At the Forefront of In-Line Crack Inspection Services: A Highly Versatile Crack Inspection Platform for Complex Flaw Morphologies and Absolute Depth Sizing

Abstract

In 2014, Enbridge published a request for proposals to develop and provide a solution on a specific type of long seam cracks in a 26” pipeline. In-line inspection technologies available at the time were not able to consistently and accurately characterize the crack threat, although the line was successfully hydrostatically tested in 2015. During the early stages of the project, NDT Global analyzed in detail Enbridge’s requirements, including the specific challenges, spool type, seam weld characteristics etc. and provided different proposals to Enbridge. In 2016, both parties signed a development contract to develop and build a 26” Next Generation Crack Inspection Platform (Proton). The project was divided into various stages to support a successful project that met performance requirements based both on pump tests and a field trial supported by investigative digs and coupon cutouts. The robot developed is a highly versatile crack inspection platform: it allows to be set up in a configuration optimized for the given threat, pipeline conditions, inspection speed and medium characteristics. This optimization of the configuration allows choosing the optimum measurement modes for flaws in the base material and in the seam weld independently. Additionally, the local wall thickness even in the seam weld is measured accurately. These capabilities allow the operator to collect the best data for each situation. Feeding the information into the crack management program allows Enbridge to maintain the target reliability of the asset. The robot was utilized successfully in the 26” pipeline. Processing, data analysis and reporting were performed within pre-agreed periods. Initial field findings and lab tests show high correlation of ILI and real flaws and proof the stated accuracy of the new service. The authors will present in detail some of the specific challenges of the pipeline system and limitations of available crack inspection technologies. Validation results from in-the-ditch non-destructive examination and destructive freeze breaks including cross sections from flaws with complex morphologies will be shown. Performance statistics and comparison to previous inspection results will be used to demonstrate that the new robot can be used as part of an effective crack management program.