From Longman Dictionary of Contemporary Englishoil-richˌoil-ˈrich adjective [only before noun] British English an oil-rich country has plenty of natural oil under the ground from which it is able to make a lot of money the oil-rich Gulf States
Examples from the Corpus
oil-rich• But this had to be reconciled with the need for good relations with the oil-rich Arab countries.• We know oil-rich regimes purchase their safety and others a dubious new credibility in Western eyes.• Raimondo, the designer, was frantic; an oil-rich sheikh was coming in for a private showing with his wives.• Then along came the Gulf's oil boom and Western banks found themselves flooded with investments from oil-rich sheikhs.• Yet at the last count there were six oil-rich states bordering the Gulf. 