Answer:
The most obvious potential benefit is turning desert land into arable land. As total arable land increases, the country will be able to grow more crops. As more crops are grown and harvested, the country will be able to feed larger populations without having to import large amounts of food. E.g. in many Arab nations, food and water are scarce and they are forced to import most of their food. If they didn't have oil exports, they wouldn't be able to pay for these imports.