first, you got most available structures early in game and in my case i were not able to cover all oilfields as USA in the USA.
resources were cut down in early game and will be set free with prospector event after some years...
same is true for rubber.
i sold about 10 oil to the world market in 1885 and 11 to my people.
second,
you have just to look for the folder with the structures on your HDD and have a clear eye for level three structures (or higher if there are any higher) for your nation. thats all, done in 10 minutes.
certainly coal, as historically, will do you a great deal until the Great War, 6 years before the game ends
while oil fractioning was known since half a century ago, in 1890s Benzin was sold in pharmacies and electrical powered cars already in use in 1882.
no large industries, no need for a large refinery, no major use of oil for 45-50 years
