Root-cause analysis identified the most likely source of corrosion to be the presence of H2S
During the fabrication of the subsea boarding valve skid for a major offshore platform in the Gulf of Mexico, the fabricator purchased several large forgings. These large forgings, from 8” to 12” in diameter, were to be machined into block valve bodies rated to 15,000 psig. As part of the agreed-upon Inspection and Test Plan, the mill certificates for the forgings were reviewed by the fabricator and by the company inspector.
Multiple failures from upstream wells and gathering lines and downstream processing facility, leads to a total systems approach to integrity management