Taxonomy of Unconventional Oils:Chemical Makeup and Climate Considerations
Deborah GordonSenior Associate
Carnegie Energy & Climate ProgramFebruary 8, 2012
What Are Unconventional Oils?
•The term “unconventional oil” is synonymous with oil that cannot be produced, transported, or refined using traditional techniques
•The transition to unconventional oils might be viewed as a technologically and economically driven re-definition of the resource base for liquid hydrocarbon fuels
•The chemical make up of these petroleum resources—and their climate impacts—can be vastly different from one another and from conventional oil
Conventional Crude Oil
Hydrogen-rich hydrocarbon compounds with fewer carbon atoms and lower molecular weights
Crude continuum from high quality “light, sweet” crudes (Libya and Nigeria) to “heavy, sour” crudes (Venezuela)
Lighter, sweeter crudes have chemical make ups that yield today’s marketable petroleum products (gasoline, diesel, jet fuel)
C1 to C60 Molecular weight ~ 200
Oil Sands and
Heavy Oil
Contain large, carbon-laden hydrocarbon compounds Extra heavy oils (also called bitumen), are extremely
viscous – sometimes nearly solid Typically contain high concentrations of sulfur and
metals such as nickel and vanadium Require pre-processing into synthetic crude oil Removal by mining or in-situ with different impacts
Oil Shale
The petroleum component of the oil shale (kerogen) is less mature, and has not yet been fully transformed into oil or natural gas
Kerogen in the oil shale cannot be pumped directly from the ground or refined with traditional techniquesOil shale must be heated to high temperatures to transform the kerogen into an upgraded hydrocarbon product, similar to diesel
Tight Oils
Referred to as Shale OilProduced from low-permeability siltstones, sandstones, and carbonatesExtraction methods are unconventional—fracking and horizontal drillingOils vary but tend to have similar properties (density, sulfur content) as conventional oil productHeavier hydrocarbons, more diesel-like make up
• Unconventional oils are an evolving species of new petroleum fuels
• Their quality will change over time
Source: IEA, David Fyfe, http://csis.org/files/attachments/110621_Energy_Fyfe.pdf
As oil quality changes so do the processes to refine them and the products they yield
Greenhouse Gas EmissionsComparing Conventional and Unconventional Oils
•Life-cycle greenhouse gas (GHG) emissions from oil sands are reported to increase by 5 to 15 percent [per mile driven] compared to the average crude refined in the United States
•Well-to-wheel emissions are one measure to compare the lifecycle GHGs from motor vehicles using different fuels
•Per barrel produced and per energy produced, GHG emissions increases from unconventional oils are estimated to be significantly greater than conventional oil—3x or more
Climate Considerationsof Unconventional Oil Production
All fuels except CTL: IEA Energy Technology Network, May 2010, http://www.iea-etsap.org/web/E-TechDS/PDF/P02-Uncon%20oil&gas-GS-gct.pdf CTL: EU Fuels Directive Draft, 2009
Petroleum Fuel Low Emissions Estimate
g CO2/MJ
High Emissions Estimate
g CO2/MJ
AverageEmissions Estimate
g CO2/MJ
Average Increase
UO compared to Conventional Oil
Conventional Oil 4.4 4.7 4.6
Oil Sand and Heavy Oils 9.3 16 12.6 3x
Oil Shale 13 50 31.5 7x
Coal-to-Liquids (CTL) -- -- 101 22x
Managing Climate Impactsfrom Unconventional Oils
Global unconventional resources are massive and largely untapped
Unconventional oil in the ground may be far greater than all of the world’s currently economically recoverable conventional oil
The paradigm shift to UOs highlights the need for early and comprehensive assessment of the environmental and social impacts of resource development, including the need for mitigation strategies and long range planning
Climate, environmental, and other social factors are not being fully considered in early UO developments worldwide.
Greenhouse Gas Emissions
Critical aspects [of unconventional oils] are often not well understood—for instance, the greenhouse gas (GHG) emission intensity or effects on water supplies.
Source: National Petroleum Council, September 15, 2011
• New oils will replace the loss of more than one-half of global conventional oil production through 2035
• Understanding and managing GHGs from Unconventional Oils matters to maintain the 2 oC climate safety threshold
New Fuels Require New Rules
Source: ExxonMobil, The Outlook for Energy: A View to 2040, 2012
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