Mitigation

Internal Protection

Not surprisingly, a pipeline's susceptibility to internal corrosion is largely determined by the nature of the products it carries. Although the liquids transported by Enbridge are not particularly corrosive, Enbridge routinely analyses the chemical make-up of these liquids and, if corrosion elements are present, anti-corrosive chemical treatments are injected into the pipeline.

Internal corrosion can also occur when water settles out of crude oil in segments of the line that are not under continuous flow. To minimize this effect, Enbridge employs corrosion inhibition chemicals and periodic flushing and/or internal cleaning of the pipeline using tight fitting scraping tools that move inside the pipe and remove water and sediment from the line.

In-Field Maintenance

In-Line Inspections provide the data that Enbridge needs to be proactive in dealing with defects. Once the company knows that a given section of pipeline could be subject to corrosion, cracks or other problems, it goes in for a first-hand look. This means excavating the affected sections of pipe for closer examination and making any needed repairs. Pipe replacement is rarely necessary. When further measurements and calculations indicate that a repair is necessary, the most common solution is to install a steel band - or repair sleeve - around the pipe to ensure the full pressure strength of the line in maintained. Before the site is backfilled, the pipe receives a new layer of protective coating.

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