Oil and gas exports have been a mainstay of Russian government revenue for a long time. It seems that customers are hesitant to place orders for crude subsequent to the recent sanctions against Rosneft and Ukoil. Jo Blogs (link below) observes that to maintain production of crude Russia has started loading tankers and sailing them away with no customer or destination port. However many 'shadow tankers' Russia has, it will not be long before all land storage capacity and tanker storage capacity will be consumed, at which point Russian crude production will need to be reduced.
Of course, all the crude stored in Russian tankers on the high seas does not give the Russian government any revenue. I can imagine some buyers exploiting the situation to buy Russian crude at a massive discount to the world price. If Russia was getting, say, 50 USD per barrel on average so far in 2025 for 4 million barrels a day, anything becomes possible when Russia has nowhere to store its production. At that point Russia may have to sell at almost any price the buyer offers.
My 'back of envelop' calculation:
4 million bpd @ 50 USD per barrel = revenue of 200 million USD per day or around 75 billion USD per year.
2(?) million bpd @ 20 USD per barrel = revenue of 40(?) million USD per day or around 15(?) billion USD per year..
The war should rapidly become unaffordable for Russia. Yippee!
And you have people like Putin and Trump thinking they can force a 'peace' deal onto Ukraine just as things look to get far, far worse for Russian finances and GDP in the very near future!
IMO Zelensky should politely study the peace proposal at great length to humour Trump. The longer he studies it, the better.