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Circum-Arctic Resource Appraisal Summary

Core Content

The Circum-Arctic Resource Appraisal (CARA) is a comprehensive study conducted by the U.S. Geological Survey (USGS) to estimate undiscovered conventional oil and gas resources north of the Arctic Circle. The assessment was based on a geology-based probabilistic methodology and focused on 33 geologic provinces that were considered prospective for petroleum.

Key Findings

• Total Estimated Resources: The CARA estimates that approximately 90 billion barrels of oil, 1,669 trillion cubic feet of natural gas, and 44 billion barrels of natural gas liquids (NGL) may remain undiscovered in the Arctic.
• Offshore Dominance: About 84% of these resources are expected to occur in offshore areas.
• Exploration Status: While over 400 oil and gas fields have been discovered in onshore areas of Canada, Russia, and Alaska, most of the Arctic remains largely unexplored, especially its offshore regions.
• Unexplored Area: The Arctic Circle encompasses an area of over 21 million km², of which more than 7 million km² is on continental shelves under less than 500 meters of water, representing the geographically largest unexplored prospective area for petroleum.

Methodology

• The study used a geologic province-based approach, focusing on areas with at least a 10% probability of containing a significant petroleum accumulation.
• A world analog database was developed using the USGS World Petroleum Assessment 2000 to inform the probabilistic analysis.
• Assessment Units (AUs) were defined as mappable volumes of rock with common geologic traits, and each AU was evaluated for its probability of containing significant accumulations.
• Due to the limited seismic and drilling data in the Arctic, traditional assessment tools were not used. Instead, analog modeling and Monte Carlo simulations were employed to estimate the resource potential, incorporating uncertainties related to charge, reservoirs, traps, and timing.

Resource Distribution by Province

The following provinces were quantitatively assessed and ranked by their total oil and oil-equivalent natural gas (BOE) potential:

Summary of Resource Concentration

• Oil: Over 70% of the mean undiscovered oil resources are estimated to occur in Arctic Alaska, Amerasia Basin, East Greenland Rift Basins, East Barents Basin, and West Greenland-East Canada.
• Gas: Over 70% of the mean undiscovered natural gas resources are estimated to occur in West Siberian Basin, East Barents Basin, and Arctic Alaska.
• Offshore Focus: Approximately 84% of the total undiscovered oil and gas resources are expected to be located in offshore areas.

Exclusions and Assumptions

• Nonconventional Resources: The study excluded nonconventional resources such as coal bed methane, gas hydrate, oil shale, and tar sand.
• Recoverability: The assessment assumed that existing technology could recover resources, even in the presence of permanent sea ice and deep oceanic water.
• Economic Factors: The study did not consider economic viability or exploration and development costs, focusing solely on geological potential.

Conclusion

The CARA study provides a geological risked estimate of the undiscovered conventional oil and gas resources in the Arctic, highlighting the vast potential of the region, particularly in offshore areas. The findings underscore the importance of further exploration and scientific research to better understand and assess these resources, given the limited current data and the frontier nature of many Arctic provinces.

References

• Charpentier, R.R., Klett, T.R., and Attanasi, E.D., 2008, Database for assessment unit-scale analogs (exclusive of the United States): U.S. Geological Survey Open-File Report 2007-1404.
• USGS World Assessment Team, 2000, U.S. Geological Survey World Petroleum Assessment 2000—Description and Results: U.S. Geological Survey Digital Data Series - DDS60.