Benchmark U.S. crude for February delivery shed 29 cents to $98.75 per barrel in electronic trading on the New York Mercantile Exchange.
Brent crude for February delivery, a benchmark used to price international crudes used by many U.S. refiners, shed 29 cents to $110 in London.
Meanwhile, natural gas held steady at a 29-month high of $4.46 per thousand cubic feet on Nymex. It added 5 percent a day earlier after the U.S. government reported a huge draw in supplies due to recent cold weather.
The Energy Department said Thursday that natural gas supplies dropped by 285 billion cubic feet last week and are 261 billion cubic feet below the five-year average.
Oil prices rose despite the U.S. Federal Reserve's decision to ease its stimulus, which analysts believe will lead to lower oil prices.
The Fed's action is expected to increase the value of the dollar compared with other currencies. That makes commodities such as oil, which are priced in dollars, more expensive and less attractive.
However, the Fed's decision also was seen by financial markets as a vote of confidence that the American economy is strengthening. That might fuel expectations for higher energy demand.
In other energy futures trading on Nymex:
— Wholesale gasoline edged up 0.8 cents to $2.748 a gallon.
— Heating oil shed 0.3 cents to $3.022 per gallon.