Oil fell below $100 (£84.52) per barrel on Wednesday as the chief executive of energy giant Shell (SHEL.L) warned that Europe faces a "really tough" winter as energy costs soar.
Ben van Beurden said the bloc could be forced to "ration" its energy consumption in the worst case scenario if Russian president Vladimir Putin turns the tabs off.
"It will be a really tough winter in Europe. We will all face very significant escalation in energy prices," he told the Aurora Spring conference in Oxford.
The CEO last month warned that the world faces an "ever-tighter market" and a "turbulent period" because OPEC has less spare capacity than assumed.
Prices slumped to their lowest level since the early days of Russia's invasion of Ukraine as concerns about soaring inflation and an economic downturn weigh.
It comes as the International Energy Agency (IEA) warned earlier this week that the worst of the energy crisis is yet to come.
IEA executive director Fatih Birol said countries were experiencing the first global energy crisis, warning "We might not have seen the worst of it yet".
The oil market faces a tough period ahead as demand is poised to tick up next year and worries about supply persist following the Ukraine war. Rising coronavirus infections in China also weighs on prices.
On Tuesday, the OPEC forecast that world oil demand will tick up in 2023, but at a slightly slower rate than this year – if there is no escalation in Russia's war in Ukraine.
The cartel expects consumption to be supported as countries get better at containing the spread of COVID infections and still-robust global economic growth.
OPEC said demand will rise by 2.7 million barrels per day in next year. This year's growth forecast was left unchanged at 3.36 million bpd.
"In 2023 expectations for healthy global economic growth amidst improvements in geopolitical developments, combined with expected improvements in the containment of COVID-19 in China, are expected to boost consumption of oil,"
Watch: Why are gas prices rising?