Review of Volatile Corrosion Inhibitors Evaluation Methods and Development of Testing Protocols

Abstract Top of the Line Corrosion (TLC) is now known to be the main mode of failure in incidents associated with a number of wet gas pipelines operated all over the world. TLC is nevertheless a relatively recent phenomenon in a sense that its existence was only acknowledged about 10 to 15 years ago. Several research activities have been carried out since then to identify the main corrosion mechanisms and to propose appropriate mitigation techniques. Among them, the use of volatile corrosion inhibitors (VCI) seems very promising. However, the industry now suffers from a lack of consistency in the TLC inhibition evaluation methods. This paper presents a comprehensive and critical review of the different experimental setups proposed in the literature for the evaluation of VCI performances, highlighting benefits and drawbacks of each method. Building on this valuable experience, an effort is then made to propose a state of the art testing protocol for the determination of corrosion inhibition efficiency and persistency of VCI for TLC applications.