富含CO凝析气井的腐蚀与防腐技术

Study of corrosion mechanism and prevention methods for gas well in condensate gas reservoir with rich CO

田红政

Tian Hongzheng

中国石油化工股份有限公司华东分公司, 江苏 泰州 225300

East China Branch of SINOPEC, Taizhou 225300, China

富含CO2凝析气藏气井的腐蚀具有普遍性, 作者对凝析气井多相流动腐蚀现象进行了阐述, 分析了富含CO2凝析气藏气井的腐蚀机理是金属表面在酸性环境中形成微电池产生的电偶腐蚀作用的结果, 研究了凝析气井多相流动腐蚀影响因素, 包括温度、CO2分压、流速、相态的影响、流型等。提出了几种凝析气井腐蚀的防治的有效措施:不锈刚管、玻璃钢管, 涂镀层油管, 加入缓蚀剂, 阴极保护, 增加pH值, 并以黄桥富含CO2凝析气田为例, 指出对该富含CO2凝析气田所采取防腐措施是有效的。

Corrosion in condensate gas well is very common, this paper describes multi-phase flowing corrosion phenomenon. Corrosion mechanism in gas well in condensate gas reservoir with rich CO2 is analyzed, which is electronic dipole corrosion produced by micro cell formed on metal surface in acid environment. Moreover, affecting factors of corrosion for multi-phase flowing in condensate gas well are discussed such as temperature, partial pressure of CO2, flowing rate, phase, flowing type, etc. And effective prevention technologies are presented, for example, stainless steel pipe, glass lined steel pipe, coated tubing, corrosion inhibitor injection, cathodic protection, pH value increasing and so on. Corrosion case of Huangqiao Gasfield rich in CO2 condensate demonstrates the effectiveness of technologies to resist carrion in gas well in condensate gas reservoir with rich CO2.