This paper presents new applications of Volatile Corrosion Inhibitors (VCI) inside new and/or existing out-of-service pipelines. The system utilizes a combination of soluble and volatile corrosion inhibitors that are directly applied into the pipeline. In some cases, the decrease in the corrosiveness of environment is done by increasing the pH. Different approaches are discussed depending on pipeline design and operating considerations of the owner. A recurring issue during the construction and commissioning, and sometimes operation, of facility pipe (pump station and terminal) assets is the creation of internal corrosion threats due to leftover hydrotest water or product. Available methods for removing the water or product entirely, or applying inhibitor chemicals to the hydrotest medium or product, are time-consuming and expensive. In 2015, 2016, and 2017 VCI chemicals were applied to various facility piping systems in lieu of other methods which would mitigate internal corrosion threats. This method, while not a best-practice in the oil and gas industry at the time, was shown through laboratory testing to be effective at mitigating both biological and generalized internal corrosion. The application of VCI was also proven to be safe for the personnel involved, which was one of the original objections of the operator, and the application process resulted in significant cost savings at the time of commissioning. This paper details a single preservation project as an example.
Key words: volatile corrosion inhibitors, VCI, pipeline, corrosion protection, internal corrosion, microbiologically inducted corrosion, MIC, hydrotest, out of service