普光气田集输系统腐蚀状况分析及防治措施

Analysis of Corrosion Conditons of Gas Gathering System in Puguang Gas Field and Preventive Measures

对普光气田集输系统进行了腐蚀状况统计分析,2010年5月普光气田3号线全部监测挂片的腐蚀速率平均值为0.032 mm/a,总的统计数据趋势是分离器液相出口处腐蚀速率最高达到0.045 mm/a,其次是加热炉进口处为0.040 mm/a,腐蚀速率最低的是分离器气相出口处为0.019mm/a。通过模拟试验对腐蚀因素进行了X-射线衍射分析,结果表明集输系统材质主要受H2S,CO2及单质硫腐蚀,积液矿化度对材质也有一定的腐蚀作用。由缓蚀剂评价试验确定了3号和1号缓蚀剂结合使用的最佳方案。介绍了优化后缓蚀剂的预涂膜、连续加注和批处理的3种加注方式,经优化后集输系统气相和液相的腐蚀速率基本控制在0.030 mm/a以内。

The corrosion conditions of gas gathering system in Puguang Gas Field were analyzed statistically.The average corrosion rates of coupon test in No.3 line of Puguang Gas Field in May 2005 was 0.032 mm / a.the highest corrosion rate was 0.045 mm / a at the liquid outlet of separator which was followed by 0.040 mm / a at inlet of furnace.The lowest corrosion rate was 0.019 mm / m at the gas outlet of separator.The x-ray diffraction（XRD） analysis showed that the gas gathering line mainly suffered from H2S and CO2 and sulfur corrosions.In addition,the minerality of accumulated liquid was also corrosive to the material to some extent.The corrosion inhibitor test confirmed that the combination of No.3 and No.1 corrosion inhibitors was most effective in corrosion control.The pre-filming of corrosion inhibitor,continuous addition and batch addition were described.The corrosion rate of gas-phase and liquid-phase in gas fathering system is controlled within 0.030 mm / s after corrosion inhibitor addition optimization.