When iron sulfide (FeS) film coats a carbon steel surface, it can affect the extent of
corrosion and corrosion inhibition in several ways. A new laboratory experimental set up has
been designed and used to study such effects. The apparatus provides various techniques
of measuring the corrosion rate of FeS coated and uncoated steel surfaces in presence of
an oil/brine solution containing CO2 and H2S. The film is built in-situ by two distinct methods,
either through reacting the H2S present in the system with an iron chloride (FeCl2) aqueous
solution injected into the corrosion cell at a desired level, or by pre-corroding the steel
surface with a CO2/H2S saturated uninhibited brine. The newly designed set up was
validated in terms of the system dynamics, the iron sulfide film formation and deposition, the
H2S safety controls/monitoring and the corrosion measuring techniques installed in the
system.