Threat Awareness: Corrosion Growth

Corrosion is a natural process and one of the primary threats to pipelines. Because it is a time-dependent threat, managing corrosion growth requires more than a single assessment to gain predictive insights into future pipeline integrity.

In this video, Integrity Engineering Solutions team members Ricky Ramon and Callie Lamb share more information on corrosion growth and how TDW helps customers assess corrosion and make a plan for the future.


Today, we're going to talk about growth threats that impact future pipeline integrity. Monitoring immediate threats is important, but operators should also be vigilant for future integrity threats. For example, understanding corrosion growth over time gives operators insight into pipeline asset longevity.

What is corrosion and how is it detected?

Corrosion results from a reaction with the pipeline environment causing metal loss and reducing the strength of the pipeline. The way we detect corrosion is by using our magnetic flux leakage tools or the SMFL. ILI tools don't detect corrosion directly. They detect metal loss caused by corrosion, and we estimate the amount of metal loss based on the anomaly's geometry.

Why measure corrosion over time?

While there is value in understanding the current state of the corrosion on the pipeline, there is additional value in knowing the rate at which that corrosion is growing. Knowing more about the growth rate gives operators the ability to make better decisions and plan for the life of the pipeline.

How is corrosion growth assessed?

We break it down into three levels of analysis Level one, we calculate statistical corrosion growth rate from a recent inspection. This assessment is typically used to determine if the pipeline is fit for service at the current time of inspection and operating condition.

Level two is a quantitative approach where metal loss anomalies are aligned between two ILI runs. Corrosion growth rates are derived from the changes in anomaly dimensions and depth over time.

Level three goes a step further by adding a qualitative approach. The level three analysis provides a more complete picture because it utilizes raw TDW signal-to-signal data to visually verify if an anomaly has grown over time. Once the analysis is complete, we will recommend a re-inspection interval and provide a schedule for both immediate and future repairs.


Our innovative ILI technologies combined with our dedicated integrity engineering group are helping operators around the world extend the life of their assets. If you have any questions about corrosion growth or other threats, the IES team is here to help.