US oil producers face new challenges as top oilfield flags
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 - and may be nearing peak output. The Permian basin was the centerpiece of the shale revolution that began nearly two decades ago and spurred the U.S. to become the world's top oil producer, stealing market share from the Organization of the Petroleum Exporting Countries (OPEC) and other top producers. Slowing output growth and rising costs would make it difficult for oil producers to pump more and bring down oil prices to consumers, as envisioned by U.S. President Donald Trump in his "drill, baby, drill" mantra.