Yes, but shouldn't the countries get at least a tiny bit of cash from the USA for the concessions?
Which, in a simplified way, could additionallly also symbolize some of the costs (wages, machines, transport) of oil exploration.
Yes, of course, as I wrote - 20% of the extracted oil remains to the countries on whose land it was extracted.
I do not have exact information on the terms of all concessions, but as far as I was able to study this issue, the proportion of 80% to 20% can be taken as average and generally accepted at that time.
Therefore, Venezuela and others are left with 20% of their oil, which, respectively, they
can sell on the market for money or supplies.
And this is their 20% profit from oil extraction from their land.
By the way, you can see at that screen there are also more complex schemes of concessions implemented, when a certain share of concessions was overbought by other majors - therefore, on the screenshot you can see such cases when a green (unbreakable) oil deal is not sold for free, but for some money (UK-USA/Netherl-USA/Rom-USA). These are cases of buying a share in someone else's concession. But this is very little money price, much lower than the true market price in game.
Only after the War and the fall of colonial systems, these countries managed to achieve better proportions of oil concessions such as 50% to 50%.
Before the WW2, only two countries in the world (not counting the colonial empires) fully owned their oil - USSR and Mexico.
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After sending 590 concession oil to USA and Britain (in ratio 70 to 30), 130 oil per day remains in Venezuela:
