迪那2凝析气田在投产3个月后内部集输和处理厂集气装置陆续发生管线刺漏、管线壁厚减薄、阀门和设备腐蚀等问题。通过对现场腐蚀部位打开、测厚、观察和实验室分析, 对生产工况取样和实验室模拟研究, 表明支线来气造成主管线介质流态突变, 在靠近支线一侧存在低速涡流区、且支线无缓蚀剂从而造成缓蚀剂保护膜断层, 当介质流经低速涡流区时腐蚀性组分和水分聚集, 形成酸性腐蚀环境, 加上高温高压下CO2联合Cl-导致的局部腐蚀速率加剧,以及高流速下的冲刷腐蚀是造成迪那2区块内部集输管线腐蚀的主要原因。据此提出腐蚀对策, 并建议对采集气管线材质提高防腐蚀等级, 采用合金钢以解决腐蚀问题。

Some pipelines of the gas gathering and processing in DINA-2 gas condensate field leaked out and burst, some pipe wall thinned, valves and equipment corroded within 3 months after the plant went into operation. such issues seriously affected the safety of gas production, by opening the corrosion site, measuring the thickness, observing the corrosion morphology and making laboratory analysis, sampling of production conditions for laboratory simulation studies, the results showed that the main line extension to the gas caused mutations in the medium flow pattern, the presence of low-speed vortex region near the side branch and branch no corrosion inhibitor in the branch causewd protection film faults, when the medium flowed through the low-speed vortex area, corrosive components and water accumulated, the formation of acidic corrosive environment, coupled with the increase of localized corrosion rate at high temperature and pressure, and joint erosion-corrosion of Cl- and CO2 at high flow rates were the main reasons for gathering pipeline corrosion in Dina 2 blocks. Some corrosion countermeasures were suggested.