In a world running low on oil, several countries are still sitting on massive supplies. If only they could get to them. The Ferdows, Mound, and Zageh Fields Location: The Persian Gulf, off the coast of southern Iran Estimated Reserves: 38 billion barrels Details: Discovered in 2003, these three interconnected fields are among the largest oil deposits ever found. Ferdows is the largest, with 30.6 billion barrels. This figure may seem astounding, but it’s usually not possible to extract all the oil from a field due to technological and financial constraints. Plus, assessing how much oil these deposits can actually...