The Relationship between the Formation Process of Corrosion Scales and the Electrochemical Mechanism of Carbon Steel in High Pressure CO2-Containing Formation Water
The Relationship between the Formation Process of Corrosion Scales and the Electrochemical Mechanism of Carbon Steel in High Pressure CO2-Containing Formation Water
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DOI：
10.1149/2.030209jes
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发表时间：
2012
影响因子：
3.9
通讯作者：
G. Zhang;M. Lu;Y. Qiu;Xingpeng Guo;Zhenyu Chen
中科院分区：
文献类型：
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作者：
G. Zhang;M. Lu;Y. Qiu;Xingpeng Guo;Zhenyu Chen
采用高压釜现场电化学测试方法，研究了碳钢在高压含CO2地层水中的电化学行为。根据热力学模型，计算了各种物种的平衡浓度和各种电极反应的平衡电位，以确定可能的电极反应。电化学测试表明，在初始阶段，阻抗谱呈现三个时间常数，即高频电容性时间常数、中频电感性时间常数和低频电容性时间常数。随着腐蚀的进行，电感性周期收缩，低频电容性周期增大。阻抗谱出现双容性峰。在最后阶段，低频出现代表扩散效应的瓦尔堡阻抗。电化学机理与腐蚀产物膜的形成过程密切相关。
The electrochemical behavior of carbon steel in high pressure CO 2-containing formation water was studied by in situ electrochemical measurements in an autoclave. According to a thermodynamics model, the equilibrium concentrations of various species and the equilibrium potentials of various electrode reactions were calculated to determine the possible electrode reactions. Electrochemical measurements show that in the initial stage, the impedance spectra exhibit three time constants, ie, capacitive semicircle at high frequency, inductive semicircle at intermediate frequency and capacitive semicircle at low frequency. As corrosion proceeds, the inductive semicircle shrinks and the capacitive semicircle at low frequency enlarges. Impedance spectra exhibit double capacitive semicircles later. In the last stage, Warburg impedance representing diffusion effect appears at low frequency. The electrochemical mechanism is closely related to the formation process of corrosion scales.