Imperial Oil (TSE:IMO) said that bitumen production has resumed at its Kearl oil sands mine in northern Alberta after shutting down early last month due to a mechanical problem with the plant's ore crusher unit.
It confirmed that production has returned to "pre-shutdown" levels.
Canada's largest petroleum refiner did not provide any information on how much production was lost during the period. It announced the shutdown of its Kearl operations on November 11.
Kearl, which started bitumen production in April 2013, was producing an average of 92,000 barrels per day in the third quarter, excluding the impact of a planned 14-day turnaround in late September.
The operations had been designed to reach a production rate of 110,000 barrels per day, but they haven't reached that level since start-up.
Kearl sits about 70 km north of Fort McMurray, and is a joint venture between Imperial and its parent, Exxon Mobil (NYSE:XOM).
Shares of Imperial climbed 2.4 percent to C$53.02 as of 11:30am ET on Wednesday.