Operating reliably and responsibly

Using robotic tools for challenging inspections

Distribution pipelines often have smaller diameters, sharper bends and more branches than transmission pipelines, adding complexity to ILI practices.

Conventional ILI technologies can move through pipelines free-swimming but require two different points for launch and retrieval. We have begun using robotic “crawling” ILI tools that can be launched and retrieved from the same point. Equipped with a camera, they can detect and move around obstacles, avoid branches and navigate through sharper bends.

In 2025, we inspected five distribution pipelines (totaling a distance of 17.9 km (11.2 miles) across Ontario using these specialized ILI tools. We’re using the results from those inspections as part of the integrity program to assess the reliability for similar pipes.

Developing a custom tool to detect corrosion

Building on our continuing use of crawling ILI tools, in 2025 we partnered with an external vendor to develop a customized tool that combines an existing tethered crawling tool with an instrument that detects corrosion damage or metal loss.

The unique combined tool—a first of its kind in the world—was developed to inspect two parallel 12-inch gas lines running under a navigable waterway and an international crossing in the U.S. previously considered “non-piggable,” or not possible to inspect with an ILI tool.

The crawling tool was outfitted with two technologies: 1) an eddy current array, which combines multiple units that rapidly inspect large areas of the pipe’s inner surface, and 2) bi-directional axial magnetic flux leakage, which magnetizes the steel then detects any magnetic field “leaks,” allowing the pipeline to be monitored for possible corrosion or metal loss.

The successful deployment of the tool has provided valuable data which is being used to make asset lifecycle decisions.

Using drones for aerial inspections

We continued to use magnetometry technology for aerial inspections of our GTM assets, inspecting 27 sites in 2025. The technology uses a portable magnetometer mounted to a drone. During aerial surveys, the magnetometer records magnetic field data, which is then processed to rapidly and precisely map subsurface attributes including metal objects and pipeline position. Magnetometry helps identify depth of cover changes and check whether ground movement has affected a pipeline segment, as it can measure small movements of the pipeline to within 2.5 cm (1 inch).

We can deploy the drone when and where it is needed, without advanced scheduling or service disruptions. This technology is especially useful for inspecting right-of-way conditions and ground stability after heavy rains and floods, when limited access and timeliness reduce our inspection options. We are also incorporating new learnings including identifying right-of-way constraints (like vegetation height and thick tree canopy) that can degrade data quality.

Improving crack detection with sound waves

In 2025, we ran our first deployment of a new crack detection tool designed specifically for gas systems. The tool, developed through a collaboration between Enbridge GTM and NDT Global, combines multiple state-of-the-art gas-coupled ultrasonic transducers to generate sound waves in the pipe to detect, characterize and size stress corrosion cracking and similar cracking threats. The tool leverages more than 20 years of experience acquired by NDT Global managing cracking with ultrasonic ILI tools designed for liquids systems.

This detection technology enables us to improve proactive identification of any features of concern within the pipeline while reducing unnecessary integrity digs and blowdowns—and the associated release of greenhouse gases—and improves our resource allocation to higher risk assets.