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The Corrosion Center Joint Industry Project (CC-JIP) at the Institute for Corrosion and Multiphase Technology includes a variety of active projects, with a number of new projects being planned.

The CC-JIP is the original research group of the Institute. Our many sponsor companies obtain first information on research and rights to corrosion prediction software produced under this program, after minimum requirements are met.

Representatives from each member company are invited to the semi-annual advisory board meeting to review current research through presentations, tour the facilities, and provide research direction for future testing.

Please contact Bruce Brown for more information on the CC-JIP.

Goals

To increase knowledge and understanding of internal pipeline corrosion through definition of the problem through theory and testing.

To provide new engineers to the field of corrosion who have had experience with the tools and theory of the corrosion process.

To provide a mechanistic model to document the progress and understanding of the corrosion processes encountered in internal pipeline corrosion.

Deliverables

Tangible

• Biannual reports
• Software package (MULTICORP corrosion prediction software)
• Young engineering graduates fully trained in corrosion

Intangible

• Improved understanding of internal pipeline corrosion
• Improved communication and coordination between experts in the field from all the major oil and gas and inhibitor companies

Current CC-JIP Projects

Modeling of Sour Corrosion

Advancement in understanding of the corrosion mechanisms related to H₂S corrosion environments enabled the development of an integrated electrochemical model for H₂S/CO₂ uniform corrosion, including the effect of H₂S on the protective corrosion product formation on mild steel. The latest model of uniform H₂S/CO₂ corrosion of carbon steel accounts for the key processes underlying corrosion: chemical reactions in the bulk solution, electrochemical reactions at the steel surface, the mass transport between the bulk solution to the steel surface, and the corrosion product formation and growth (iron carbonate and iron sulfide).

The Role of Polysulfides in Localized Corrosion of Mild Steel

It鈥檚 well known that polymorphous iron sulfides can form on a steel surface as corrosion products in H₂S corrosion of mild steel. Rather than only as a diffusion barrier and surface blockage, the influence of the polymorphous iron sulfide layer on the corrosion of the steel underneath has been observed in experiments. This impact of iron sulfide polymorphism on the corrosion process is hypothesized to be due to different physicochemical properties associated with different phases of iron sulfides.

H₂S/CO₂ Corrosion in Slightly Sour Conditions

Research programs are examining corrosion under slightly sour conditions to identify the environmental parameters with the most influence on general and localized corrosion. H₂S at low concentrations has been believed to have a positive effect on decreasing the general corrosion rate of carbon steel as a layer of mackinawite is considered to be formed on the surface after exposure to aqueous H₂S. However, dependent upon the environmental conditions, this layer may or may not have protective properties. Previous research of localized corrosion that occurred in slightly sour conditions in a large-scale flow loop under single-phase and multiphase flow has been used to develop a better understanding of how bulk solution conditions can affect the growth of the corrosion product layers over time and their relationship to localized corrosion. Further studies in sour conditions continue toward understanding the effects of flow on the corrosion product layer and the initiation of localized corrosion.

H₂S Corrosion Electrochemistry

This project investigated the electrochemical behavior of carbon steel corrosion in H₂S environments. Uniform H₂S corrosion mechanisms were experimentally studied in short term corrosion experiments before any significant interference from iron sulfide corrosion product layers occurred. Mechanisms related to H₂S/CO₂ corrosion were investigated using potentiodynamic sweeps with comparison to electrochemical modeling. The final electrochemical model would be used to predict the effect of temperature, pH, pH₂S, and flow on corrosion mechanisms of mild steel in aqueous solutions containing H₂S in the absence of protective iron sulfide layers.

High Temperature Corrosion in a Sour Environment

Investigation of the effect of temperatures up to 250C on H₂S corrosion of mild steel will be focused on understanding the kinetics of iron sulfide formation at high temperatures in aqueous environments and developing a corrosion prediction model for an H₂S/CO₂environment.

Evaluation of Wall Shear Stress in Multiphase Flow

Wall shear stress (WSS) is one of the most important parameters used to characterize flow conditions and to assess the influence of flow on corrosion. However, the effect of turbulence and mechanical forces produced by flow on corrosion product layers and inhibitor films is not fully understood. This study uses controlled laboratory conditions in large scale flow loops to determine the magnitude of WSS for a wide range of gas-water flow regimes (stratified flow, slug flow, and annular flow) using a direct WSS measurement probe, pressure drop measurements, and flow rate measurements including visual observations by a high-speed camera.

Electrochemical Modeling of Corrosion Inhibitors

Mitigation efficiencies obtained from corrosion inhibitor adsorption isotherms can be related to the change of individual charge transfer and mass transfer corrosion mechanisms. Assuming that efficiency is related to surface covered by the inhibitor, the individual retardation of the corrosion mechanisms (anodic and cathodic reactions) can provide valuable information used to mathematically model the effect of a specific inhibitor in sweet and sour environments.

Iron Carbide Development and its Effect on Inhibitor Performance

The purpose of this study is to develop an understanding of how iron carbide layers, derived from the different microstructures of carbon steels during corrosion, affect corrosion behavior and inhibitor performance.