St. Paul Park Refining Co. is operating at lower capacity after fire broke out inside the refinery's larger crude distillation unit Sunday morning.
The Star Tribune reports repairs to the damaged unit are estimated to cost about $10 million and will take three to four weeks to complete.
Investigators are looking into the cause of the fire. No one was injured.
Formerly known as the Marathon Oil refinery, St. Paul Park Refining Co. was purchased three years ago by Northern Tier Energy, which supplies gas mainly to Super America gas stations.
The company says the refinery should be producing 40,000 barrels per day by early October. Output is expected to more than double by mid-October.