An industry source who also tracks exports said October shipments were so far below 1 million bpd.
Benchmark Brent crude jumped by $1.13 a barrel to a high of $85.04 before easing back to $84.56, up 65 cents, by 1330 GMT.
Brent crude futures fell $1.91, or 2.3 percent, to settle at $83.09 a barrel.
OPEC cut its forecast for growth in non-OPEC oil supply in 2019 by 30,000 bpd to 2.12 million bpd.
Oil prices have extended a rally on expectations the sanctions will test the Organization of the Petroleum Exporting Countries and other producers.
“At the heart of the price malaise are concerns that oil demand will be adversely impacted by a myriad of downside risks facing the global economy”.
The global oil demand outlook of OPEC for 2019 was lowered by 50,000 barrels a day to 1.36 mln barrels daily.
Crude futures steadied late in the session on Friday, following the stock market slightly higher after earlier swinging lower on a weakening oil demand outlook.
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.
The U.S. President has reaffirmed economic sanctions on Iran during his recent speech at the United Nation’s General Assembly.
The landmark nuclear deal, signed during the Barack Obama regime, was concluded between Iran and six world powers which include, U.S., Russia, U.K., China, France, and Germany, that lifted sanctions on Iran but place strict limits on its nuclear program for 12 years.
“According to secondary sources, total OPEC-15 crude oil production averaged 32.76 mb/d in September, an increase of 132 tb/d over the previous month”. OPEC has been under the hit list from the USA for declining the increased outcome to answer rising oil prices.
Almost 40 percent of daily crude oil production and more than one-third of natural gas output was lost from offshore U.S. Gulf of Mexico wells on Wednesday because of platform evacuations and shut-ins ahead of Hurricane Michael.
Early in the session, crude rose as global equities were set for their biggest daily gain in almost a month.
“So there is real commitment in the selling … adding to the idea that we are seeing a turn in the market”, he said.
Worries about crude supply from the Middle East have given prices some support.