CNBC | Companies claim largest US onshore oil discovery in 30 years CNBC Spanish energy company Repsol says an oil reserve of 1.2 billion barrels has been identified in Alaska's North Slope, which the company says is the largest onshore discovery in the United States in three decades. Repsol said that the contingent ... Repsol Discovers Major Oil Field in Alaska's North Slope Repsol finds massive new oil field in Alaska The largest onshore oil discovery in America for at least 30 years just happened in Alaska |