Enbridge Launches Pipeline Replacement


Canadian energy giant Enbridge Inc. has begun construction on a $6.5 billion project that will replace more than 1,000 miles of its Line 3, a crude oil pipeline that the company says is at risk for corrosion due to failures in its protective coating.

The first segment to be built in the Canadian section of the project will comprise about a quarter of the total length, starting at the line’s origin in Hardisty, Alberta. The pipeline carries crude from the Alberta oil sands to Wisconsin, via Saskatchewan, Manitoba, a small section of North Dakota and Minnesota.

In replacing the original Line 3, which was put into service in 1968, Enbridge will also be increasing the pipeline’s capacity; the original 34-inch line will be replaced with a new 36-inch line that’s expected to nearly double the volume of oil transported daily.

Line 3 was originally built to transport 760,000 barrels per day of light, medium and heavy crudes. In 2010, Enbridge voluntarily limited the line to 390,000 barrels per day of light crude only. The new pipeline is expected to initially transport 760,000 barrels per day again. Its full design capacity will be 844,000 barrels per day.

Tapecoat Concerns

According to Enbridge officials, Line 3, unlike a number of the company’s other pipelines, was protected with a tapecoat, which has since been found to have disbonded from the pipeline steel. Enbridge says the coating failure has sped corrosion rates, causing concerns over deterioration in the line.

Line 3 map

Enbridge is awaiting approvals from the state of Minnesota, which is the final government needed to issue permits for the pipeline project.

According to permit application documentation, Enbridge plans to construct the new pipeline of high-strength GX-70 steel, with a nominal wall thickness of 0.515 inches (with stretches made of thicker pipeline when necessary, such as segments installed via road bore or horizontal directional drilling).

The mainline will be coated with 14 mils of epoxy bonding, and stretches installed via trenchless methods will be coated with 50 mils.

Minnesota Routing Questions

The only major deviation Enbridge plans from the current pipeline route will occur in Minnesota and Wisconsin, where the company plans to reroute the line along existing pipeline and electric transmission line rights-of-way.

Enbridge requires two approvals from the Minnesota Public Utilities Commission in order to move forward with that phase of the pipeline plan: a certificate of need and a route permit. The state is currently in the process of reviewing public comments on a draft environmental impact statement for the project, and expects to issue final rulings on the two permits by next spring.

Increasing Costs

Enbridge addressed the project at the time of its quarterly earnings report Thursday (Aug. 3). The company noted that its new cost estimate for the overall project, $6.52 billion, represents an increase of about 9 percent over previous predictions. The company said delays in regulatory approval and routing changes are to blame for the cost increases.

According to Enbridge, the Line 3 replacement is the single largest project in the company’s history.


Tagged categories: Infrastructure; NA; North America; Oil and Gas; Pipeline; Program/Project Management

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