I think that a better translation of the Spanish "Yacimientos Petroliferos Fiscal"
is “Government Petroleum Deposits”.
This would denote a Government (nationalised) Control of Argentine petroleum deposits (onshore and offshore)…as was the case from the Peron regime onwards.
The Term “Fiscal” in Spanish relates to the State Procurator (Legal) and also to things relating to the Functions of Gov’t, such as the Treasury (Fiscalia) etc.
The term “Fiscal” is also used in Scotland, to denote the Crown Prosecutor
( the Office of the Procurator Fiscal) and in general English usage to relate to the Financial world, as controlled by Government regulations etc. (Fiscal Year, etc). Other Romance Languages ( Italian etc) also use the term “Fiscal” in similar meanings.
Of course, I would not try to teach a Native Spanish speaker how to speak his own language, but sometimes there are Nuances in translation which may not be immediately evident.