Effect of Component and Temperature of the Oil-well Produced Water on Corrosion Behavior of Q235 Steel

The effect of component and temperature of the oil-well produced water on the corrosion behavior of Q235 steel was studied using weight loss test method.Corrosion mechanisms of Q235 steel in the produced water were studied by electrochemical measurements such as polarization curves and hysteresis loop combined with SEM and XRD.The results shows that Cl- and SO2-4 had greater effect on the corrosion rate of Q235 steel than HCO-3 and Ca2+.Corrosion rate of the Q235 steel were accelerated always with the increase of the Cl- and SO2-4 concentration.However,it increased first and then reduced with the increase of HCO-3 concentration.When Ca2+ concentration was samll,it had less effect on the corrosion rate,but when the Ca2+ concentration achieved 240 mg·L-1,the corrosion rate decreased quickly.Corrosion rate increased with the increase of temperature when the temperature was below 80 ℃.Corrosion mechanisms of the Q235 steel in the produced water was under-deposit corrosion.