Post Carbon Fellow David Hughes research on unconventional oil is cited in this article at Inside Climate News.
From the article:
Canada is touted as having the third largest oil reserves in the world. But its supply of conventional oil is shrinking, and oil sands extraction has been growing fast in the past decade, from about 700,000 barrels per day in 2000 to 1.7 million today.
Hughes based his calculations on the 25.6 billion barrels of Canadian tar sands oil that are currently under active development. What concerns him more is the EROI of the estimated 143 billion additional barrels of oil sands that are sitting under Alberta's boreal forests, especially since only 8 percent of that oil is accessible via surface mining.
Image credit: Tar sands, Alberta - howlcollective/flickr