In this paper, high-temperature and high-pressure corrosion test was used to
simulate the corrosion process of multi-component thermal fluid (CO2/O2/H2O)
on oil pipes (N80 steel), casings (J55, TP90H, P110 steel, and
transportation pipelines (20# steel) in the process of CCUS technology
application. The results show that during the entire corrosion process, the
oil layer casing and surface casing are corroded most seriously in this
environment, and the corrosion forms of these five steel materials in the
CO2/O2 environment are uniform corrosion and local corrosion, and the
corrosion products mainly consist of FeCO3, Fe2O3, Fe3O4 and FeOOH crystals.
These oxides form a double-layer film structure on the surface of the steel.
The inner layer is denser and consists mostly of FeCO3 crystals, which has
better protection against further corrosion of the internal steel. The outer
layer is loose and porous, and its components are mostly FeCO3 crystals.
Fe2O3, FeOOH, Fe3O4 and FeCO3 crystals, have poor corrosion protection for
internal steel. Due to the difference in corrosion products of the inner and
outer film layers, relatively obvious local corrosion appeared on the
surfaces of the 5 steel materials.