Electrical-submersible-pump (ESP) technology is a proven artificial-lift method for shallow, low-pressure reservoirs such as those found in the West Sak viscous oil field in Alaska. The green light comes 4 years after the privately-held firm filed its development and production plan. Liberty Island would consist of gravel, stretch 9 acres, and sit just a few miles offshore. Major oil discoveries by Armstrong Oil & Gas and ConocoPhillips have compelled the US Department of the Interior to reassess its estimate of undiscovered, technically recoverable resources in parts of Alaska. ConocoPhillips is producing more oil from the North Slope as it advances development of the massive, historic region.