减氧空气驱集输管道抗氧缓蚀剂优选与评价

Optimization and Evaluation of Antioxidant Corrosion Inhibitor for Oxygen-reduced Air Drive Gathering&Transportation Pipelines

目前抗氧缓蚀剂存在种类稀少、单一种类缓蚀剂的性能不够好以及经济成本较高等一系列问题。为此,结合国内某减氧空气驱集输管道实际工况特点,通过对氧腐蚀机理研究,选取了3种现已研发的油田常用抗氧缓蚀剂EQI、HTT和TCT,对其进行了动态腐蚀评价试验和表面形貌分析,通过分子动力学模拟其在Fe表面的吸附情况,得到缓蚀剂分子在水溶液环境下对Fe基体表面的吸附能大小,结合对比分析模拟和试验的结果,筛选出缓蚀性能最佳的缓蚀剂。试验和模拟结果均表明:水溶液中3种缓蚀剂分子在Fe基体表面的吸附能大小从高到低依次为TCT>EQI>HTT,缓蚀剂分子吸附能越大,缓蚀性能越佳。所得结论可为减氧空气驱集输系统的腐蚀防护工作提供理论指导。

Existing antioxidant corrosion inhibitors are scarce in types,underperformed individually,and costly economically.Based on the actual working conditions of an oxygen-reduced air drive gathering&transportation pipeline in China,by analyzing the oxygen corrosion mechanism,three antioxidant corrosion inhibitors EQI,HTT and TCT commonly used in oilfields were selected for dynamic corrosion evaluation experiments and surface morphology analysis.Then,molecular dynamics simulation was conducted on their adsorption on the Fe surface to obtain the adsorption energy of the inhibitor molecules on the Fe matrix surface in water solution environment.Finally,combined with comparative analysis of simulation and experimental results,the inhibitor with the best performance was defined.Both experimental and simulation results show that the adsorption energies of molecules of the three inhibitors on the surface of Fe matrix in water solution are TCT>EQI>HTT in turn.The larger the adsorption energy of the inhibitor molecule,the better the mitigation performance is.The conclusions provide theoretical guidance for the corrosion prevention of oxygen-reduced air drive gathering systems.