油气管道CO2腐蚀过程中弹状流的影响

通过分析弹状流近壁面处的动力边界层和扩散边界层及弹状流对管壁CO2腐蚀的影响,发现弹状流动特性对管壁的质量传递、动量交换、管壁处的电化学腐蚀以及腐蚀产物膜的形成和破坏有显著的影响作用。提出弹状流动形态和CO2腐蚀产物膜特性是管壁腐蚀速率和腐蚀形态的重要影响因素,弹单元内的壁面切应力变化特性、正应力变化特性、壁面传质变化特性以及电化学腐蚀特性的非线性耦合作用是油气管道内壁CO2腐蚀的重要影响因素。在此基础上阐述了CO2腐蚀产物膜的微观结构、力学特性以及膜内的传质特性对腐蚀产物膜的形成、破坏以及修复作用。

EFFECT OF SLUG FLOW ON CO2 CORROSION OF PIPELINE IN OIL AND GAS INDUSTRY

Based on the analysis of hydrodynamic boundary layer and diffusion boundary layer,the effects of slug flow on mass transfer of corrosive species to and of corrosion products from the wall,momentum interchange,electrochemical reaction and corrosion product film were obtained.It is suggested that the non-linear coupling of the characteristics such as the normal stress,shear stress,mass transfer coefficient and electrochemical reaction,has important effect on the CO2 corrosion of pipeline.The key roles of microstructure,mechanical properties,mass transfer of the corrosion product film in the process of corrosion product film's formation,damage and repair are also clarified.