Influence of green inhibitor on flow-accelerated corrosion of API X70 line pipe steel in synthetic oilfield water

Inhibition effect of oleic acid hydrazide (OAH), a green corrosion inhibitor on API X70 steel in an Indian oilfield produced water was investigated for the first time under flow condition. The test was carried out at a more critical location (90-degree pipe elbow) in a circulating loop system with the fixed flow velocity. This location is deliberately chosen because, at this location, catastrophic failure of a low alloy steel piping system usually takes place under highly corrosive turbulent flow with higher wall shear stress and flow velocity. The corrosion examination was carried out by varying the concentrations (0.05, 0.15, 0.30 g L-1) of the OAH inhibitor under flow condition. The maximum inhibitor efficiency is found 87.7% at 0.30 g L-1 concentration. The formation of protective film was confirmed by SEM, XPS, Raman spectroscopy and FTIR spectra.