Market Snapshot: Impacts of Enbridge’s BC Pipeline rupture on natural gas flows

Release date: 2019-01-23

On 9 October 2018, a section on Enbridge’s T-South natural gas transmission pipeline (BC Pipeline or Westcoast system) ruptured near Prince George, B.C.Footnote 1 BC Pipeline supplies natural gas from northeast B.C. to B.C.’s Lower Mainland and the U.S. Pacific Northwest (Figure 1). As a result, daily natural gas deliveries to points south of Prince George decreased 90%, from 1 290 million cubic feet (MMcf) on October 8 to 129 MMcf on October 10 (Figure 2, left-hand side).Footnote 2 In response, more natural gas flowed along FortisBC’s Southern Crossing pipeline (Figure 2, right-hand side). Gas flows on Southern Crossing approximately doubled after the BC Pipeline rupture, though these volumes were too small to replace the significant decreases resulting from the rupture.

Figure 1: Map of pipelines and points related to the rupture

Source and Description

Source: NEB

Description: The map shows Enbridge’s BC Pipeline, FortisBC’s Southern Crossing pipeline and other relevant points.

Figure 2: Daily natural gas receipts and deliveries to the B.C. Lower Mainland from BC Pipeline and Southern Crossing pipeline (August to December 2018)

Source and Description

Source: Enbridge

Description: This figure shows daily natural gas volumes flowing in the BC Pipeline before and after a rupture that reduced natural gas flows. The volumes shown are the deliveries on the BC Pipeline south of the Prince George rupture and the gas that the BC Pipeline received from the Southern Crossing pipeline.

  • On October 1, the volume of natural gas delivered south of Prince George was 1 433 million cubic feet
    • The day before the rupture (October 8), 1 290 million cubic feet was delivered
    • The day of the rupture (October 9), 937 million cubic feet was delivered
    • The day after the rupture (October 10), 129 million cubic feet was delivered
  • On December 1, the delivered volume was 1 179 million cubic feet
  • On October 1, the volume received from the Southern Crossing Pipeline was 33 million cubic feet
    • The day before the rupture (October 8), 0 million cubic feet was received
    • The day of the rupture (October 9), 49 million cubic feet was received
    • The day after the rupture (October 10), 107 million cubic feet was received
  • On December 1, the volume received was 30 million cubic feet

The affected section of the BC Pipeline near Prince George (Figure 1) has two pipelines – a 30 inch mainline and a 36 inch loop.Footnote 3 Both lines were shut down when the 36 inch pipe ruptured. Following an evaluation of the line, the National Energy Board (NEB) allowed Enbridge to resume flowing gas on the 30 inch mainline on October 10. Over the course of several weeks, deliveries significantly increased after additional assessments supported safely increasing pressure on certain pipeline segments. By December, volumes increased to approximately 1 400 MMcf per day (December volumes typically average around 1 700 MMcf per day). The majority of the 36 inch loop is flowing gas under restricted pressure, and it will return to maximum operating pressure after the NEB concludes it is safe to do so.

The Southern Crossing pipeline carries a relatively small amount of natural gas into southern British Columbia from NGTL’s Alberta System. It can transport about 100 MMcf per day of natural gas westbound through southern B.C. In addition, FortisBC dispatched trucks carrying compressed natural gas into the Lower Mainland during December. Restrictions originally placed on industrial and commercial consumers to curtail natural gas consumption were lifted. However, according to FortisBC, until Enbridge’s transmission pipeline is operating at full pressure, customers should still be mindful of their energy use.

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