Session: 03-03-02 Assessment Model Enhancements Other Threats - Part III

Paper Number: 87194

87194 - Enhancing Results of Ultra-High-Resolution Axial Magnetic Flux Leakage (MFL-A Ultra) Inspection Data Utilizing Finite-Element Modeling (Fem) Simulations 

The standard evaluation methods for MFL-A inspections are based on calibration approaches that utilize a simple set of parameters, like length, width and depth. This leads to stable results as long as the corrosion tends to be isolated. In aging pipeline systems, corrosion is getting more complex, which requires more sophisticated sizing methods to avoid outliers in depth sizing.

This paper presents a method that utilizes FEM simulations on ultra-high-resolution MFL-A data. It follows two main aspects.

The first aspect is to learn from dig verifications by using laser or ultrasonic scans of corrosion anomalies as geometry input data for a finite-element model to simulate the corresponding magnetic flux. The resulting simulated magnetic flux is then confirmed by the magnetic flux measurement of the ILI tool. This way the simulation model is validated.

The other aspect is to apply the achieved insights as a new depth sizing concept: the complete corrosion geometry as indicated by the ILI measurement is put into the validated FEM model to simulate the magnetic flux that should correspond to the one measured by the ILI tool.

In this new sizing method the influence of complex corrosion is considered, as all surrounding features are part of the model. Several models are calculated in order to minimize the impact of ambiguity of depth results. Potential outliers of the standard, calibration-based sizing method, which are caused by a challenging signal interpretation and increased ambiguity, can be identified and more effort can be spent in those to improve the quality of these results. This increases the accuracy and, ultimately, stabilize pipeline operators’ integrity assessments.

In the big picture, novel approaches to MFL-A data interpretation, such as FEM, empower operators to make more informed decisions specific to their asset integrity management programs while reducing the costs, uncertainty and conservatism associated with these decisions.

In the future the presented approach has to go hand in hand with complementing methods like combining with either ultrasonic inspection data or circumferential MFL data (latter one also called Deep Field Analysis) to even further enhance the characterization and sizing of corrosion anomalies.

Presenting Author: Edgar Schneider ROSEN

Presenting Author Biography: Dr. Edgar Schneider has studied Geophysics in Göttingen, Germany and received a doctorate with a topic about magnetotellurics in 2002. Working for ROSEN since 2003, he gained experiences with magnetic inline inspection (ILI) systems in various positions from development, technical support, evaluation and management. In recent years he was dedicated to bring finite element simulation into daily data evaluation practice. Current function is lead process professional for ultra-high resolution axial MFL ILI service.