West Texas Intermediate futures for October delivery advanced to $39.74 (+2.95%), while Brent crude rebounded to $44.42 (+2.97%). The U.S. Energy Information Administration reported Wednesday that the country's crude inventories unexpectedly fell by 5.5 million barrels in the week ending August 21, suggesting strong demand. U.S. crude production declined by 11,000 barrels a day in the same week, maintaining output above 9.3 million barrels, which is still close to a decades-high production level. Meanwhile inventories of gasoline rose by 1.7 million barrels, reminding of global glut issues.

Some analysts say that gains generated by the EIA data might be short-lived, because the bearish momentum can't be underestimated.

Recovery in stocks supported oil as well.