European oil sanctions are due to kick in on December 5. The idea is to reduce oil revenues for Russia given its war in Ukraine.

Andrey Rudakov | Bloomberg | Getty Images

Upcoming sanctions on Russian oil are set to be “really disruptive” for energy markets if European nations fail to set a cap on prices, analysts warned.

The 27 countries of the European Union agreed in June to ban the purchase of Russian crude oil from Dec. 5. In practical terms, the EU — together with the United States, Japan, Canada and the U.K. — want to drastically cut Russia’s oil revenues in a bid to drain the Kremlin’s war chest following its