Spanish oil company Repsol and explorer Armstrong Energy have announced the discovery of what they said is the biggest onshore oil discovery the United States has seen in 30 years.
The find on state oil leases in the Nanushuk play on the North Slope could hold as much as 1.2 billion barrels of recoverable light oil, according to a Repsol news release.
The finds come after this winter's drilling of Horseshoe wells east of the Colville River and about 20 miles south from the Beaufort Sea coast. The well is an extension from the existing Pikka unit on the coast that the two had already been exploring. Repsol has been actively exploring in Alaska since 2008 and began drilling with Armstrong in 2011. 
The announcement notes that the first production from the find could make its way into the trans-Alaska oil pipeline system in 2021, with a rate near 120,000 barrels of oil per day. Throughput in the pipeline system has been on a long decline but saw an uptick in 2016 to average about 517,000 barrels of oil per day. The greatest throughput occurred Jan. 14, 1988, when 2,145,297 barrels moved through the pipeline.

Source: QNA