Exxon and Chevron are earning billions and benefiting from the new tax law, but profits are falling short of expectations that were based on rising oil prices.
The shares of both companies fell in afternoon trading Friday.
Both U.S. oil giants were expected to get a boost from crude prices, which rose sharply in the fourth quarter.
Exxon's production fell, however, by 3 percent from a year earlier, to about 4 million barrels of oil a day.
"This company just cannot get production growth going," said Brian Youngberg, an analyst with Edward Jones . "They talk about all these (new) projects, but they're always in the future. People...