US benchmark West Texas Intermediate (WTI) for March delivery rallied USD 1.84 to USD 50.68 a barrel compared with Wednesday's close.
Brent North Sea crude for March leapt USD 2.52 to USD 57.18 a barrel in late afternoon trade in London.
"Crude oil prices rebounded ... Supported by a softer US dollar," said Sucden analyst Myrto Sokou.
The weaker greenback makes dollar-denominated crude cheaper for buyers using stronger currencies. In turn, that tends to stimulate demand and price levels.
More From This Section
"There is some optimism in the market at the moment, but the fundamentals have not changed," Michael McCarthy, chief market strategist at CMC Markets in Sydney, told AFP.
"The increased US stockpiles adds to the worry about ample global supply, which is the main cause for the current bearish market," he added.
The US Department of Energy reported on Wednesday that commercial crude reserves rose 4.9 million barrels in the week ending February 6.
Stockpiles were "at the highest level for this time of year in at least the last 80 years", the agency added.
However, they have recovered slightly in recent weeks as the number of drilling rigs has fallen and oil companies have trimmed some investment.