The effect of CaCO3 deposit on corrosion of NaCl - Alkali/ surfactant/ polymer produced water pipeline

In this work, the corrosion behavior of the CaCO3 layer deposited on the NaCl-alkaline/surfactant/polymer flooding pipeline steel is studied. The results showed that in the non-galvanically-coupled state, localized corrosion occurred on the CaCO3 deposit electrode, and uniform corrosion occurred on the bare electrode. The corrosion of the carbon steel was inhibited by the deposited CaCO3 layer, and the galvanic corrosion occurred, which promoted the corrosion of the bare electrode and inhibited the corrosion of the CaCO3 deposit electrode. The polarity of the bare electrode and the CaCO3 deposit electrode was reversed after the 1 h immersion. During the immersion period below 1 h, the CaCO3 deposit electrode was the anode and the bare electrode was the cathode. However, after the immersion for 1 h, the bare electrode became the anode, and the CaCO3 deposit electrode became the cathode.