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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 devices. This can result in thinning of the carbon steel surface, local perforations, bubbling, cracking, and stress corrosion cracking in the 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, they include the following: (1) Corrosive agents such as H2S, NH3, and HCN present in sulfur-containing wastewater, which 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. Design of anti-corrosion coatings: Based on the actual usage of anti-corrosion coatings in various applications, it has been found that conventional coatings (such as ordinary epoxy paint, epoxy coal tar pitch coating, epoxy phenolic paint, polyurethane paint, chlorosulfonated coatings, high-chlorinated polyethylene coatings, acid-resistant panels made of epoxy and furan mortars, unsaturated polyester fiberglass, and epoxy vinyl 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 coatings, epoxy furan coatings, epoxy fiberglass, epoxy polysulfide rubber coatings, vinyl ester coatings, and metal nanopolymer alloy coatings have shown good performance in practical applications.