Damage from the explosion was limited to the refinery's boiler, which had been shut down temporarily as part of a turnaround operation. Process units and other areas were not affected.
Operations at the refinery, which employs about 270 people, resumed Saturday.
CVR's refining business also includes a refinery in Coffeyville, Kan. The two facilities can handle 185,000 barrels of oil a day.
CVR acquired the Wynnewood refinery with its $525 million purchase of Gary-Williams Energy Corp. in December before the majority of the Texas-based company was purchased by activist investor Carl Icahn. The company unsuccessfully tried to find another buyer during the summer.
The Associated Press