Oil prices went down on Wednesday as official data showed that U.S. crude inventories rose unexpectedly last week.
The West Texas Intermediate for September delivery decreased $2.03 to settle at $65.01 a barrel on the New York Mercantile Exchange, while Brent crude for October delivery fell $1.70 to close at $70.76 a barrel on the London ICE Futures Exchange.
The Energy Information Administration said in its weekly report on Wednesday that US commercial crude inventories rose by 6.8 million barrels in the week through Aug. 10, way higher than market estimates of a decrease of 2.5-million barrels.
A report earlier said that inventories at the closely-watched US delivery hub at Cushing, Oklahoma rose by 1.7 million barrels in the week through August 10.
The surprise build of U.S. inventories weighed on the market on Wednesday, with both WTI and Brent oil prices dropping over 2 percent.