Putin needs higher oil prices a lot more than he needs either Iran or Venezuela (or Cuba, for that matter).

You don't understand Russian mentality. The closer ally you are, the more likely you'll find yourself being defenestrated.

And this is why Russian states seem to always end up collapsing in on themselves...

If I fall asleep and wake up in a hundred years and am asked what is happening in Russia, I will answer: drinking and stealing.