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Corrosion and Protection of Sulfur-Containing Wastewater in Oil Fields and Refineries 1. Corrosive Damage: The containers and pipelines used for oil extraction and water injection in oil fields, as well as the tanks and pipelines in the wastewater treatment areas of refineries, are all severely corroded by sulfur-containing wastewater. Since the wastewater contains large amounts of H2S, NH3, HCN, and CO2, as well as numerous harmful ions such as Cl- and SO42-, along with a high number of bacteria, and the temperature is as high as 70–80°C, some of it also contains phenolic corrosive substances, failure to implement effective anti-corrosion measures can lead to severe corrosion of these equipment. This can result in thinning of the carbon steel surface, local perforations, bubbling, cracking, and stress corrosion cracking at welds, ultimately leading to the destruction of the equipment. 2. Analysis of corrosion causes: Different crude oils and production processes result in varying corrosive agents in the wastewater; as a result, the causes and mechanisms of corrosion differ to some extent. Generally speaking, however, the following points apply: (1) Corrosive agents such as H2S, NH3, and HCN present in sulfur-containing wastewater cause corrosion due to electrochemical reactions that generate H2S ； ⑵Hydrogen embrittlement corrosion caused by hydrogen atom penetration ； ⑶The wastewater contains large amounts of NH3, CN-, and Cl-. The substances formed as a result of their reaction with H2S, namely NH4HS and (NH4)2S, are highly corrosive ； ⑷Phenolic corrosion agents can damage the coating, exacerbating corrosion. 3. Anti-corrosion coating design: Based on the actual application experience of various anti-corrosion coatings, it has been found that conventional coatings (ordinary epoxy paint, epoxy coal tar pitch coating, epoxy phenolic paint, polyurethane paint, chlorosulfonated coating, highly chlorinated polyethylene coating, acid-resistant panels made of epoxy and furan mortars, unsaturated polyester fiberglass, epoxy ethylene ester fiberglass) fail to meet the required standards; they often develop color changes, delamination, and peeling within less than a year. In contrast, coatings such as epoxy glass flake coating, epoxy furan coating, epoxy fiberglass, epoxy polysulfide rubber coating, vinyl ester coating, and metal nano-polymer alloy coating have shown good performance in practical applications.