Flow dependence of steel corrosion in supercritical CO2 environments with different water concentrations

Corrosion Control in CO2 Enhanced Oil Recovery From a Perspective of Multiphase Fluids

“…It is quite possible that the water droplets or clusters present in the w/o emulsion and the water containing SC CO 2 (McGrail et al, 2009;Thanthiriwatte et al, 2012;Wang et al, 2013) result in the corrosion product particles on steel surfaces. As proposed by Liu et al (2018) in CO 2 fluid, the flow and wetting behavior of water clusters are the origin of corrosion damage. This mechanism could be extended to interpret the corrosion performance of steel samples in various electrolyte/non-electrolyte mixtures.…”

“…Corrosion inhibitors Process control CO 2 transportation Mild steel (e.g., 16 Mn) Effective in highly acidified, high pressure and high temperature conditions. (e.g., Xiang et al, 2017) Controlling impurity gases (de Visser et al, 2008;Sim et al, 2014b) Limiting water concentration (Sim et al, 2014b) Slowing down flow and pressurizing (Liu et al, 2018) CO 2 injection Mild steel (N80, P110) Stainless steel (304SS, 13Cr) Coatings or liners (IEAGHG, 2010) Injected with water slugs Reducing water/gas alternate frequency (Wang and Song, 2018) Oil production Mild steel (N80, P110) Stainless steels (304SS, 13Cr)…”

“…Recently, it was found that the corrosion morphology was highly relied on the flow rate and the degree of water saturation (Liu et al, 2018); a higher flow rate and a higher degree of water saturation produced larger corrosion product particles and patches, implying a possible corrosion mechanism related to the direct bombardment of water droplets on steel surfaces and these droplets are likely entrained in the dense CO 2 phase, rather than directly nucleated on steel surfaces. In SC CO 2 fluids, the entrainment of these water-rich clusters (or droplets) is possible and the presence of such water-rich heterogeneities in wet SC CO 2 has been identified by near-infrared spectroscopy (Wang et al, 2013) and radial distribution function method (Glezakou et al, 2010).…”

“…Here, these two cases can both be termed as water/non-electrolyte mixture. In a previous paper, Liu et al (2018) believed that the state of water in SC CO 2 phase might behave like the w/o emulsion or dispersion, where a corrosion mechanism was proposed in SC CO 2 environment regarding the impact of water droplets on steel surfaces. It implies that the density and velocity of water clusters in SC CO 2 phase determine the corrosion morphology.…”

“…Recently, several kinds of corrosion inhibitors were tested in simulated CO 2 injection or transportation conditions (Turgoose FIGURE 7 | The dependence of corrosion rate on water concentration in different electrolyte/non-electrolyte binary systems. The red solid square and the blue solid circle refer to the corrosion data in SC CO 2 environment according to Hua et al (2014a) and Liu et al (2018). The green open triangle and the black open rhombus refer to the corrosion rates in w/o emulsions or mixtures according to Sun et al (2016a) and Li (2009).…”