Shell and INEOS Energy have struck oil at a deepwater exploration well in the U.S. Gulf of Mexico, confirming a new discovery in the high-pressure Norphlet formation. Shell and INEOS Energy said the Nashville exploration well encountered high-quality oil more than 26,000 feet below the seabed, according to industry reporting The well was drilled in deepwater acreage targeting the Norphlet play, a technically demanding formation associated with extreme pressure and temperature conditions that require advanced well design, specialized drilling fluids,…