Influence Factors of Under-Deposit Corrosion and Corrosion Prevention in Oil Wells

Abstract

In order to ensure the safe production of the oil field，scanning electron microscopy (SEM) and X-ray diffraction (XRD)，combined with wire beam electrodes，were used to observe the corrosion morphology and analyze the corrosion products under the scale in accordance with the actual operating conditions of an oil field in northern Shaanxi.The influence mechanism of Cl-，CO2 and O2 on corrosion under scale was explored by polarization curve and electrochemical impedance spectroscopy，and the corrosion inhibition performance of corrosion inhibitors on corrosion under scale was clarified.Results showed that Cl-，CO2 and O2 could easily penetrate the scale layer and reach the surface of the metal substrate to form corrosion cells，which increased the corrosion tendency.The corrosion inhibitor CH-1 had a small adsorption capacity on the scale sample surface，and had a strong anodic inhibition effect on the corrosion under scale.It could achieve the corrosion inhibition effect through negative catalytic effect，and had good corrosion inhibition performance under scale.

Keywords

• electrochemical corrosion|local corrosion|wire beam electrode|mechanism|corrosion inhibitor