Influence of Imidazoline Inhibitor on CO_2 Corrosion of N80 Steel in Annulus zone of Pump Recovery Well

摘要

The impact of CO_2 partial pressure ,fluid producing rate and corrosive medium on the CO_2 corrosion regularity of N80 steel and the inhibition efficiency of imidazoline inhibitor are investigated respectively through simulation of the actual working environment in the mined-out space of mechanical oil production wells by using high temperature and pressure reactor. According to the results, the corrosion rate of metals increases with CO_2 partial pressure but the inhibition efficiency of the inhibitor is hardly affected when CO_2 partial pressure in the scope of 1-3 MPa. The increase of the fluid producing rate will accelerate the corrosion of metals and the inhibition efficiency will decline. With corrosion inhibitor applied, metals corrode slower in the liquid phase than in the gas in the initial stage, but latterly the corrosion rate is gradually higher than that in the gas phase.