Corrosion resistance assessment of P110 SS and 2205 DSS materials in extreme Iraqi oil wellbore environments: a comparative study and microstructural analysis

Purpose This study aims to evaluate the suitability of P110 stainless steel (P110SS) and 2205 duplex stainless steel (2205 DSS) for use in production wellbores subjected to extreme conditions in an Iraqi oil wellbore environment. These conditions include high CO 2 and H 2 S partial pressures, elevated temperatures, salinity and moisture content, which pose significant challenges to material performance. Design/methodology/approach P110SS and 2205 DSS were selected based on industry references, usage and manufacturer recommendations. Testing was conducted in a controlled environment that simulated the extreme conditions of an oil wellbore, varying CO 2 and H 2 S partial pressures to mimic field conditions. Corrosion rates were measured, and material degradation was further analyzed using scanning electron microscopy, energy-dispersive spectroscopy and X-ray photoelectron spectroscopy (XPS). XPS provided detailed insights into the surface chemistry, oxidation states and passive film integrity, allowing a comprehensive understanding of corrosion mechanisms. Findings The results showed that P110SS experienced a higher corrosion rate, making it less suitable for extreme conditions. XPS analysis confirmed the presence of Fe 3 O 4 , Fe 2 O 3 , FeS and FeCO 3 corrosion products, indicating significant oxidation and sulfidation. However, its use may be justified economically if paired with a corrosion inhibitor. On the other hand, 2205 DSS exhibited a significantly lower corrosion rate, with XPS revealing a stable passive layer consisting of Cr 2 O 3 , FeOOH and Fe 2 O 3 , making it a more reliable material choice for such wellbore environments. Research limitations/implications This study focuses on the corrosion behavior of (P110SS) and (2205 DSS) under simulated extreme conditions in an Iraqi oil wellbore environment. While the findings provide valuable insights, the controlled laboratory environment may not capture all variables present in real-world wellbores, such as varying operational conditions and chemical interactions. Future studies could expand on this work by including long-term field testing to validate the materials’ performance in actual wellbore environments, accounting for additional factors like fluctuating pressures and temperatures. Practical implications The study’s findings are based on controlled laboratory simulations of extreme wellbore conditions, which may not fully replicate the complexity of real-world oil well environments. Variables such as fluctuating temperatures, pressures and chemical interactions in actual wellbores may influence material performance differently than observed in the controlled tests. In addition, long-term exposure and operational stresses experienced in real oilfield applications were not considered. As a result, the practical applicability of the findings may require further validation through field testing and evaluation under varying operational conditions. Social implications The social implications of this study, while not directly addressed, could be inferred in terms of its potential impact on the oil industry and related communities. By improving material selection for oil wellbores, the study contributes to safer and more efficient oil extraction processes, which can reduce the risk of environmental damage due to material failure or corrosion-related incidents. Originality/value This study provides new insights into the corrosion resistance of P110SS and 2205 DSS under harsh oil wellbore conditions. By integrating XPS surface analysis, it offers a more precise understanding of the chemical composition and stability of corrosion byproducts, contributing to the field of material selection for oil reservoirs and suggesting potential solutions for enhancing the durability of wellbore materials.