Enbridge Launches MLO2 Open Season - Expansions on Seaway, Flanagan South, and Southern Access Extension
250,000 barrels per day of new Canadian egress on MLO2 includes Seaway, Flanagan South, and Southern Access Extension expansions
Enbridge Initiates Multiple Open Seasons - 250,000 bpd Pipeline Expansion from Western Canada to U.S. Gulf Coast/Midwest
On Friday, Enbridge launched open seasons on their Flanagan South, Seaway, and Southern Access Extension pipelines, offering a combined 250,000 barrels per day of new capacity with receipt points linked back to Western Canada. The move appears to be tied to the company’s Mainline Optimization 2 (MLO2) Project which will use the Dakota Access Pipeline to shift light crude off the Canadian mainline, freeing up capacity for heavier crude on Enbridge’s Mainline system to Flanagan, Illinois.
Shippers appear to have two downstream options for the new capacity: 200,000 bpd of expanded capacity on the Flanagan South and Seaway pipelines (green and blue lines below) for direct access to the Texas Gulf Coast, or 50,000 bpd on the Southern Access Extension (red line below) to Patoka, Illinois, where barrels can connect to ETCOP or other third-party pipelines for onward transport to the Midwest or Gulf. The timing is notable, as several competing projects are also vying for incremental Western Canadian volumes, including Trans Mountain’s drag-reducing agent expansion (up to 90,000 bpd) and the recently concluded South Bow/Bridger/Pony Express open seasons for up to 550,000 bpd of new capacity into Cushing with access to the Gulf Coast.
Seaway Expansion Sparks Questions on Future Cushing Takeaway Capacity
The open season language indicates MLO2 will include a capacity expansion on Seaway Pipeline as well. Seaway is a critical north-to-south crude route from Cushing, Oklahoma, to the Texas Gulf Coast and is a 50/50 joint venture between Enbridge and Enterprise Products. The system consists of two parallel 30-inch pipelines serving Freeport, Houston, Texas City, Port Arthur, and Nederland. The older line, built in the 1970s, has a listed capacity of just 300,000 barrels per day, while the newer line, built in the mid-2010s, carries 650,000 bpd (~950,000 bpd combined). However, post-COVID average flows have hovered closer to 750,000 bpd (see graph below). Nevertheless, the open season language signals that more capacity may be planned.
Notably, Enbridge’s proposed 200,000 bpd expansion from Flanagan to the Gulf Coast via Seaway, along with the recently concluded South Bow/Bridger/Pony Express open season, would both route incremental Western Canadian barrels through Cushing as a key waypoint. With one or both projects likely to be sanctioned, this raises important questions about future takeaway capacity out of Cushing. Additional infrastructure beyond the planned Seaway expansion may ultimately be required, depending on the final volumes sanctioned. We will discuss this topic further in our video update early this coming week.
Flow/Transaction Updates and New Assets Under Coverage
Plainview has over 300 assets with crude oil flow or transactional data on our platform and continues to add more each week. Data for existing assets under coverage are posted as soon as they become available. Below are the assets that were updated this week or newly added to coverage.





