Effect of HCO_3^- concentration on CO_2 corrosion in oil and gas fields

作     者：Guoan Zhang Minxu Lu Chengwen Chai Yinshun Wu 

作者机构：Corrosion and Protection Center University of Science and Technology Beijing Beijing 100083 China 

出 版 物：《Journal of University of Science and Technology Beijing》 (北京科技大学学报（英文版）)

年 卷 期：2006年第13卷第1期

页      面：44-49页

核心收录：

学科分类：080503[工学-材料加工工程] 0806[工学-冶金工程] 08[工学] 0818[工学-地质资源与地质工程] 0815[工学-水利工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0802[工学-机械工程] 0813[工学-建筑学] 0814[工学-土木工程] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：financially supported by the National Natural Science Foundation of China Key Program (No.50231020) the National Key Basic Research and Development Plan Program (No. G1999065004) 

主　　题：oil and gas fields carbon dioxide corrosion bicarbonate concentration polarization curves 

摘      要：The effect of HCO3^- concentration on CO2 corrosion was investigated by polarization measurement of potentiodynamic scans and weight-loss method, Under the conditions of high pressure and high temperature, the corrosion rate of steel X65 decreased with the increase of HCO3^- concentration, while pH of solution increased. SEM, EDS, and XRD results of the corrosion scales indir cated that the typical FeCO3 crystallite was found at low HCO3^- concentration but Ca（Fe,Mg）（CO3）2 was found at high HCO3^- con- centration. Ca^2＋ and Mg^2＋ are precipitated preferential to Fe^2＋ at high pH value. Potentiodynamic polarization curves showed that the cathodic current density decreases with the increase of HCO3^- concentration at low HCO3^- concentration. When the HCO3^- concentration reaches 0.126 mol/L, increasing HCO3^- concentration promotes cathodic reactions. Anodic behavior is an active process at low HCO3^- concentration and the anodic current density decreases with the increase of HCO3^- concentration. An evident active-passive behavior is exhibited in anodic process at 0.126 mol/L HCO3^-.