Syncrude's Mildred Lake oilsands facility, which was shut down after an explosion and fire on March 14, has resumed shipments of upgraded synthetic crude oil.
One worker was seriously injured in the incident, which forced the facility to shut down.
Since then, crews have repaired damage and done maintenance work on the facility.
"Over the weekend, Syncrude completed the necessary repairs and start-up activities to begin shipping product by pipeline," Suncor, the majority owner of Syncrude, said in a news release Monday.
Shipments are currently at 140,000 barrels per day. Shipments are expected to ramp up as additional units complete turnaround activities, Suncor said.
Production is expected to return to full rates in June.
An initial investigation of the incident found a failure on a pipeline near one of the hydrotreating units caused treated naphtha — a highly flammable hydrocarbon mixture — to leak, triggering the fire, which burned for nearly two days before it was extinguished.
The Mildred Lake upgrader is located 40 kilometres north of Fort McMurray.