ExxonMobil says a 9 billion barrel oilfield off the low-lying South American nation’s coast could soon outpace Permian production.

he case, before Guyana’s Constitutional Court, claims that Guyana’s approval of a massive, ExxonMobil-led oil and gas buildout off the country’s coast violates the government’s legal duty to protect the rights to a healthy environment, sustainable development, and the rights of future generations.