Complex sentence: The field was nicknamed in honor of the Tupi people and later named after former Brazilian president Luiz Inacio da Silva and is considered to be the Western Hemisphere's largest oil discovery of the last 30 years.
Split into simpler sentences: The field was nicknamed in honor of the Tupi people and later named after former Brazilian president Luiz Inacio da Silva. It is considered to be the Western Hemisphere's largest oil discovery of the last 30 years.