Metallurgy Selection for Heavy Crudes with High Sulfur and High TAN

Over time, the exploration for crude oil to supply the world’s energy demands has resulted in drilling and producing ever heavier crude oils. These crudes come from a variety of locations including Venezuela and Canada among others. These crudes are high in sulfur and naphthenic acid (TAN) which can cause high corrosion rates especially at elevated temperatures. When processing these crudes in a refinery, it is critical that the proper metallurgy is selected to ensure long equipment life and high operating reliability. The metallurgy can vary from carbon steel, 5 chrome, 9 chrome, 316 and 317 stainless steel as well as Hastelloy C. This presentation provides a window into selecting the metallurgy for piping and equipment when processing high sulfur and high TAN crude oils. Real world examples for metallurgy selection for heat exchangers in the hot preheat train, crude heaters, and vacuum heaters as well as for crude tower and vacuum tower shells.