But soaring United States crude output, which hit a record 11.6 million barrels per day (bpd) last week, kept a lid on prices. It makes the United States the world's biggest producer of crude.
Crude stocks moved back above their five-year average levels in October. Unexpected waivers for buyers of Iranian crude have blunted the impact of US sanctions.
Futures tumbled 1.6 per cent Thursday, extending a decline from the October high to more than 20 per cent, meeting the common definition of a bear market. The EIA expects output to break through 12 million bpd by mid-2019, largely thanks to a surge in shale oil production.
Front-month Brent crude oil futures were down 6 cents at $72.01 a barrel.
Crude output hit 11.6 million bpd, a weekly record, though weekly figures can be volatile.
Commenting on this data, "Once again, the US has shown that when it is economic to do so, it can increase production at a greater pace than Saudi Arabia".
On Monday, as part of the Trump administration's "maximum pressure campaign" to get Iran to change its behavior, the US reimposed oil and banking sanctions on Iran that were lifted under the 2015 nuclear deal.
"We also saw demand from China's independent refineries rise", it added.
Preventing oil prices from rising any further has been a relentless rise in USA crude output, which hit a record 11.6 million bpd in the week ending November 2, according to Energy Information Administration (EIA) data released on Wednesday.
Saudi-led oil cartel and its allies, including Russian Federation, decided in June to relax output curbs in place since 2017, after pressure from United States (U.S.) President Donald Trump to reduce oil prices and make up for supply losses from Iran.
With output overall rising, supply is ample despite the Iran sanctions now in place, prompting rumblings within the Middle East dominated Organisation of the Petroleum Exporting Countries (OPEC) that renewed supply cuts may be needed next year to prevent a glut.
"Saudi Arabia and Russian Federation have increased production, and prices have come down $15 a barrel", Hossein Kazempour Ardebili, Iran's representative to OPEC, said in an interview.