常减压装置运行末期应对高盐重油水冲击的经验与措施

Measures Dealing with High-Water/High-Salt Crude Oil Shock at End of CDU Operation Cycle

详细阐述了某炼油厂2#常减压装置运行末期应对高含水、高含盐原油冲击的经验与措施,主要包括在原油水、盐冲击期间,电脱盐单元保证脱后原油水含量和常压塔保持稳定运行的操作方法,以及工艺防腐经验。在重质稠油大量带水期间,通过提高洗涤水水质,降低注入量;适当降低混合强度;优选破乳剂种类,提高注入量;调整电脱盐罐内油水界位等措施,稳定电脱盐运行,可切实减少常压塔的进水量。同时,原油携带水冲击进入常压塔时,降低原料进塔温度、确保全塔压降不超过21 kPa,可以确保常压塔整体运行平稳,各侧线油品质量总体受控;合理增大塔顶缓蚀剂、氨水注入浓度,保证塔顶不小于110℃,冷回流温度不低于90℃,强化顶循除盐设施运行,可以确保装置工艺防腐整体达到要求。

This paper describes the experience and measures of dealing with the shock of high-water and high-salt crude oil at the end of the operation cycle of the 2#atmospheric and vacuum unit in a refinery in detail,including the operation method of ensuring the water content of the de-water crude oil and the stable operation of the atmospheric unit after the shock,and the experience of anti-corrosion process.Since Tahe heavy oil carries a large amount of water,by improving the washing water quality,reducing the injection amount and the mixing strength,optimizing demulsifier type,increasing injection amount and adjusting the oil-water interface level in the electric desalting tank,it is feasible to stabilize the electric desalting operation and reduce the water intake of the atmospheric unit.When the crude oil carries water into the atmospheric unit,the inlet tower temperature of the raw material should be lowered.If the pressure drop of the whole unit is kept less than 21 kPa,the overall operation of the atmospheric unit is stable,and the oil quality of each side line is under control.Reasonably increasing the injection concentration of corrosion inhibitor and ammonia water on the top of the unit,keeping the temperature at top of the unit at not less than 110℃and the temperature of cold reflux at not less than 90℃,and strengthening the operation of the top circulation desalination facility,can ensure that the overall anticorrosion of the unit meet the requirements.