油田水中阴离子及温度对P110钢腐蚀电化学行为的协同影响

Synergistic Influence of Anions and Temperature on Corrosion Behavior of P110 Steel in Oilfield Water

为了获得油田水中阴离子及温度对P110钢腐蚀行为影响的协同性,采用动电位极化、电化学阻抗谱及正交试验等方法研究了在不同条件下模拟油田水对P110钢腐蚀电化学行为的影响。结果表明:随HCO_3^-、Cl^-、S^(2-)浓度增大,P110钢在模拟溶液中的腐蚀倾向增大,腐蚀速率先增大后减小;试验条件下,低浓度的各离子均起到了协同促进作用;温度升高,腐蚀速率则先减小后增大,并影响了其腐蚀倾向;随着典型阴离子浓度增大,电荷传递电阻先减小后增大,P110钢的腐蚀活性也呈相同趋势,温度则相反;试验研究范围内,影响最大的因素是HCO_3^-浓度,其次是S^(2-)浓度,影响最小的是Cl^-浓度,且HCO_3^-浓度、S^(2-)浓度、温度之间的相互作用小。

Corrosion electrochemical behaviors of P110 steel in simulated oilfield water with different conditions were studied by potentiodynamic polarization, electrochemical impedance spectroscopy and orthogonal test methods. Results showed that with the increase of concentrations of HCO3 , Cl- and S2- , the corrosion trend of P110 steel in simulated oilfield water increased, while the corrosion rate firstly increased and then declined. Under the experimental conditions, various ions with low concentration played a synergistic role. As the temperature increased, the corrosion rate firstly decreased and then increased, and the corrosion trend was influenced. With the increase of concentration of typical anions, the charge transfer resistance decreased and then increased, and the corrosion activity exhibited the same trend, but the temperature in the op- posite. Furthermore, in the range of experimental test, the most important factor that affected the corrosion resistance was HCO3 concentration, followed by S2- concentration. The effect of Cl- concentration was the minimum, and the interaction between HCO3- concentration, S2- concentra- tion and temperature was negligible.