Royal Dutch Shell (NYSE:RDS-A) just announced that it will drill the world's deepest well -- nearly two miles below the ocean's surface -- in the Gulf of Mexico. This sort of ambitious project is all that's left for the oil majors clamoring to boost production. In this video, contributor Aimee Duffy looks at ExxonMobil (NYSE:XOM) and its similar quest to develop the technically challenging Julia oil field, also located in the Gulf.