The Pikka Field discovered by Armstrong Oil & Gas is just 2 to 3 miles wide, about 30 miles long, could produce 1.2 billion barrels of oil, and is one of three major finds that have shattered assumptions about what is possible in the most explored parts of Alaska’s North Slope. “The Armstrong discovery, and especially the size of that discovery, was stunning to everyone,” said David Houseknecht, a geologist for the US Geological Survey who has done multiple assessments of the potential in the area. “The thinking was the biggest oil pool we could imagine had 200 to 250 million barrels of recoverable oil. These discoveries coming in with more than a billion barrels or 300 million barrels, at least, really change things by an order of magnitude.” The find by Armstrong in March may not be the biggest of the three. A discovery by Caelus Energy in Smith Bay called Tulimaniq could produce twice as much oil though the development challenges are also much greater. And Conoco Phillips’ Willow discovery could ultimately produce from 3.3 to 3.9 billion, and add more than 400,000 B/D of production in the next decade. It is an impressive total, even when discounted for the fact that these are early estimates in a costly area for development in a period of struggling oil prices. In addition, what has been learned about identifying the subtle signs of oil trapped within two large formations—the Nanushuk and the Torok—could open up greater opportunities. The recent finds could turn the Nanushuk from a minor reservoir into a “virtually unexplored play fairway covering at least 9000 to 15000 km2 that includes both onshore and shallow offshore areas,” said Houseknecht. He made the comment during a presentation at the recent annual meeting of the American Association of Petroleum Geologists in Houston, where even poster sessions on the North Slope drew crowds. Those finds highlight advances in the tools used to look for oil pockets trapped in the earth, and unconventional techniques needed to maximize production from conventional reservoirs that are tighter than the free-flowing reservoirs found in the aging Prudhoe Bay field to the east. “The bottom line is, because of 3D seismic and because of the completion practices used for unconventionals, we can now reasonably look at low-permeable Brookian [Nanushuk and Torok] reservoirs as viable,” he said. One sign of the industry’s confidence was bidding at state and federal lease sales in December, where Conoco Phillips was the most aggressive bidder, picking up about 600,000 net acres, said Alison Wolters, a research analyst for Wood Mackenzie.