Analysts said the report also indicated OPEC's production-cutting deal with non-OPEC is helping to curb a supply glut.
Meanwhile, the market continued to assess Hurricane Irma's effect, as many refineries are restarting right now and lifted demand for American crude.
The OPEC's report also said the two hurricanes that had hit the United States would influence the demand side.
The impact of Hurricane Harvey has been particularly damaging to the energy centers of Texas and Louisiana, bringing to mind the destructive impacts of past storms, in particularly Hurricane Katrina in 2005, said the report.
The West Texas Intermediate for October delivery ticked up 0.16 U.S. dollar to settle at 48.23 dollars a barrel on the New York Mercantile Exchange, while Brent crude for November delivery rose 0.43 dollar to close at 54.27 dollars a barrel on the London ICE Futures Exchange.