海上某油田注水井油管腐蚀断裂原因分析

Cause Analysis of Pipe Corrosion and Fracture of Water Injection Well in Offshore Oilfield

通过腐蚀形貌观察、金相组织分析、化学成分分析、力学性能分析等方法,对海上某油田注水井油管腐蚀断裂的原因进行了深入研究。结果表明,管柱表面腐蚀产物为FeCO3、MgF2、SiO2;在酸化作业中,使用的缓释酸造成了油管的腐蚀断裂。建议检查现场封隔器是否密封不严,并优化后期酸化工艺。

By means of corrosion morphology observation,metallographic structure analysis,chemical composition analysis and mechanical properties analysis,the causes of corrosion and fracture of tubing in a water injection well in an offshore oilfield are studied in depth.The results show that the corrosion products on the surface of tubing string are FeCO3,MgF2 and SiO2,and the corrosion cracking of tubing is caused by slow-release acid used in acidizing operation.It is suggested to check whether the packer on site is not tightly sealed and to optimize the acidizing process in the later stage.