The down-hole device was corroded seriously after application of nitrogen injection technology in Tahe oil field.In order to determine the corrosion reasons,the down-hole corrosion products were analyzed by scanning electron microscopy (SEM),X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS).The results show that the main elements of corrosion product were Fe and O,and the main composition was Fe3O4.Oxygen carried in nitrogen injection process was the main corrosion reason of the device.According to the corrosion mechanism of oxygen some countermeasures to control oxygen corrosion were proposed,such as changing the nitrogen production method to control the content oxygen,choosing proper materials,and corrosion protection of coating,inhibitor and anodic protection.%塔河油田采用注氮工艺后井下设备发生了严重腐蚀.为确定造成腐蚀的主要原因,采用扫描电镜、X射线衍射仪和能谱仪等对井下腐蚀产物进行分析.结果表明:腐蚀产物中的元素以Fe和O为主,主要成分为Fe3O4,注氮工艺过程中夹带的氧气是造成腐蚀的主要因素;根据氧的腐蚀机理,提出了针对氧腐蚀的对策,如改变制氮方式控制氧含量,选择合适材料,对井下金属设备采用涂层、缓蚀剂、阳极保护等防腐蚀方法.
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