The atmospheric corrosion of Mg and MgAl alloys was investigated. Corrosion tests were performed in the laboratory under controlled environment. CP Mg, AM50 and AZ91 samples were exposed at 95% RH and 22°C in the presence and in the absence of 400 ppm CO2 for 24 h to 672 h. The passive film was characterized by means of XPS, FTIR, AES and XRD. The film consisted of MgO/Mg(OH)2 with carbonate on...

Erosion, corrosion, and erosion-corrosion are common problems in offshore pipelines, tubing and pipe fittings. Corrosion has an important impact on the total cost of oil and gas production. Considering the diversity of corrosion related problems, CO2 corrosion (sweet corrosion) is probably the material degradation mechanism most extensively assessed in this industry over the last 30 years. In t...

Water wetting is a crucial issue in carbon dioxide (CO2) corrosion of multiphase flow pipelines made from mild steel. This study demonstrates the use of a novel benchtop apparatus, a horizontal rotating cylinder, to study the effect of water wetting on CO2 corrosion of mild steel in two-phase flow. The setup is similar to a standard rotating cylinder except for its horizontal orientation and th...

In this paper a two-dimensional (2-D) stochastic localized CO2 corrosion model is proposed, which describes the balance of two processes: corrosion (leading to metal loss) and precipitation (leading to metal protection). The model is able to predict localized corrosion of carbon steel in CO2 containing environments. The model uses corrosion rate and surface-scaling tendency predicted by a 1-D m...

Liquid water and CO2 can easily lead to carbon steel corrosion, especially at high pressures. Corrosion can happen either during normal running or during pressurized standstill conditions. The present paper describes three real cases of gas lift compressors operating in offshore platforms that suffered internal damage due to the formation of carbonic acid and unfavorable process conditions. The...

This paper covers one of the building blocks required to complete a mechanistic CO2 / H2S corrosion model: electrochemistry of carbon steel CO2 corrosion in the presence of traces of H2S (3-250 ppm in the gas phase). Electrochemical impedance spectroscopy and linear polarisation resistance were used to investigate the mechanism of CO2/H2S corrosion in a glass cell at room temperature, at atmosp...

The carbon dioxide corrosion electrochemistry of mild steel has been studied in the presence of high CO2 partial pressures and acetic acid (HAc). Potentiodynamic sweeps, linear polarization resistance (LPR) and weight loss (WL) experiments have been conducted to investigate the effects of flow velocity, CO2 partial pressure, and acetic acid concentration on the corrosion rate of mild steel. Ele...

Internal corrosion is a common problem in pipelines transporting oil and gas containing corrosive components such as CO2 and H2S. In many mature oil wells, the water cut and CO2 content may reach high level which forms a suitable environment for initiation and growth of corrosion. To avoid the consequences of corrosion, process parameters should always be controlled within safe operating limits...

The effect of an inert solid deposit on uniform CO2 corrosion of mild steel is modeled based on a mechanistic electrochemical CO2 corrosion model. Laboratory testing has shown that the dominant factors introduced by the inert solids deposit are related to surface coverage, where both anodic and cathodic reaction rates are decreased because of less active surface area being exposed. The inert so...

The role of sodium chloride (NaCl) particles and ammonium sulfate ((NH4)2SO4) particles on the initial atmospheric corrosion of copper and zinc was investigated under in situ and ex situ conditions using microgravimetry, FTIR spectroscopy, ion chromatography, scanning electron microscopy with x-ray microanalysis and the scanning Kelvin probe. For the first time, in situ infrared spectra were co...