目的 为解决油田现场尿素辅助稠油蒸汽吞吐环境中使用的N80钢油套管管柱的尿素腐蚀问题。方法 采用动态高压釜模拟尿素辅助蒸汽吞吐采出井的井筒工况环境，借助扫描电子显微镜(SEM)、能谱分析仪(EDS)、X射线衍射仪(XRD)、X射线光电子谱仪(XPS)表征技术，研究了N80钢在不同浓度尿素溶液中的腐蚀特性。结果 结果表明，高温蒸汽环境中尿素溶液对N80钢的腐蚀是活化腐蚀、均匀腐蚀，表面腐蚀产物主要组份为FeCO3，且随着尿素溶液浓度的增大，腐蚀产物膜厚度增加，膜厚增长速率减小，对N80钢的腐蚀愈严重。对尿素辅助稠油蒸汽吞吐采出井井筒而言，在有原油存在下30%浓度尿素溶液中，由于原油起到了缓蚀剂作用，不会形成严重腐蚀，且随着原油量的增加，对N80钢的平均腐蚀速率降低。对于尿素辅助蒸汽吞吐提高采收率技术而言，在满足井筒腐蚀控制要求的前提下，现场试验方案的尿素溶液浓度可以高达30%。结论 N80钢能够满足尿素辅助稠油蒸汽吞吐采出井井筒腐蚀控制要求，可以安全使用。

In order to solve the urea corrosion problem of N80 steel oil casing string used in urea assisted heavy oil steam huff and puff environment in oilfield, the urea corrosion experiment was carried out by high temperature and high pressure dynamic corrosion kettle experiment system to simulate the wellbore working environment of urea assisted steam huff and puff production wells. Before the experiment, 1 L of urea solution of different concentrations was predeoxygenated by N2 at room temperature for 4 h. A set of 3 pieces of 50 mm×10 mm×3 mm hanging sheet samples processed from N80 steel was put into the high temperature autoclave, and the pre-deoxygenated solution and crude oil were imported into the kettle. The deoxygenation continued for 2 h before all valves were closed. The stirring speed was set to 1 000 r/min to start the experiment. During the experiment, the kettle was heated up as it was stirred, and the temperature was heated up to 150 ℃ to keep warm until the pressure gauge reading did not change. After the urea in the solution was completely decomposed, the temperature was then reduced to the experimental temperature (50 ℃ and 80 ℃). When the temperature reached the experimental temperature, the experimental time was recorded, and the experimental period was 240 h.