Corrosionfracture kinetics in welded pipes in chlorine-saturated carbon dioxide oilfield media

Bypass tests of Ø219×8mm 13KhFA, 08KhMFChA, 20-ksh (steel 20 corrosion resistant cold resistant) and Grade steel piping spools were carried out on an oil-gathering line one the oilfields in Stavropol region. Tubing condition was checked after 7, 15, 17 23 months testing. After two years service no change found mechanical properties base metal or weldments manufactured from 13KhFA 08KhMFChA steels. It has been demonstrated that formation chromium-containing phase products inhibits penetration chlorine ions corrosive media to surface thus reduces rates. Estimated, laboratory comparison passivation coefficients have proposed. These make it possible predict level self-passivation with regard operating conditions particular oilfields.