Finer grade selection shall take into account other parameters such as Chloride content and in-situ pH.
OCTG carbon steels are known to corrode when exposed to wet CO2 containing environments: they will suffer from various forms of corrosion such as general metal loss corrosion or localized corrosion (pitting, crevice, Mesa attack).
Martensitic steel has proved to be the most cost effective solution to protect against wet CO2 corrosion in oil &gas wells.
Comparison of Cost vs time for Carbon steel + inhibitors (+ workovers) and for 13%Cr steel in wet CO2 well
VM 90 13CR offers greater minimum yield strength (90 ksi), tighter chemical composition, finer grain size, and more stringent inspection requirements than API 5CT PSL 2 for L80-13CR:
VM 90 13CR is also available with High Collapse performance (VM 90 13CRHC).
Resistance to SSC (Sulfide Stress Cracking)
VM 90 13CR resistance to SSC is limited to small amounts of H2S and also depends on in-situ pH and chloride. Contact your Vallourec representative for more SSC and corrosion test data on 13CR steels.