P. Altoe et al., EVALUATION OF OIL-FIELD CORROSION-INHIBITORS IN CO2 CONTAINING MEDIA - A KINETIC-STUDY, Electrochimica acta, 41(7-8), 1996, pp. 1165-1172
Film-forming corrosion inhibitors are extensively used to control CO2
corrosion of steel in oil and gas production plants. The performance o
f these inhibitors is connected to the persistence and/or regeneration
of the protective film. Their active mechanism in the presence of CO2
is still little understood as far as the kinetics is concerned. In th
is paper, some of the factors affecting this mechanism have been studi
ed with the aid of polarization curves and electrochemical impedance,
using rotating disc and cylinder electrodes. The performance of a comm
ercially available film-forming inhibitor used in PETROBRAS, the Brazi
lian petroleum company, was evaluated. The results show that the effic
iency of the inhibitor depends on its residual concentration and on th
e hydrodynamic flow conditions. The impedance diagrams provided inform
ation on growth, stability and deterioration of the inhibitor film.