Oil prices nudged higher in tepid Asian trading on Thursday, supported by a weaker dollar and optimism that crude producers would abide by an agreement to curb output to prop up markets.
But gains were capped by an unexpected rise in U.S. crude inventories last week and as Libya said it expected to boost output over the next few months.
Brent futures for February delivery climbed 18 cents to $54.64 a barrel as of 0423 GMT, having previously finished 89 cents lower.
U.S. West Texas Intermediate crude rose 15 cents to $52.64 a barrel, after closing the previous session down 81 cents.
The dollar index, which tracks the greenback against a basket of six rival currencies, slipped as investors took profits after its rise to a 14-year peak of 103.65 earlier this week.
A weaker dollar makes greenback-denominated commodities including oil cheaper for holders of other currencies.
"We're pretty close to the closing level - it'll be interesting to see if the upward momentum is maintained as the Europe and U.S. sessions open up," said Ric Spooner, chief market analyst at CMC Markets in Sydney.