Please provide links supporting your comment that Putin came to steal hydrocarbons in2012. Also, specify which hydrocarbons and from where.
Putin invaded in 2014 to seize the offshore hydrocarbons discovered in 2012, he did not invade in 2012 (it required some prep time).
That is primarily why he annexed Crimea - for its territorial waters, and their deposits.
Russia is a petro state, hugely dependent on its oil and gas industries - one of the most dependent on Earth. Putin personally gets a cut. His personal wealth was estimated at around $200 billion, before this failed gamble to steal the whole of the Ukraine, for his mafia family to exploit.
He has gone way beyond brass knuckle autocrat who has a few opponents killed or jailed, or mafia boss who has competitors killed (all of which he has also done). Now he has has unleashed mass killing and destruction on a scale that Europe has not seen since WWII, to slake his unholy thirst for wealth and power.
The war crimes investigations are well underway, documenting the deliberate and systematic way he had his forces attack civilians on a mass scale, and round up political opponents for torture (the real stuff, not waterboarding) and execute. Trenches filled with hundreds of civilian bodies, mobile crematoria working through the night.
Deliberately, as planned.
It is demonic.