As previously stated, the key issue relates to pipelines which cannot be internally inspected and the risk of corrosion, caused by disbondment of coating systems, primarily coal-tar enamel, on buried pipelines.
The standard approach to identifying and controlling metal loss on buried pipelines is to conduct in-line inspection (ILI) surveys. Where sub-critical defects are detected by ILI, the level of cathodic protection (CP) is managed in conjunction with Close Intervals Potential Surveys ‘(CIPS). Pipelines which cannot be internally inspected are managed through an “OLI4” survey which consisting of (CIPS) in conjunction with a coating defect survey e.g. Pearson or DCVG (Direct Current Voltage Gradient).
There are a number of limitations associated with current methodologies and this is of increasing concern as the asset ages. The SCT inspection system has the potential to identify defects and features which are currently not detectable using existing techniques thereby reducing the risk of failure on such pipeline systems.
A development project associated with SCT is underway NIA_NGGT0044, however it has been established that would be significant benefit to a more detailed look into comparing SCT data collected to data and conventional ILI data. As such this project, co funded by EPSRC is an industry sponsored CASE award targeting the sensitivity and specificity of the SCT technique. The student will use a mix of experimental and theoretical tools for the Non Destructive Testing (NDT) of ferrous materials and small laboratory based experiments will be used to inform much larger studies which will be performed on industrial test sites under the guidance of collaborators National Grid. The project is a collaboration of the School of Electronic and Electrical Engineering and the School of Physics within the University of Leeds.
Benefits
Publication of a technical paper / thesis on the work with discussions on the findings, recommendations and suggestions for further work.