油砂固-液两相流体作用下金属网布筛管抗冲蚀性能数值模拟

Numerical simulation of erosion resistance of metal mesh screen pipe under the action of oil sand solid-liquid two-phase fluid

油井出砂后,油砂固-液混合物冲蚀完井筛管,造成筛管防砂失效。针对筛管结构复杂,室内防砂筛管冲蚀实验误差大的问题,根据金属网布筛管结构特点,使用Fluent仿真模拟软件平台建立金属网布防砂筛管三维模型,研究防砂筛管在不同冲蚀速度、冲蚀液质量分数下的速度分布、切应力分布和冲蚀速率分布。研究发现:筛管速度、切应力冲蚀速率的最大值均位于保护壳流入通道交错处所对应第一层筛网的位置;第一层筛网的最大速度是入口流速的6~7倍,平均切应力是保护壳切应力的1.2倍,平均冲蚀速率是保护壳冲蚀速率的2~3倍。结果表明,第一层筛网是主要的冲蚀破坏易损点。数值模拟仿真技术充分考虑了冲蚀速度、冲击角度和粒径3个因素对冲蚀腐蚀的影响,可以模拟长时间的防砂筛管冲蚀,准确预测出金属网布防砂筛管每层结构的冲蚀速率,可为井下防砂提供理论指导,同时也可为冲蚀寿命预测提供理论依据。

After the oil well is sanded,the oil sand solid-liquid mixture erodes the completion screen,causing the screen to fail in sand control.Due to the complex structure of the screen,there is a large error in the erosion experiment of the indoor sand control screen.According to the structural characteristics of the metal mesh screen,using the Fluent simulation software platform,a three-dimensional model of the metal mesh sand control screen was established to study the speed distribution,shear stress distribution and erosion rate distribution of the sand control screen under different erosion speeds and mass fraction of erosion fluid.It is found that the maximum values of the screen speed and shear stress erosion rate are located at the position of the first layer of screen where the protective shell inflow channel is interlaced;the maximum speed distribution on the first layer of screen is 6-7 times of the inlet flow rate.The average shear stress is 1.2 times of the protective shell,and the average erosion rate is 2-3 times the erosion rate of the protective shell.The research results show that the first layer of screen is the main erosion damage vulnerable point.Numerical simulation technology fully considers the impact of erosion speed,impact angle and particle size on erosion and corrosion.It can simulate long-term erosion of sand control screens and accurately predict the erosion of each layer of the metal mesh sand control screen.Erosion rate provides theoretical guidance for downhole sand control and at the same time provides theoretical basis for erosion life prediction.