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Corrosion Behavior of API 5L X65 Carbon Steel Under Supercritical and Liquid Carbon Dioxide Phases in the Presence of Water and Sulfur Dioxide

Depending on the capture process, liquid or supercritical carbon dioxide (CO2) can contain impurities like water (H2O) and sulfur dioxide (SO2), increasing the likelihood of corrosion of carbon ste...

Corrosion Behavior of Deep Water Oil Production Tubing Material Under Supercritical CO2 Environment: Part 1—Effect of Pressure and Temperature

The objective of the present study was to evaluate the corrosion properties of carbon steel in supercritical carbon dioxide (CO2)/brine mixtures related to the deep water oil production development. Corrosion tests were performed in 25 wt% sodium chloride (NaCl) solution under different CO2 partial pressures (4, 8, 12 MPa) and temperatures (65°C, 90°C). Corrosion behavior of carbon steel was evaluated using electrochemical methods (linear polarization resistance [LPR] and electrochemical impedance spectroscopy [EIS]), weight-loss measurements, and surface analytical techniques (scanning electron microscopy [SEM], energy-dispersive x-ray spectroscopy [EDS], x-ray diffraction [XRD], and infinite focus microscopy [IFM]). The corrosion rates measured at 65°C showed a high corrosion rate (~10 mm/y) and a slight difference with pressure. Under these conditions, the sample surface was locally covered by iron carbide (Fe3C), which is porous and non-protective. However, the corrosion rates measured at 90°C increas...

Corrosion Behavior of Deep Water Oil Production Tubing Material Under Supercritical CO2 Environment: Part 2—Effect of Crude Oil and Flow

Deep water oil production tubing materials are exposed to high carbon dioxide (CO2) pressure and temperature conditions that can affect the corrosion performance of such materials. The present stud...

Thiols as Volatile Corrosion Inhibitors for Top of the Line Corrosion

The effectiveness of hexanethiol, decanethiol, and 11-mercaptoundecanoic acid for CO2 corrosion inhibition of carbon steel exposed to top-of-the-line conditions has been investigated. Weight loss m...

Investigation of the Role of Droplet Transport in Mitigating Top of the Line Corrosion

The entrainment of liquid droplets, occurring in a limited range of gas and liquid flow conditions within the stratified flow region, could represent an effective way to transport a non-volatile li...

A FORMAÇÃO DA CAMADA PROTETORA DE FeCO3 E O CONTROLE DA CORROSÃO POR CO2 EM CONDIÇOES DE FLUXO TURBULENTO

The formation of a protective layer of iron carbonate (FeCO3) can reduce the rates of corrosion and prolong the useful life of carbon steel. However, turbulent flow conditions in this layer can easily be damaged and thus compromise the protection of the steel. In this work, will be presented a methodology based on the chemical aspects of the mechanism of formation of iron carbonate layer in a Thin Channel Flow Cell (TCFC). Electrochemical techniques were used to measure the corrosion rate and corrosion potential on the surface of steel API X65 exposed to aqueous solution of 1 wt.% NaCl purged with CO2 at 2 atm, pH 6.6 and 80°C in turbulent flow conditions. The surfaces and cross sections of the samples were characterized by means of Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDS) analysis. The results confirm the nucleation and growth of iron carbonate layer: the extension of supersaturation of the solution and the corrosion rate have decreased, and the corrosion potential has increased. The surface analysis showed dense and uniform FeCO3 layer with c.a. 20 µm thick after 120 hours in turbulent flow conditions.