Garlic juice used as a corrosion inhibitor was added into high temperature acidized solution and oilfield water with or without saturated CO2 or H2 S. The effects of garlic juice on the corrosion behavior of carbon steel were studied using mass-loss method, and the corrosion inhibition mechanism was proposed based on SEM and electrochemical analysis results. The results show that garlic juice can obviously slow down the corrosion of carbon steel in high temperature acidized solution, and the inhibition efficiency reached 95.4% in 15% HCl solution at 80℃. The inhibition efficiency decreased with the increase of the hydrochloric acid concentration. Garlic juice can also slow down the corrosion of steel in three kinds of oilfield water, and the inhibition efficiency was from 42% to 62%. Electrochemical studies reveal that garlic juice can obviously change the anodic polarizability of steel in acidized solutions, and one kind of passivetion film can form on the steel surface.
Chinese Journal of Applied Chemistry
garlic juice, green corrosion inhibitor, oilfield corrosive medium, inhibition mechanism