Elemental sulfur deposition commonly occurs in sour gas pipelines, especially from high H2S reservoirs.
In aqueous environments, contact of solid sulfur with mild steel can result in aggressive corrosion due
to sulfur’s oxidizing capability. Iron sulfide is formed on the internal pipeline surface as a corrosion
product of carbon steel in an environment containing H2S. Corrosion caused by deposited elemental
sulfur can be further accelerated in the presence of iron sulfide due to its semiconductive nature.
Currently, there is minimal prior literature on the corrosion caused by the deposition of both iron sulfide
and elemental sulfur in combination. This study was performed to further investigate the effect of iron
sulfide and elemental sulfur corrosion of mild steel using an autoclave design to simulate an underdeposit
corrosion mechanism. The development of a new effective inhibitor for corrosion and pitting
protection in the presence of sulfur and iron sulfide under sour conditions will also be described.