ROSEN has engaged in a major pipeline project in Ontario, Canada, using its customised solutions to improve operations.
The Enbridge Gas (EG) network in Ontario spans over 150,000km of pipeline, including 3700km of high-pressure transmission lines critical to energy delivery across the province. To safeguard these assets, EG has operated a transmission integrity management program (TIMP) for more than two decades.
This program involves rigorous assessment of over 30 potential threats, with internal and external corrosion, third-party interference, and geohazards ranking among the most significant.
EG Ontario employs a combination of deterministic and risk-based methodologies to prioritise pipelines for integrity verification through in-line inspection (ILI) or non-destructive examination (NDE).
While ILI remains the preferred method, certain pipelines present challenges that render traditional inspection tools ineffective, creating data gaps. In such cases, bespoke solutions are required.
One challenge involved two parallel nominal pipe size (NPS) 12 (DN300) pipelines, named A and B.
Installed in the 1940s and suspected of internal metal loss, and with no direct condition data available, EG relied on expert judgement and analogous asset performance to assess the risk.
The resulting evaluation highlighted risk levels beyond acceptable operational and reputational thresholds. Although replacement was considered, a thorough inspection was deemed necessary before committing to such a major intervention.
The pipelines, which run beneath a major river and are co-operated with another pipeline company, were not designed for conventional ILI.
Their construction features – thick-walled pipe, welded sleeves at girth welds, and around 85 heavy cast iron river weights – cause significant magnetic interference that hampers magnetic flux leakage (MFL) tool performance.
Ultrasonic inspection was also ruled out due to the elevation profile and the impracticality of removing couplant, which is essential to maintain gas quality.
To overcome these limitations, EG Ontario collaborated with inspection technology provider ROSEN to develop a customised inspection solution. Building on prior success with self-propelled MFL tools, ROSEN proposed a hybrid ILI system that combined axial MFL with a bespoke Eddy Current (EC) sensor module. This configuration was intended to mitigate magnetic interference and improve the detection of internal metal loss. Following a detailed technical evaluation, the project was launched in late 2023. The collaboration aimed to deliver a tailored inspection solution for these legacy assets by adapting and advancing existing ILI technologies.
Given the limitations of conventional tools, a flexible, self-propelled platform was selected to minimise operational complexity and risk. Axial MFL was chosen as the primary inspection method due to its compatibility with self-propelled systems and proven reliability. However, due to magnetic distortion from the cast iron river weights, a secondary inspection method was required. EC technology, previously used successfully in offshore applications with similar heavy-wall and interference challenges, was identified as a suitable complement.
While the MFL and crawler platforms were commercially available, ROSEN had to design a completely new EC module for this specific use case. The development process needed to accommodate mechanical and performance constraints while ensuring compliance with API 1163 standards.
A major design requirement was the ability for bi-directional movement – conventional EC systems are often built for single-direction use and vulnerable to damage when reversed. ROSEN addressed this by engineering a novel, yoke-mounted EC sensor array, 3D-printed using carbon fibre-reinforced composite. This allowed staggered sensor placement for full circumferential coverage, while maintaining structural integrity and compactness.
Once assembled, the EC module was integrated into the self-propelled system alongside the MFL component, creating a dual-technology inspection tool suited to the complex environment of Pipelines A and B.
To validate the tool’s readiness, an extensive testing regime was conducted. This included passage, friction, and pull tests to confirm mechanical reliability and measurement accuracy under realistic pipeline conditions. A purpose-built passage loop replicated the pipelines’ most restrictive features, through which the crawler navigated smoothly in all orientations. Friction testing confirmed stable operation on varied elevation profiles.
Pull testing used an 11-spool test line containing artificial metal loss and geometric anomalies. The EC module consistently detected and sized all anomalies within the defined range (1–9mm deep, 10–36mm in length/width). Additional testing simulated magnetic interference from the cast iron weights using a steel half-shell.
The EC system maintained signal integrity and sizing accuracy, demonstrating effective resistance to external interference – one of MFL’s known limitations.
The results confirmed the EC tool’s mechanical robustness and high measurement precision, proving it suitable for pipelines with both complex geometry and magnetic interference. The successful outcome validated the integration of EC and MFL technologies for a comprehensive assessment of the pipelines’ internal condition.
Following successful lab validation, the tool and crew were mobilised for field deployment in Ontario. Field operations were conducted safely and in accordance with all operational protocols. The self-propelled inspection vehicle completed runs through both pipelines in forward and reverse directions, collecting comprehensive data sets and ensuring full circumferential coverage, with redundancy in key areas.
Preliminary data quality checks confirmed the inspection met performance expectations for both MFL and EC systems. The data was deemed suitable for in-depth analysis, with sufficient resolution and fidelity to support asset integrity decisions.
The inspection of pipelines A and B posed significant technical challenges due to their age, unique construction, and environmental constraints. Through close collaboration, EG Ontario and ROSEN developed and deployed a novel ILI system that combined MFL and EC technologies on a self-propelled platform. The successful design, validation, and deployment of this tool demonstrate how innovative, tailored approaches can overcome the limitations of legacy infrastructure.
The high-quality data gathered now feeds directly into EG Ontario’s TIMP, supporting informed, risk-based decision-making and helping to maintain the long-term integrity of these critical assets.
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This feature also appears in the July edition of The Australian Pipeliner.