The company is preparing for a third phase of exploration and appraisal drilling.
The company is focusing on selling Angola assets, addressing liquidity and moving discovered resources into production by 2021.
Mature basins continue to represent a vital source of fresh reserves in a cautious climate.
ExxonMobil saw its earnings fall in the second quarter to $1.7 billion, a nearly 60% drop from the same period in 2015.
News of a deepwater Gulf of Mexico discovery is made as the company reports falling profits and growth priorities.