深层气井压裂管柱突扩结构内流态及磨损规律模拟

Numerical simulation of flow fluid and wearing in the sudden expansion fracturing tubing of deep gas wells

针对深层气井压裂施工排量和加砂量的不断增加,压裂管柱磨损日益严重,基于欧拉-欧拉双流体模型,结合携砂压裂液的冲刷磨损试验,建立半试验的冲刷磨损模型,对深层气井压裂管柱突扩结构的内流态和冲刷磨损规律进行数值模拟,得到速度分布、砂浓度分布、壁面冲击速度和冲击角度等流场特性,以及突扩管柱的冲刷磨损量.结果表明:在压裂管柱突扩结构后出现分离和再附,从而引起砂浓度的变化,对管柱内壁形成一定的冲刷磨损作用,冲刷磨损量较大部位在突扩后台阶变截面处及再附点后5倍管径范围内,模拟得到的主要磨损部位与现场失效部位基本吻合.

With the increasing of flow rate during fracturing in deep gas wells,the wear of fracturing tubing poses immense concern to the industry.Based on the Euler-Euler two-fluid theory,the wear model was established with the wearing experiment,the numerical simulations have been performed to predict the flow field and the wear rate in the sudden expansion fracturing tubing.The velocity distributions,sand concentration profiles and impact angle are obtained,and the wear rate of sudden expansion structure is also r...