The American Petroleum Institute (API) on Tuesday reported a decrease of 6.195 million barrels of crude oil in U.S. inventories for the week ending Aug. 11.
Analysts expected a drop of 2.050 million barrels for this week.
The API reported a hike of 4.067 million barrels in the previous week.
Oil prices settled lower on Tuesday.
The West Texas Intermediate for September delivery dropped 1.52 dollars, or 1.84 percent, to settle at 80.99 U.S. dollars a barrel on the New York Mercantile Exchange.
