Brent rose 30 cents to USD 48.43 a barrel by 0420 GMT after it finished up 44 cents on Friday, while US crude rose 32 cents to USD 45.86 a barrel after settling up 80 cents, buoyed by news that Russia was ready to meet OPEC, non-OPEC producers for consultations.
A report from Baker Hughes Inc. said the number of active rigs in the United States fell by 26 to 614 last week, the lowest in five years, helping ease concerns over the global crude oversupply that has depressed prices.
Traders said that a political risk premium has re-entered oil markets over Syria, where Russia and the United States are both carrying on bombing campaigns without coordination, triggering fears of unintentional clashes.
The International Monetary Fund is likely to revise downwards its estimates for global economic growth due to slower growth in emerging economies, IMF head Christine Lagarde said in a newspaper interview.
Concerns about a slowdown in the global economy, particularly key energy consumer China, combined with an oversupply have seen crude prices tumble more than 60 percent from last year's peaks above USD 100 a barrel.
A build in gasoline inventories following the end of the US summer driving season and falling refinery runs at the start of maintenance period offset crude drawdown, John Kilduff, founding partner at Again Capital said.
Industry group the American Petroleum Institute reported that US crude stockpiles fell 3.7 million barrels last week, with stocks at the Cushing, Oklahoma delivery point for US crude futures alone down almost 500,000 barrels.
Crude oil prices have plunged almost 60 percent since June 2014, when soaring global production started to clash with slowing demand. This includes losses of more than a quarter since June this year as a sharp slowdown in China has sparked concerns over the health of the world economy.
US West Texas Intermediate (WTI) crude futures CLc1 were trading at USD 46.70 per barrel at 0049 GMT, down 20 cents from their last settlement. Brent prices were little changed at USD 49.14 per barrel.
US crude futures rose after industry group the American Petroleum Institute (API) reported a 3.1 million-barrel crude drawdown last week, versus analyst expectations for a build. A surge in American gasoline prices was also supportive.
Crude prices fell on Monday with the onset of lower demand autumn trading and as weak economic data out of China and soft gasoline prices RBc1 pressured the market.
The US oil rig count fell by 10 to 652 last week, the second straight monthly drop, and the International Energy Agency said on Friday that ongoing production cuts would lead to a rebalancing of the market by next year.
US crude futures CLc1 were trading at USD 44.86 per barrel at 0215 GMT, up 23 cents from their last settlement, pushed by a slight fall in drilling activity.
Asian shares gained after upbeat German economic data powered rising US and European markets, and traders said the more upbeat sentiment in Asia had flowed through to oil markets.
Japan's economy shrank an annualised 1.2 percent in April-June, revised GDP data showed on Tuesday, despite ongoing government and central bank measures to support growth.
US benchmark West Texas Intermediate for October delivery fell 45 cents to USD 45.80 while Brent crude for October slipped 38 cents to USD 50.12 in late-morning trade.
Brent and US crude finished around 8 percent lower on Tuesday to end a 25-percent three-session surge, the largest three-day gain since 1990.
US crude, also known as West Texas Intermediate, climbed 27.5 percent by the end of the previous session after three days of gains, the largest three-day increase in dollar terms since February 2011 and the biggest percentage increase since August 1990.
World stock markets rallied on Thursday as Chinese shares recovered on hopes that government measures to stimulate the economy would pay off, while the dollar also rallied as risk aversion eased.
China cut interest rates on Tuesday and lowered the reserves banks must hold in its latest move to calm fears about a severe economic slowdown in a country whose major equities index, the Shanghai Composite Index, is now 43% below the June peak for the year.
Futures earlier fell to almost USD 40 a barrel on Thursday, their lowest since the global financial crisis of 2009, as supplies rose in North America and the Middle East, filling stockpiles to record levels.