Effect of Water Content, Temperature and NaCl on CO2 Corrosion of Carbon Steel (A106B) in Iraqi Crude Oil

Abstract

An investigation was carried out to determine the corrosion rate of carbon steel (A 106 GradeB) as flow line in crude oil production with CO2 content employing three Iraqi crude oil (Kirkuk crude oil, Halfaya crude oil, and Rumalia crude oil) with identical produced water (brine) [1%NaCl,2%NaCl, and 3%NaCl]. Experiments were performed in an autoclave test apparatus, crude oilproduced water mixtures, water cuts were (0, 10, 20, 30, 40, and 100%), and temperature (20, 40, 60°C). For all experiments, CO2 partial pressure was maintained at 4bar and rotational speed 500 rpm. The corrosion rates were determined by the weight loss method. The results revealed that the corrosion rate of carbon steel increased by increasing water cut and temperature, but decreased with increasing salt concentration for all types of crude oil. Rumaila crude oil exhibited the highest corrosion rate and Kirkuk crude oil exhibits the lowest corrosion rate while Halfaya crude oil exhibits a moderate corrosion rate.

Keywords

• CO2 corrosion, carbon steel, crude oil, water cut, produced water, autoclave