Refining margins "decreased significantly" both in the U.S. and overseas compared with the third quarter, Chevron said.
The company said oil for refining in the U.S. declined from the third quarter mostly due to the continued shutdown of a crude oil unit in Richmond, Calif. The company has said it expects the unit to be working early this year.
Before Thursday's update, shares of Chevron rose 93 cents in regular trading to close at $110.47. In extended trading, they were up another 74 cents to $111.21.