London Brent crude was also up 10 cents at $45.92 a barrel. Oil prices lost 79 cents on Thursday, falling from Wednesday's $48.65 three-week high on hefty US oil inventories heading into the spring and a softer natural gas market.
"We saw prices rise a day or two ago on news of Opec's bullish outlook on demand. Now the market is focused on stocks in the United States, which have so far been able to meet demand," said Daniel Hyenas at ANZ Bank in Melbourne.
But Opec, which controls about 40 percent of global oil exports, has warned that a slide in prices or a big build in inventories could prompt swift action to stem output, possibly eating into stocks just as the summer driving season kicks in.
Producers are leaning toward cutting output at their March 16 meeting to defend prices against a second-quarter stock build, Opec's secretary general said this week.
Members will be looking for clues in US weekly stockpile data, which this week showed crude inventories in the world's largest energy consumer 8.5 percent higher than last year and gasoline supplies up 7.4 percent at the highest level since 1999.
BULLISH OUTLOOKS:
Analysts said bullish outlooks for oil demand this year from Opec and the International Energy Agency, the industrialised world's advisor, were helping keep prices at the upper end of the $45 to $50 range that they have traded in since January.
Global demand has climbed much faster than most analysts expected over the past two years, helping drive oil to a record high $55.67 last October. While that surge caught most observers on the hop, producers and consumers have adjusted quickly to levels that would have appeared astronomical just a few years ago.
On Thursday, the United Arab Emirates' Oil Minister Mohamed al-Hail said current oil prices, within reach of $50 a barrel, were "reasonable", while others in Opec have expressed a readiness to defend a higher price floor of $40 a barrel.
The key Gulf Opec producer plans to increase its oil stockpiles to meet any supply crunch on world markets. Continued growth in Asia and the United States is also supporting the view that higher fuel costs are not causing as big a dent in economies as once feared.
"I think the world can live with $45 oil," said Jeffrey Immolate, Chief Executive Officer of diversified manufacturer GE, the world's largest publicly traded company.