排砂管线弯接头的冲蚀机理研究

Study on Erosion Mechanism of Bending Joint in Blooey Line

排砂管线是气体钻井中不可缺少的地面设备之一,在高压高产气井的钻井中存在安全隐患,常规情况下通常被人们忽略。排砂管线失效主要由高速气流中的固体颗粒冲蚀破坏,通常发生在弯接头部分。针对排砂管线弯接头的冲蚀失效情况,开展冲蚀破坏机理的理论研究和数学模型研究,对弯接头的冲蚀攻角、冲蚀函数、冲蚀颗粒形状系数以及固体颗粒的受力状况进行探讨。建立排砂管线弯接头的CFD有限元模型,可以任意改变弯接头的角度,定量地模拟不同工况下含有固相颗粒的多相流对弯接头的冲蚀速率和冲蚀机理,对排砂管线在气体极限流量100×104m3/d和50×104m3/d的工况下,对不同含砂量进行一系列的CFD仿真模拟,得出冲蚀速率随弯接头角度变化定量的关系曲线,为弯接头的结构优化设计提供理论依据。

Blooey line is the one of indispensable ground equipment in gas drilling, which has potential safety hazard in high pressure and high yield gas well drilling, but it is usually ignored in common. Because of solid particle erosion in high speed air flow, failure destruction of blooey line occurs mainly in bending joint. Based on erosion destruction of bending joint, we launch the study of erosion destruction mechanism and mathematical model, and carry on the theory discussion on erosion angle of attack, erosion function, erosion coefficient of particle shape and the stress of the solid particle. At the same time, this paper established the CFD finite element model and the angle of bending joint can change arbitrarily, which quantitatively simulates erosion rate of multiphase flow containing solid particles to blooey line bending joint under different conditions and do erosion mechanism research, and there is a series of CFD simulation study under the limitation flow rate （100×10^4m3/d and 50×10^4m3/d） in different sand content. Finally, obtained quantitative relation curves between erosion rate and the angle of ioint, it orovides the theoretical basis for the blooev line bendin~ Joint structure ootimization in this naner.