针对合水油田站内水处理系统腐蚀严重的问题，利用离子色谱、化学滴定法、扫描电子显微镜（SEM）、能谱仪（EDS）等测试方法对采出水水质、除油沉降罐内构件表面腐蚀产物形貌与化学成分进行了测试分析。同时提出了相应的防治措施，并开展了现场试验。结果表明：除油沉降罐主要的腐蚀类型为垢下腐蚀和氧腐蚀。由于进站采出水来源不同，配伍性差，又高含Ba²⁺、Ca²⁺、SO₄^2-等成垢离子，在混合后易发生结垢。结垢物在除油沉降罐内沉积后，因分布不均匀，导致积垢区域离子扩散与介质传递受阻，形成闭塞环境。在酸化自催化作用下，积垢区域腐蚀加速，引起局部腐蚀。对此，可采用加注药剂（缓蚀剂、阻垢剂、杀菌剂及除氧剂）的方式改善水质，将均匀腐蚀速率控制在0.15 mm/a以内，从而有效减缓水处理系统设备及管线的腐蚀。

In view of the serious corrosion problem of the water treatment system in Heshui oilfield, the produced water, the morphology and composition of corrosion products on the surface of internal components were tested and analyzed by ion chromatography, chemical titration, dissolved oxygen detection tube, scanning electron microscope (SEM), energy spectrometer (EDS). Meanwhile, corrosion prevention measures were put forward and field tests were carried out. The results show that the main reasons for the corrosion of the oil removal sedimentation tank were under-scaling corrosion and oxygen corrosion. Due to the different sources of produced water entering the station, poor compatibility, and high content of Ba²⁺, Ca²⁺, SO₄^2- and other scale-forming ions, it was easy to scale after mixing. After the fouling material was deposited in the oil removal sedimentation tank, due to uneven distribution, the ion diffusion and medium transfer in the fouling area were blocked, forming a closed environment. Under the action of acidification autocatalysis, corrosion in the fouling area were accelerated, causing localized corrosion. In this regard, the water quality could be improved by adding chemicals (corrosion inhibitors, scale inhibitors, fungicides and deoxidizers) to control the uniform corrosion rate within 0.15 mm/a, so the corrosion of water treatment system equipment and pipelines could be controlled.