Inhibition Effect Of Inhibitors On The Stress Corrosion Cracking Of Super13Cr Steel In A Acetic Acid-containing Completion Fluid

In this paper, the inhibition effect of some inhibitors on super13Cr stainless steelcorrosion in CO2-saturated CaCl2completion fluid was investigated by polarization curvesand the electrochemical impedance spectroscopy (EIS) techniques. The results indicate thatpropargyl alcohol (PA) and quaternary-N can effectively inhibit the general and pittingcorrosion of super13Cr stainless steel in completion fluid in the presence of0.2%aceticacid at110℃. If adding small amount of propargyl alcohol into quaternary-N, the mixedinhibitor reaches better inhibition effect. PA has good inhibition effect on general corrosionand pitting corrosion of super13Cr steel in CaCl2completion in the presence of0.03%acetic acid at1.0MPa CO2and125℃.Electrochemical noises (EN) were recorded to characterize the inhibition effect ofinhibitors on SCC of super13Cr steel. The results indicate that super13Cr steel issusceptible to SCC without addition of inhibitor in completion fluid in the presence of0.2%acetic acid at110℃. Low concentrations of PA and quaternary-N promote SCC of super13Cr steel. High concentrations of PA and quaternary-N can inhibit SCC of super13Crsteel effectively. The SCC susceptibility decreases with the increasing of the concentrationof KI.The SCC susceptibility of super13Cr steel was investigated by fast and slow scancurves in CO2-saturated CaCl2completion fluid in the presence of0.03%acetic acid at1.0MPa CO2and125℃. The results indicate that the SCC susceptibility of super13Cr steeldecreases after adding PA, KI and (CH2)6N4.The effect of the concentration of some inhibitors on hydrogen permeation wasinvestigated. The results indicate that low concentration of PA and quaternary-N increaseshydrogen permeation of super13Cr steel. However, high concentration of PA andquaternary-N effectively lower the hydrogen permeation. Hydrogen permeation of super13Cr steel changes little after the addition of KI.