluid dynamics （CFD） software FLUENT in order to reduce the damage caused by the erosion of fracturing fluid to flow controller and casings.Based on that,structural optimizations of inlet and outlet of flow controller were made.The results showed that the presence of vortex near the inlet of flow controller caused the inner wall erosion damage.Streamlined transition inlet can weaken the vortex effect,and approximant streamlined shape of flow controller outlet can remain enough pressure at bottom part with lower dynamic at the inner wall,which is helpful to reduce the turbulence intensity and prevent tool from erosion.Combined the inlet transition traits with streamlined outlet structure can effectively weaken fracturing fluid fracturing tool erosion damage.