MISTRAS member-company Onstream recently began offering a new advanced solution for their inline inspection (ILI) offerings: signal-to-signal corrosion growth matching.

Post-inspection enhanced analysis services can provide pipeline operators with additional information to support critical integrity decisions. These services go beyond typical inline inspection reports to provide enhanced assessments such as dent strain and restraint, bend strain, and pipeline movement. Determining accurate corrosion growth rates has historically been challenging based on the comparison of one pipeline inspection report to another. Traditional methods rely on “box matching”, whereby the inspections are aligned in a spreadsheet or database, and then the depth difference in the reported anomalies is used to estimate corrosion growth rates. This method can result in wide growth tolerances, which often translate into very conservative growth estimations and excessive digs in some cases. Significant enhancements to corrosion growth assessments are now available using the comparison of raw signal data from one inline inspection to the next.  

Going beyond traditional methods of defect “box-to-box” matching methods, “signal-to-signal” corrosion growth assessment services take successive data sets and align the two inspections in terms of weld and anomaly signatures, normalize the tool readings at each joint to compensate for changing run conditions or tool variations, and then resize matched anomalies with the same algorithms and methodology to remove analysis and run condition biases. Signal-to-signal corrosion growth rate analysis, performed by our team of experts, is a pure comparison of raw ILI signal data lauded for its high accuracy. It directly compares a raw signal magnetic flux measurement to another raw signal measurement. This is performed with our analysis software and requires both signals to come from the same vendor and ILI tool. This helps pipeline operators take the uncertainty out of corrosion growth rates and makes for more accurate data that can help support pipeline integrity optimization.

Onstream offers advanced ILI and pipeline data services for small and large diameter pipelines using ultra-high-resolution combo magnetic flux leakage (MFL), geometry, and Inertial Mapping Unit (IMU) technology. To learn more about signal-to-signal corrosion growth matching, click here