油气管道化学腐蚀机理分析及其防护措施

Analysis of Chemical Corrosion Mechanism of Oil and Gas Pipelines and Its Protective Measures

通过采用电化学阻抗谱、盐雾实验以及温度循环等分析方法,评价了环氧树脂、聚氨酯、锌基涂层以及新型复合材料涂层在模拟的盐水、酸性及碱性环境中的腐蚀行为。结果表明:在酸性环境中,管道材料的腐蚀速率最高,达到0.60 mm∙a^(-1),而碱性环境下最低,仅为0.20 mm∙a^(-1)。此外,阻抗分析揭示,酸性环境中的阻抗值从初始的1510Ω·cm^(-2)降至312Ω·cm^(-2),反映出腐蚀介质对防护层的破坏特别迅速和严重。新型复合材料涂层及阴极保护系统能显著提高腐蚀防护效能。阴极保护系统将腐蚀速率降至0.06 mm∙a^(-1),显示出较牺牲阳极保护(腐蚀速率为0.14 mm∙a^(-1))更为优异的防护效果。现场数据显示,采用新防腐技术的管道在实际应用中腐蚀速率显著降低。经过4年的运行后,使用新技术的设施腐蚀速率仅增加至0.6 mm∙a^(-1),而传统防腐措施的设施腐蚀速率增至2.0 mm∙a^(-1)。

The corrosion behavior of epoxy resin,polyurethane,zinc-based coatings,and new composite coatings in simulated salt water,acidic and alkaline environments was evaluated by using analytical methods such as electrochemical impedance spectroscopy,salt spray experiments,and temperature cycles.Experimental results showed that in acidic environments,the corrosion rate of pipeline materials was the highest,reaching 0.60 mm·a^(-1),while in alkaline environments,the corrosion rate was the lowest,only 0.20 mm·a^(-1).In addition,impedance analysis revealed that the impedance value in the acidic environment dropped from the initial 1510Ω·cm^(-2)to 312Ω·cm^(-2),reflecting that the corrosive medium damaged the protective layer very quickly and severely.New composite coatings and cathodic protection systems could significantly improve corrosion protection effectiveness.The cathodic protection system reduced the corrosion rate to 0.06 mm·a^(-1),showing better protective effect than sacrificial anode protection(corrosion rate of 0.14 mm·a^(-1)).Field data showed that pipelines using new anti-corrosion technology significantly reduced corrosion rates in actual applications.After 4 years of operation,the corrosion rate of facilities using the new technology only increased to 0.6 mm·a^(-1),while the corrosion rate of facilities with traditional anti-corrosion measures increased to 2.0 mm·a^(-1).