Nitrogen Protection as Anticorrosion and Fireproofing Measure in the Use of Sour Crude Oil Storage Tanks

The results of using a nitrogen protection system for 15 years in a sour crude oil storage park equipped with Hazmat class II and III vertical storage tanks with a stationary roof without pontoons are analyzed. Under nitrogen protection conditions, the rate of localized corrosion of the inner surface of the roof of raw and commercial crude oil storage tanks is 0.013–0.015 mm/year, which is ∼100 times lower than the rate of corrosion under natural gas phase conditions inside the tank. Continuous operation of the nitrogen protection system ensures fire and explosion safety of the tanks. Interruptions in the nitrogen protection do not have any practical effect on the efficiency of through perforation of the roof until the end of the regulated service life of the tanks, but increase fire and explosion hazard due to the formation of pyrophoric corrosion deposits.