Effect of solids precipitation and deposition of corrosion products on the protective ability of inhibitors

Authors: A.T. Faritov, L.P. Khudiakova, Yu.G. Rogdestvenskiy, А.А. Shestakov (GUP IPTER, RF, Ufa), S.N.Vagaytsev, A.V. Paripsky, M.F. Galiullin (Samotlorneftegaz JSC, RF, Nizhnevartovsk)

Key words: inhibition, internal corrosion, sediments and suspended solids.

The article presents of experimental determined quantitative loss of corrosion inhibitor as a result of adsorption on suspended particles of sand, calcite, clay and iron sulfide. The last two are particularly dangerous: clay can reduce the concentration of reagent in the solution at a concentration comparable to that of its, iron sulfide - the concentration of up to 20 times greater than self. Precipitation solids and sediments of the corrosion products lead to the formation of a potential difference between the surfaces of the metal under the deposition and without deposits. On the basis of experiments it is shown that when there is insufficient inhibition of metal deposition galvanic effect occurs. This effect can lead to accelerated corrosion of metal under the sediment. Thus, to improve the effectiveness of inhibitors should be cleaned pipes or choose inhibitors are able to penetrate through the sediments on the metal.