Ghawar vs. Permian Basin: Is There Even a Comparison? While some try to put the two enormous oil producers toe-to-toe, the best thing to do might be to understand why they are different. Take a quick look at some of the data points shaping upstream headlines and the movement of oil supplies around the world. Saudi Arabia is trying to push oil prices back up but US producers remain wary and uncertain. The First Eocene is a multibillion-barrel heavy-oil carbonate reservoir in the Wafra field, located in the Partitioned Zone between Saudi Arabia and Kuwait.