化工学报 ›› 2014, Vol. 65 ›› Issue (8): 3098-3106.DOI: 10.3969/j.issn.0438-1157.2014.08.034

• 表面与界面工程 • 上一篇    下一篇

电化学氢通量法用于油气管线在线腐蚀监测

刘向录1, 张德平2, 董泽华1, 刘富发 1   

  1. 1 华中科技大学化学与化工学院, 材料化学与服役失效湖北省重点实验室, 湖北 武汉 430074;
    2 中石油吉林油田采油工艺研究院, 吉林 松原 131200
  • 收稿日期:2013-12-10 修回日期:2014-03-12 出版日期:2014-08-05 发布日期:2014-08-05
  • 通讯作者: 董泽华
  • 基金资助:

    华中科技大学2012年自主创新基金项目(2172012SHYJ003)。

Amperometric hydrogen permeation flux method for online corrosion monitoring of oil and gas pipelines

LIU Xianglu1, ZHANG Deping2, DONG Zehua1, LIU Fufa1   

  1. 1 Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China;
    2 Production Technology Research Institute of Jilin Oilfield of PetroChina, Songyuan 131200, Jilin, China
  • Received:2013-12-10 Revised:2014-03-12 Online:2014-08-05 Published:2014-08-05
  • Supported by:

    supported by the Huazhong University of Science and Technology Innovation Fund in 2012(2172012SHYJ003).

摘要: 通过恒电位阳极极化和失重法考察了不同pH、温度和H2S浓度下Q235A钢在弱酸性介质中的氢渗透电流密度与腐蚀速率的变化情况,着重探讨了各影响因素下氢渗透电流与失重腐蚀速率之间的相关性,为氢通量技术用于油气管道非侵入式腐蚀监测提供依据。研究发现:随着pH降低或介质温度升高,Q235A钢的腐蚀速率与氢渗透电流均逐步增大,且二者之间具有良好的线性相关性。随着H2S浓度增加,Q235A钢的腐蚀速率呈现先增大后降低的趋势,但氢渗透电流则先增大而后趋于稳定;当H2S浓度在5~200 mg·L-1范围内,腐蚀速率与氢电流符合二阶多项式函数关系。通过自制的氢通量探针监测实验管道内腐蚀时,发现过厚的管壁降低了氢电流测量灵敏度,但采用恒电位阶跃法得到的氢渗透电量(氢通量)则与失重腐蚀速率之间具有良好相关性,表明渗氢电量法可用于测量油气管道的内腐蚀速率。

关键词: 腐蚀, 电化学, 石油, 氢渗透

Abstract: The effects of pH, temperature and H2S concentration on hydrogen permeation current and corrosion rate of Q235A carbon steel in weakly acidic medium were studied with the potentiostatic anodic polarization and mass loss methods. The relationship between hydrogen permeation current density and corrosion rate was investigated, aiming at using the hydrogen flux method in online non-intrusive corrosion monitoring of oil pipelines. Increasing acidity and temperature could boost hydrogen permeation current and corrosion rate of Q235A steel in the corrosive solutions, with a good linear relationship between them. The corrosion rate of Q235A steel increased initially and then decreased slightly with increasing concentration of H2S. Meanwhile, hydrogen permeation current also increased at first and then stabilized. When the concentration of H2S was 5-200 mg·L-1, there was a quadratic function between corrosion rate and hydrogen permeation current. Based on inner corrosion monitoring of an experimental pipe by a self-made hydrogenermeation flux probe, the thick pipe wall could decrease the sensitivity of hydrogen permeation current. However, by the help of step potentiostatic polarization, hydrogen permeation flux was found to be linearly related to the corrosion rate of Q235A steel measured by mass loss, indicating that the hydrogen permeation flux could be applicable for the non-intrusive inner corrosion monitoring of thick oil pipelines.

Key words: corrosion, electrochemistry, petroleum, hydrogen permeation

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