Characterizing Mechanical Damage with True UHR

Characterizing Mechanical Damage with True UHR

Third-party damage is a constant, unpredictable threat to your pipeline. An errant dig on a construction site or farm can compromise your pipeline’s integrity — no matter its age or condition.  No wonder pipeline operators rank third-party damage – also called mechanical damage – as their second most important pipeline integrity threat.* Legacy ILI systems can adequately identify deformations and deformations with metal loss, but what if you could confidently differentiate gouge-type metal loss (with or without associated deformation) from corrosion-type metal loss?

What is mechanical damage?

API 1163 defines mechanical damage as combinations of dents, gouges and/or cold work caused by the application of external forces. “External forces” frequently includes construction or farming equipment. All pipelines are at risk of encountering an external force like this at any point all along their length. There are four main types of mechanical damage, each posing its own challenge.

Plain dents: Plain dents do not have any associated metal loss. Plain dents can be found on the top side of a pipeline (between the 8 o’clock and 4 o’clock positions) or on the bottom side (usually at or near the 6 o’clock position). Bottom-side dents are commonly caused during construction when the pipe is laid on top of an object like a rock. Depending on their severity, plain dents tend to be less of an integrity threat compared to gouges or dents with gouges. With most rock dents, for example, provided the pipe and rock are in a stable position, there’s little risk of the injury worsening.

Gouges: Gouges occur when metal is mechanically removed from the pipe material. Gouges, with or without associated denting, are important integrity concerns because a gouge causes metallurgical changes to the pipe material. Gouges also have sharp edges, which facilitate the initiation of cracks, which can continue to grow with pressure cycling.

Dents with gouges: Dents with gouges are typically found on top of the pipe and are typically caused by third-party activity over the pipeline. Imagine an auger, bore or directional drill hitting the pipe, or a farmer running into it with a tiling machine.

Dents with coincidental corrosion: Dents with coincidental corrosion involve areas of metal loss that just happen to be in the same vicinity with a plain dent. An example could be internal corrosion, coincidental to a bottomside dent.

Differentiating deformations

Since not all mechanical damage is alike, it’s important to be able to tease out the nuance. Current state-of-the-art ILI systems can differentiate deformations, such as plain dents, from deformations with associated metal loss, such as a dent with a gouge or with coincidental corrosion. But they cannot differentiate gouge-type metal loss from corrosion-type metal loss.

In these cases, deformations with metal loss are assumed to be dents with gouges. Likewise, gouges without associated deformation may be treated as simple corrosion. This can lead to costly unnecessary digs or — perhaps more worrisome — not digging something that should be investigated. A missed gouge can experience crack initiation and can grow to failure with repeated pressure cycling.

True UHR from ENTEGRA^® allows for highly specific characterization of mechanical damage for detailed and accurate information that helps you make more informed pipeline decisions.

Seeing mechanical damage in True UHR

True UHR can differentiate gouges from corrosion, with or without any associated pipe deformation. This eliminates many potential false negatives — leading to possible missed leaks — and/or false positives, which could lead to unnecessary digs. This is possible through a combination of advanced MFL ILI technology and robust analysis that includes AI and the human-experienced based assessment by Level III data analysts.

Compared to status quo MFL ILI technology, ENTEGRA MFL ILI tools have double the number of MFL and caliper sensors and they capture data at much more than double the sampling rate. This allows ENTEGRA to gather enormous amounts of highly useful information in a single run. This data is then analyzed through a combination of proprietary, automated processes followed by in-depth review by our human analyst team. These analysts are highly experienced and trained to identify the nuances revealed by the abundant data captured in the ILI run. They look for patterns and signals that indicate mechanical damage events, distinguishing them from evidence of cold work, for example. Areas of potential concern are corroborated with additional sensor data sets to further discern possible mechanical damage from other causes, such as a manufacturing anomaly.

Even where a deformation is not present, the ENTEGRA UHR process allows for accurate POD, POI and sizing of gouges and can spot cases of coincidental corrosion in proximity to dents. The process also properly identifies plain dents that are unlikely to cause integrity issues, allowing you to move them down your watchlist.

Incidents of third-party damage may be unpredictable, but with True UHR from ENTEGRA, operators can have more confidence in their ability to understand mechanical damage and take informed action that keeps pipelines running safely and efficiently.

*According to 2019, 2021, and 2023 Kimberlite reports.