Unconventional oil production (whether from shale or oil sands) is an energy-intensive process, and emits more CO2 than conventional extractive methods do.

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Environmentalists strongly oppose shale-gas extraction due to fears that fracking may contaminate water supplies, the oil-sands industry because it is energy-intensive and dirty, and deep-water drilling because of the risk of oil spills like last year's Gulf of Mexico disaster.

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It also has its hand in oil sands, solar, fuel cells and a variety of other alternative energy initiatives worldwide.

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These pipelines will distribute gas from the fracked shales and deliver oil from the tar sands, giving us the biggest energy boom in 60 years.

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But technological advances and improvements in recovery methods, as well as reduction of water usage and greenhouse gas emissions, have made oil sands a viable and popular option for the future of U.S. energy.

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Potential targets include producers in the Canadian oil sands such as Canadian Natural Resources and Nexen, said Peter Churcher, executive vice president of Eagle Energy and a former executive with the Abuu Dhabi National Energy Company.

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