Ukraine is loaded with gas and oil reserves as well as its Black Sea neighbors. Invasion of eastern Ukraine and the seizure of the Crimea prevent their exploration, expansion, and use of those shale oil finds which would diminish dependency on Russia.
This is absolutely right:
Metals and the invasion: Ukraine aims for critical minerals after the war. https://www.spglobal.com/marketintelligence/en/news-insights/latest-news-headlines/metals-and-the-invasion-ukraine-aims-for-critical-minerals-after-the-war-74205684
Ukraine has Europe’s third largest shale gas reserves, at 1.2 trillion cubic meters (tcm)
https://en.wikipedia.org/wiki/Natural_gas_in_Ukraine
and thank you for the link to the 10 year old article which is largely correct.