Earlier quoted context omitted.
" In a perfect free market the oil producers make zero profits" Where does this conclusion come from?
Don't quote me, it is ages since I had my economics book open last time, but if I recall correctly, there is a confusing terminology here. Zero profit means in the context of economice profits that exceed risk adjusted return . That is, even in a perfect market, in the models you are allowed to pay a decent return to your capital, but not more. These extra profits are called almost as confusingly "rents" in economics…
I would intuitively define a free market, as a (virtual) place, where people can trade freely (goods or labour) without restrictions. And they profit, if they are better off with the trade, than without. The more free the market, the less restrictions.
Why so complicated?