【摘要】 为保障CO₂驱油、海洋油气开发等特殊工况下油气井的开采安全并延长油套管服役寿命，亟须明确极端低温环境（≤-20℃）对油管钢腐蚀行为的影响规律。采用现场油管钢为实验材料，通过腐蚀失重测试、腐蚀产物表面及截面形貌观察以及腐蚀产物成分分析等方法，系统研究了油管钢在低温环境下的腐蚀行为。结果表明，两种温度环境下腐蚀产物主要成分均为FeCO₃。油管钢在低温环境下随着浸泡实验时间的延长，腐蚀速率先快后慢，逐渐下降趋于平稳。低温环境下油管钢的腐蚀行为与常温下有着明显的区别，常温环境下油管钢更倾向于均匀腐蚀，点蚀坑呈浅碟型（深度集中在10～20μm）；在低温环境下，腐蚀形态转变为以点蚀为主导，且点蚀坑倾向发展为深孔型（深度集中在20μm以下），表现出更强的局部侵蚀性。低温环境并未抑制油管钢的腐蚀进程，反而促使腐蚀形态向局部纵深发展，腐蚀行为的复杂性和不确定性显著增加，对油套管服役安全构成严峻威胁。更多还原

【Abstract】 To ensure the safe operation of oil and gas wells under special conditions,such as CO2-enhanced oil recovery and offshore oil and gas development,and to extend the service life of casing and tubing,it is essential to understand the impact of extreme lowtemperature environments（≤-20℃）on the corrosion behavior of tubing steel.Utilizing field-sourced tubing steel as experimental material,this study systematically investigates the corrosion behavior of tubing steel under low-temperature conditions,employing methods such as corrosion weight loss test,surface and cross-sectional morphology and composition analyses of corrosion products.The results indicate that FeCO3 is the primary component of corrosion products in both temperature environments.Under low-temperature conditions,the corrosion rate initially increases and then gradually decreases,eventually stabilizing with prolonged immersion.The corrosion behavior of tubing steel at low temperatures differs markedly from that at ambient temperatures.At ambient temperature,tubing steel predominantly undergoes uniform corrosion,with pitting lesions forming as shallow,dish-shaped pits(depth in the range of 10-20μm).Under low-temperature conditions,the corrosion morphology is dominated by pitting corrosion,with the pits tending to develop into deep,hole-like structures(distributed mainly below20μm in depth),exhibiting more pronounced localized corrosion.The low-temperature environment did not suppress the corrosion process of tubing steel;rather,it promoted the development of localized corrosion in depth.The complexity and uncertainty of the corrosion behavior significantly increased,posing a substantial threat to the service safety of oil casing and tubing.更多还原