Characterization and potential distribution mapping of cathodically protected buried pipelines based on homogeneous and heterogenous factors

Résumé fourni par la source

The use of a close interval potential survey (CIPS) for cathodically protected buried pipelines can provide useful information about the active or passive state of the pipeline/coating interface and the level of protection. Various models have been used to describe the potential distribution for these systems under the assumption that the coating characteristics and soil conditions are homogenous over the selected Right of Way. To allow for the inherent heterogeneity of these parameters, a transmission line model (TLM) was developed to determine the potential distribution along the soil-pipeline interface numerically. Numerical analysis of the TLM showed the model's sensitivity for both heterogeneous and homogeneous soil and coating conditions, such as different impedance and current leakage. For validation of the model, the model’s output was compared to measured CIPS values for various impressed current cathodically protected buried pipelines. The model’s output was able to follow the general trend of the field CIPS data. This provides insight into the distribution of coating impedance along the length of the two pipelines. Two case studies were performed to show the impact of various environmental and/or physical factors that can affect the effectiveness of a cathodic protection system. It was shown that the model could be used to either extract the state of the coating, helping to identify possible regions of low impedance which could be attributed to holidays/defects present in the coating from CIPS data, or if given real-world factors, it can be used for the design and integration of cathodic protection (CP) systems.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.