关键词: 污水处理系统, 腐蚀特征, 含醇污水, 含硫污水, 缓蚀剂, 铁离子浓度, 电阻探针检测, 壁厚监测

Abstract:

In the course of extracting gas from a field, several corrosive gases(H₂S, CO₂) will be produced, and at the same time, entrained condensate with high mineralization and high chlorine ion concentration will increase the danger of corrosion and leaking of gas field equipment and pipelines. Corrosion inhibitor addition is a typical anti-corrosion measure in oil and gas fields to lower the danger of corrosion and leakage in unit. Corrosion characteristics analysis is done based on the process flow and corrosion status of the gas field sewage treatment system, the types of corrosion in this environment mainly include acidic water corrosion, carbon dioxide corrosion, wet hydrogen sulfide damage, underdeposit corrosion, and microbial corrosion. Performance evaluation tests are conducted on two types of corrosion inhibitors by simulating on-site sewage corrosion environment, the selected organic amine+quaternary ammonium salt complex corrosion inhibitor has relatively good protective effect in the environment. The on-site verification test results indicate that when the dose is 150 mg/L, the corrosion inhibition rate reaches 85.5%, the corrosion rate of sewage tank in treatment station is controlled below 0.1 mm per year, the leakage rate of the pipeline in the unit area decreases by 62.5%, and the corrosion inhibitor has a good protective effect.

Key words: sewage treatment system, corrosion characterization, alcohol containing sewage, sulfur containing sewage, corrosion inhibitor, iron ion concentration, resistance probe detection, wall thickness monitoring