Chicontepec Formation
Petroleum field
The Chicontepec Basin is a petroleum system in Mexico north-east of Mexico City, covering an area of around 3,800 square kilometres in the states of Veracruz, Puebla and Hidalgo. Several oil fields have been discovered in that area since 1926. Wikipedia
Discovery: 1926
Estimated oil in place: 139,000 million barrels (~1.90×10^10 t)