Was curious, so I did a 30 second search:
"The US Geological Survey estimates that onshore northeast Greenland (including ice-covered areas) contains around 31 billion barrels of oil-equivalent in hydrocarbons – similar to the US’s entire volume of proven crude oil reserves."
Source: https://theconversation.com/greenland-is-rich-in-natural-res...
Another 30 second search would show you that their oil is not readily available and is unproven. Otherwise Denmark would already be an even wealthier petrostate like Norway.
Also, Idk what that source is but the US has way more barrels than that. Proven reserves mean that’s what’s been proven via drilling, not speculative (which is what the Greenland barrels are). There is a lot more “unproven” oil out there but it doesn’t make for a sensationalist statement that fools readers.