基于规范的海底管道阴极保护设计及数值验证

Design and Numerical Verification of Cathodic Protection for Subsea Pipelines Based on Practice

海底管道是海洋油气开采中的重要组成部分,在恶劣的海洋环境中需要对管道外壁进行腐蚀防护。海底管道外壁腐蚀防护方法包括防腐涂层防护和阴极保护。阴极保护包括牺牲阳极法和外加电流法,其中牺牲阳极法主要用于固定式海洋结构物,外加电流法主要用于船舶和半潜式海洋平台。海底管道作为固定式海洋结构物一般采用牺牲阳极法。目前海底管道阴极保护主要采用规范进行设计,因此研究形成了基于规范的海底管道阴极保护设计方法,并采用C#语言开发了相应的设计程序。该设计程序具有可视化界面,便于参数输入,可以提高海底管道阴极保护设计的效率。本研究中,通过采用海底管道阴极保护设计程序,选取某南海油气田海洋环境条件,进行了多个案例计算,得到了满足要求且经济合理的诸如牺牲阳极数量、阳极间距和阳极质量等阴极保护设计参数。

Subsea pipelines are an important part of offshore oil and gas exploitation,and in harsh marine environments,the outer walls of pipelines need to be protected against corrosion.Corrosion protection methods for the outer wall of submarine pipelines include anti-corrosion coating protection and cathodic protection.Cathodic protection includes the sacrificial anode method and the impressed current method.The sacrificial anode method is mainly used for fixed marine structures,and the impressed current method is mainly used for ships and semi-submersible marine platforms.As a fixed marine structure,the submarine pipeline generally adopts the sacrificial anode method.At present,the cathodic protection of submarine pipelines is mainly designed by specifications.Therefore,a norm-based cathodic protectiondesign method for submarine pipelines has been developed,and the corresponding design program has been developed using C#language.The design program has a visual interface for easy parameter input,which can improve the efficiency of cathodic protection design for submarine pipelines.In this study,by using the cathodic protection design program of submarine pipelines,the marine environmental conditions of a South China Sea oil and gas field were selected,and several case calculations were carried out.The cathodic protection design parameters such as the number of sacrificial anodes,anode spacing and anode quality are obtained that meet the requirements and are economically reasonable.