Some areas in the Permian have hit geological limits while others, yet to be drilled, are not expected to be as prolific as the prime Tier 1 acreage. Despite record U.S. crude oil production ...

NEW YORK/HOUSTON, March 27 (Reuters) - U.S. oil producers are grappling with geological limits to production growth as the country's top oilfield ages and produces more water and gas and less oil ...

Dating to the Cretaceous period, the geological era between 145.5 and 66 ... states could yield as much as 28 million barrels of oil and nearly 36 trillion cubic feet of natural gas.