West Texas Intermediate futures for November delivery climbed to $48.08 (+0.56%), while Brent crude advanced to $51.67 (+0.66%) as remarks by Abdalla Salem El-Badri, secretary-general of the Organization of the Petroleum Exporting Countries, outweighed rising stockpiles in the U.S.

El-Badri said that global oil demand is estimated to increase by 1.5 million barrels per day in 2015, beating the initial projection. Demand is expected to be higher next year too. "In 2016, improvement in global economic activities is anticipated to support world oil demand to grow by 1.3 million barrels per day," he said.

The Energy Information Administration reported on Wednesday that U.S. crude oil stockpiles rose by 3.1 million barrels to 461.0 million barrels in the week ended Oct. 2. US production unexpectedly rose by 76,000 barrels per day. Meanwhile refining capacity utilization fell by 2.3% to 87.5%.

Data from the Custom Administration of Iran showed that in October the country sold only 720,000 barrels per day to its four major Asian clients China, India, Japan and South Korea, while Turkey bought 110,000 barrels per day.