The exploitation of oil and gas in Brazil offshore fields requires constant technical improvements. Deeper wells, slightly sour environments and CO_2 partial pressures ranging from 80 psia to 150 psia lead to the use Corrosion Resistant Alloys as an alternative to carbon steels due to the relatively high corrosivity of the Brazilian fields. The manufacturing of a 13%Cr tubing in Brazil was considered. In order to prove the capability of this manufactured tubing, a qualification program was carried out. This qualification program was made in a cooperative work and it is described in this paper. Three main aspects were considered and are presented: the manufacturing process, the quality evaluation and product qualification and finally definition of the conditions on which the material could be used. One of the main requirements of the manufacturing process is its reproducibility. Reproducibility is affected by the quality of the raw material and the process variables that control the manufacturing process. The quality of the tubing is then assured by a number of tests that evaluate its performance. The tests set by this qualifying program involved mechanical properties and corrosion tests. Mechanical properties were evaluated by tension, impact (at 0 and -60°C) and hardness. Corrosion tests included autoclave corrosion tests as well as SSC susceptibility. Those testes were conducted in H_2S and CO_2 environments that simulated actual production environments. For the qualifying program four different runs of 13Cr tubing were tested. General corrosion and also susceptibility to localized corrosion (weight loss and crevice) were evaluated at 80°C, 100% CO_2 in chloride containing media. SSC tests were performed in up to 95% of the specified yield strength, in various sets of pH, H_2S and CO_2 partial pressures, NaCl concentrations and temperatures. Results clearly showed the adequacy of the material to be used and also the capability of the mill plant to keep the quality of the manufactured products.
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