Brent crude futures rose 18 cents, or 0.2%, to $83.47 per barrel by 0452 GMT, while U.S. West Texas Intermediate (WTI) crude futures gained 4 cents to $77.62 a barrel.
Data from the American Petroleum Institute showed U.S. crude inventories fell by about 3.8 million barrels in the week ended March 3, according to market sources.
The drawdown defied forecasts for a 400,000 barrel rise in crude stocks from nine analysts polled by Reuters.
Traders were awaiting crude inventory data from the U.S. Energy Information Administration later on Wednesday, after the API data showed a decline in crude inventories for the first time after a 10-week build, she added.
Powell's comments propelled the U.S. dollar, which typically trades inversely with oil, to hit a three-month high against a basket of currencies.