Experimental Study on the Effect of the Water-Cut Conditions on the Performance of L80 Carbon Steel

Abstract

In the oil production, water and acidic gases, i.e., H₂S and CO₂, are co-produced with the oil. The acidic gases are known to associate with a variety of corrosion damage to the surface facilities leading to costly failures. Also, the acidic gases cause a reduction in the service life of equipment. Corrosion of API L80 tubular carbon steel in sweet media (in the presence of CO₂ gas) was investigated using the linear polarization resistance meter. Experiments using API L80 tubular carbon steel material were carried out in a stagnant flow condition with different ratios of produced water to crude oil at relatively high temperatures (60 °C up to 90 °C). The pressure was about 200 psi (13.8 bar) of CO_2, and the experiments were carried out using a high pressure vessel namely an autoclave cell. Under those experimental conditions, results indicated that at a temperature of 60 °C, the corrosion rate for carbon steel L80 increased as water-cut ratio increased. Also, the results showed that at higher temperature than 60 °C, the formation of iron carbonate scale on the surface of the steel was observed to increase. Consequently, the corrosion rate of the L80 carbon steel was observed to decrease.