Syncrude says it is looking into what caused an early-morning fire at the company's Mildred Lake Base plant, just north of Fort McMurray, Saturday.
Syncrude spokesman Will Gibson said the fire was extinguished quickly and no injuries were reported.
"The people who work on our sites, we want them to go home at the end of the day," he said.
Gibson said they did not evacuate the facility, which deals mostly with sulphur, but they did turn contractors away from the plant Saturday, both for safety reasons and to preserve the area for investigation.
"We will be thoroughly investigating this incident and will release more information when available," said Gibson, who doesn't know when contractors will be allowed back on site.
He said it was too early to tell if the incident will affect production at the plant.