EFFECTS OF CEMENT CHEMISTRY, ADMIXTURES, AND INHIBITORS ON CORROSION PROTECTION OF STEEL PIPELINES BY INTERAL CONCRETE LINERS

摘要

Results are reported from a study focusing on the performance of concrete materials for internal pipeline protection against the erosive and corrosive effects of flowing brine. Seventeen different liner formulations were examined in this study. Corrosion rates were measured by linear polarization on samples exposed in a test manifold to flowing brine. Samples were also exposed to static site-generated brine as a function of time. These samples were returned to the laboratory for visual analysis of damage, examination of brine penetration through the concrete by electron probe microchemical analysis, and for measurement of changes in the concrete-liner interfacial shear strength. The study focused on the performance of two liners applied by centrifugal casting; an oil field-standard calcium silicate-based concrete, and a high sulfate resistance-calcium aluminate cement. The study also focused on a calcium-silicate concrete liner applied by hand. Results showed that standard calcium silicate concrete (API RP10E) and a rotary calcium aluminate concrete provided excellent protection. Pipewall corrosion rates were reduced from 10 to 15 mils per year to 1 mil per year or less. The hand-applied liners also reduced the pipewall corrosion rate, but not to the same degree as the cast liners. Further the risk of spalling of the hand-applied liner was judged to be greater than that of the cast liners, due to a lower measured pipewall-liner interfacial strength.