Brent crude futures fell 44 cents, or 0.5%, to $94.92 a barrel by 0454 GMT, while U.S. West Texas Intermediate (WTI) crude futures fell 53 cents, or 0.6%, to $88.38 a barrel.
CMC Markets analyst Tina Teng said despite tight supply in the physical markets, China's slowdown in demand has a major impact on the oil futures markets.
In another bearish sign, API data showed gasoline inventories rose by about 2.6 million barrels, against analysts' forecasts for a 1.1 million drawdown.
Meanwhile, supply concerns remain as a European Union ban on Russian crude looms and the Organization of the Petroleum Exporting Countries and allies, or OPEC+, cuts output.
The EU will ban Russian crude imports by Dec. 5 and Russian oil products by Feb. 5, in retaliation to Russia's invasion of Ukraine.