Some Unconventional Sources: Tar Sands
Tar sand is one of the unconventional oil sources increasingly exploited in recent years; it is also referred to as bitumen. Canada is the country which produces the most oil from tar sands.
Despite the increase in the use of this source, however, the amount of oil that can be extracted from tar sands is still much smaller than that obtained from conventional sources.
According to Prof. Murray, “the use of tar sands really indicates that the high oil demand is forcing us to use even the most marginal sources.”
Shale Gas and Tight Oil
Shale gas and tight oil (oil derived by the shale formation) are other sources which received increasing interest.
The technology for the gas extraction improved remarkably in recent years; moreover, the US has several shale gas reserves. Previous calculations of the shale gas production, however, overestimated the amount of gas which could be supplied. “In the past we thought the US could produce natural gas from shale reserves for 100 years; now it is more realistic to think about a much shorter period, like 23 years,” Professor Murray told Decoded Science.
Considering tight oil, US has reserves which are currently exploited for oil production.
The efficiency of the oil extraction, however, is much lower in comparison with conventional oil sources. Prof. Murray explains:
“The Bakken in North Dakota is one of the most exploited tight oil sources. Here each well produces about 140 barrels of oil per day; from a conventional well, on the other hand, we can produce thousands of barrels per day. Moreover, the cost to extract the oil is quite high; the estimated price for commercial profitability is between 80 and 90 $ per barrel.”
Fuel Production: Long-term Implications
According to Professor Murray: “It is true that the US has several reservoirs of unconventional oil; this, however, does not mean our energy problems are resolved. It is not likely that the oil price will keep on decreasing; the oil production, on the other hand, will not increase. Both these factors can affect the US and world economies, which heavily rely on oil. A 4 % GDP growth, for instance, would require a 3 % increase in the oil supply. It seems difficult for this to happen. As a society, we may have to consider a different relationship between energy use and economic growth.”
Can we continue to grow, despite our inability to dramatically increase oil production? Only time will tell.
Murray, J.W. et al. Peak Oil and Energy Independence: Myth and Reality. (2013). EOS, Transactions, American Geophysical Union, 94(28), 245. Accessed July 21, 2013.
Murray, J.W. et al. Climate Policy: Oil´s tipping point has passed. (2012). Nature, 481, 433. Accessed July 21, 2013.
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