Unveiling the Real-World Performance of Volatile Corrosion Inhibitors (VCIs) for Top-of-the-Line Corrosion (TLC) Mitigation

Abstract TLC is a significant threat to pipelines in the Gulf of Thailand (GOT). Since 2016, VCIs have been implemented in the field following successful laboratory tests and are favored over traditional batch treatments for their continuous protection without production disruption. However, field data reveal inconsistent outcomes: while some pipelines achieve stable TLC control, others still suffer severe corrosion. This study reviews comprehensive field data, including operating conditions, in-line inspection (ILI) results, and VCI injection dosages to evaluate VCI effectiveness. Chemical vendors recommend VCI dosages of 350 ppm, significantly higher than conventional inhibitors. As many fields enter late life with increased water production, optimizing VCI dosages is essential to manage costs and adapt existing injection facilities. The study also addresses the debate on VCI effectiveness, highlighting discrepancies between laboratory tests and field performance, as laboratory efficiency tests may not fully replicate real field conditions. Through this analysis, we aim to provide insights into the actual performance of VCIs in GOT pipelines, offering valuable information for further development and improvement of TLC mitigation strategies.