西南石油大学学报(自然科学版)

• 油气化学工程 • 上一篇    下一篇

CaCl2 型采出水对原油储罐底板的腐蚀影响分析

刘宇程,张寅龙,廖斯丞,徐俊忠   

  1. 西南石油大学化学化工学院,四川成都610500
  • 出版日期:2014-10-01 发布日期:2014-10-01

Corrosion Perforation of CaCl2 Produced Water to Bottom Plate of
Crude Oil Storage Tank

Liu Yucheng, Zhang Yinlong, Liao Sicheng, Xu Junzhong   

  1. College of Chemistry & Chemical Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China
  • Online:2014-10-01 Published:2014-10-01

摘要:

针对吐哈油田原油储罐底部穿孔泄露影响油田正常生产及安全的问题,开展了腐蚀过程及影响因素分析研
究。在原油储罐内进行现场挂片120 d 后计算失重腐蚀速率,应用扫描电镜(SEM)分析腐蚀挂片表面的微观形貌,对
储罐底部水溶液和储罐钢材进行成分分析,通过电化学方法研究了储罐钢的腐蚀过程,并测试Cl− 和Ca2+ 对钢材的
腐蚀速率影响。结果表明,挂片在罐底水溶液中出现不均匀的坑蚀,挂片失重速率为0.22 mm/a,电化学测试腐蚀速率
为0.15 mm/a,瞬时腐蚀速率有增加趋势,碳钢表面出现二次钝化溶解现象,在罐底介质中Cl− 和Ca2+ 的增加会加速
腐蚀。为原油储罐底板腐蚀泄露的分析及治理奠定了基础。

关键词: 原油储罐, 底板, 腐蚀穿孔, CaCl2, 电化学分析

Abstract:

An analysis of process and influening factors in Tuha oilfield was made,aiming to solve the problems in oil production
and safety issues caused by perforation leakage on tank bottom. After exposing coupons in the storage tank for 120 days,
corrosion rate of weight loss was calculated. Scanning electron microscope(SEM)was employed to observe the microscopic
corrosion morphology of coupons,and the composition of water and steel at the bottom of the storage tank were analyzed.
The corrosion process was researched through electrochemical method and the influence of Ca2+ and Cl− on corrosion rate was
tested. The results show that the irregular pitting corrosion appears on the surface of coupons hung at the bottom of the storage
tank. The corrosion rate of weight loss is 0.22 mm/a and the corrosion rate tested by electrochemical method is 0.15 mm/a. The
instantaneous corrosion rate presents a trend of gradual increase. Repetitive passivation and solubility of surface film occurs
on carbon steel. Ca2+ and Cl− will accelerate corrosion in water solution in oil tank bottom. The research lays a foundation for
analyzing and solving leakage of tank bottom.

Key words: storage tank, bottom plate, corrosion perforation, CaCl2, electrochemical analysis