Comparison of Model Predictions and Field Data: The Case of Top of the Line Corrosion

Top of the line corrosion (TLC) is a specific type of corrosion that occurs due to internal water condensation in wet gas lines. It is a serious concern for the oil and gas industry and has been the cause of numerous pipeline failures. Many research projects have been executed with the aim of better understanding the mechanisms and developing accurate predictive models of TLC. Irrespective of their complexity, most of the models are based on laboratory experimental data. This makes it important, even in the case of most advanced models, to compare and validate a model’s predictions using field data. Data collected from sweet wet gas lines that experienced TLC issues were analyzed, processed, and then used as an input for a mechanistic TLC predictive model to simulate the evolution of temperature, pressure, water condensation rates, and TLC rate along the pipeline. The simulation results were then compared with in-line inspection (ILI) data. Challenges were encountered in the analysis of the field data due to their incompleteness, inaccuracy, and variability as well as in the processing of the ILI data. A coherent methodology for comparison with model prediction results was developed and described.