Author(s)

Apolinar Albiter

Instituto Mexicano del Petróleo, Ciudad de México, México.

In the oil and gas industry, it has been established that for pipelines fabricated with carbon steels, their limitation is related to H₂S and CO₂ environments, which is 7 to 10 psia of partial pressure of CO₂. Therefore, in carbon steel cracking is shown, after 7 or 10 psia of partial pressure of CO₂. The experimental work was performed under static conditions in autoclaves within a pH of 3 to 3.8; partial pressures of 16 - 96 psi for H₂S and 15 - 53 psi for CO₂, in the temperature range of 25°C - 150°C. It was observed that the average yielding stress used in Sulfide Stress Cracking (SSC) tests decreases with temperature increment. Hydrogen Induced Cracking (HIC) evaluations showed that X52 steel, under conditions, was not susceptible to HIC. Results of SSC did not show indications of cracking after exposure to sour solutions, except for the specimen exposed to high H₂S and CO₂ content (96 psi of H₂S and 53 psi of CO₂ of the partial pressure) and high temperature (150°C). Microcracks located between the upper and lower weld beads were also observed. However, the highest average corrosion rate was 0.27 mm/year (10.6 mpy), which occurred in samples exposed to 96 psi of H₂S and 53 psi of CO₂ at 150°C. Likewise, the highest localized corrosion (severe pitting attack) was obtained at the same environment with a corrosion rate of 4.2 mm/year (167 mpy). The oil and gas industry could use carbon steels pipelines in partial pressure higher than 10 psia.

Sulfide Stress Cracking (SSC), Hydrogen Induced Cracking (HIC), Pitting, Welding, X52 Steel

Albiter, A. (2020) Sulfide Stress Cracking Assessment of Carbon Steel Welding with High Content of H₂S and CO₂ at High Temperature: A Case Study. Engineering, 12, 863-885. doi: 10.4236/eng.2020.1212061.