
WTI climbed 3.3% to US$82.12 and Brent also piled on 3.3% to US$87.94 ahead of a meeting of the group this week in Vienna.
The jump comes after both main contracts suffered hefty losses in recent months on demand fears caused by an expected recession in major economies.
The reduction in production – which delegates to Opec said had not been finalised – would be the biggest since the pandemic began, when crude prices collapsed.
Officials will meet on Wednesday.
Suvro Sarkar, an energy analyst at DBS Bank, expected more gains were likely.
“It’s only going to be a matter of time before oil returns to US$100 a barrel, especially with supplies set to tighten toward the end of the year,” he said.