Christopher J. Schenk Craig J. Wandrey Ronald R. Charpentier Michael E. Brownfield Janet K. Pitman Richard M. Pollastro Troy A. Cook Marilyn E. Tennyson T. R. Klett 2011 Using a geology-based assessment methodology, the U.S. Geological Survey estimated volumes of undiscovered, technically recoverable, conventional petroleum resources for the North Sakhalin Basin Province of Russia. The mean volumes were estimated at 5.3 billion barrels of crude oil, 43.8 trillion cubic feet of natural gas, and 0.8 billion barrels of natural gas liquids. application/pdf 10.3133/fs20113149 en U.S. Geological Survey Assessment of undiscovered oil and gas resources of the North Sakhalin Basin Province, Russia, 2011 reports