US West Texas Intermediate (WTI) crude was down 30 cents at $47.77 a barrel.
Brent for November settlement added 42 cents to $54.69 on the London-based ICE Futures Europe exchange.
Irma, the second major storm in the USA region in a fortnight, made landfall in Florida on Sunday as a Category 4 hurricane, knocking out power to almost 5.8 million homes and businesses in the state. It gradually lost strength and weakened to a tropical storm by Monday morning as it headed toward Georgia.
The report from OPEC also highlighted that production outside the group fell in August, driven by disruptions in the US after Hurricane Harvey rampaged through the oil producing regions in Texas and Louisiana. Refinery utilization rates fell by 2 percentage points to 77.7 percent, the lowest rate since 2008.
The IEA said that commercial oil inventories in the Organization for Economic Cooperation and Development, or OECD, stayed flat in July month-on-month, at 3.016 billion barrels, about 190 million barrels above their five-year average.
As well as the supply cut, a rise in demand of close to 2 million barrels a day in the second half of the year relative to the first will help get rid of excess oil in storage. USA supplies increased 5.9 million barrels in the past week, the Energy Information Administration reported Wednesday morning. The EIA's next weekly report is due on Wednesday.
Oil prices were bolstered today following figures that showed the global oil surplus declined as European and United States demand rose more than expected in the second quarter. That is "because Texas has twice the oil consumption per capita of Florida given the significant concentration of refining and petrochemical capacity on the U.S. Gulf Coast", they said.
Ministers are now discussing extending the pact by at least three months. World Oil Supply Non-OPEC oil supply is expected to grow by 0.78 mb/d in 2017, unchanged from the last month due to offsetting revisions in Kazakhstan and USA supply.