Iran reported September production of 3.76 million barrels a day, a month-over-month drop of 51,000 barrels, and Venezuela reported a drop of 14,000 barrels to a total of 1.43 million barrels a day.
U.S. crude futures were trading down more than 2% at US$73.20 per barrel Wednesday morning, reflecting the declining importance of Gulf of Mexico output that has resulted from the growth of production from the nation's onshore shale fields.
Brent crude settled up 17 cents a barrel at $80.43, after dropping 3.4 percent on Thursday.
In 2019, forecasters such as the International Energy Agency say emerging-market crises and trade disputes could dent global demand while rising production from outside the Organization of the Petroleum Exporting Countries adds to supply.
Meanwhile, EIA expected West Texas Intermediate (WTI) crude oil prices will average about 6 dollars a barrel, lower than Brent prices in 2018 and in 2019.
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"The weaker outlook has gotten a raised profile in the market, but there's potential for a real supply crunch toward the end of this year", said John Kilduff, a partner at Again Capital Management in NY.
Both benchmarks were headed for their first weekly drop in five weeks, pressured by a big rise in USA inventories and fading concerns about shrinking global supplies due to looming US sanctions on Iran's oil exports. According to meteorologists, the hurricane is being fed by warmer sea surface temperatures, which could lead to waves of between 15 and 20 feet-enough to disrupt oil and gas production in the Gulf.
Michael has strengthened into an "extremely dangerous" Category 4 hurricane, according to the latest advisory from the U.S. National Hurricane Center.
In the U.S. Gulf of Mexico, producers were checking production platforms and beginning to return crews to more than 90 offshore facilities evacuated this week as Hurricane Michael moved through the Gulf.
Iranian crude oil exports will be much reduced, and if they stay above 1 million bpd, "we'll be much surprised", Taylor said.
U.S. crude stockpiles rose more than expected last week, while petrol inventories increased and distillate stocks drew, industry group the American Petroleum Institute said on Wednesday. Supply data from the Energy Information Administration will be released Thursday.