The Permian Basin of Texas and New Mexico holds 60 billion to 70 billion barrels of yet-to-be pumped crude oil, says a new study.

The Permian region’s so-called recoverable resources would be enough to supply every refinery in the US for 12 years and have a market value of about $3.3 trillion at current prices, according to UK-based information services company IHS Markit.

IHS spent three years studying output data from more than 440,000 wells to calculate the amount of crude remaining within the sprawling, mile-thick rock formation that pumps more oil than any other US field, Bloomberg reported this week. The estimate may grow as IHS geologists and data scientists extend their analytical techniques to deeper geological zones.

“The Permian Basin is America’s super basin in terms of its oil and gas production history and for operators it presents a significant variety of stacked targets that are profitable at today’s oil prices,” Prithiraj Chungkham, director of unconventional resources for IHS, said in a statement.

The assessment may boost Pioneer Natural Resources Chairman Scott Sheffield’s claim that the Permian is a 75 billion-barrel field that may rival Saudi Arabia’s massive Ghawar field. Last November, the US Geological Survey estimated that just one layer of the Permian,  known as the Wolfcamp, holds 20 billion barrels of crude.

img: Encana Corp.