The USGS regularly re-examines our assessments to see if updated information warrants a reassessment. Sometimes more information is available either from USGS research or industry production, and the USGS decides to conduct a new assessment.
Learn more: USGS Energy Assessments
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What is the difference between the National Petroleum Reserve-Alaska and the Arctic National Wildlife Refuge?
The National Petroleum Reserve-Alaska (NPR-A) is a roughly 23.4 million acre area of Federal land managed by the Bureau of Land Management. It lies in northwest Alaska and borders both the Chukchi Sea to the west and the Beaufort Sea to the north. The NPR-A was originally established in 1923 as a petroleum reserve for the U.S. Navy, then transferred to the Department of the Interior in 1976. The...
Does the Bakken Formation contain more oil than Saudi Arabia?
Probably not. In 2000, the USGS assessed undiscovered, technically recoverable oil and gas resources in Saudi Arabia at 87 billion barrels (USGS 2000 World Petroleum Assessment) compared to a mean estimate of 4.3 billion barrels of undiscovered, technically recoverable continuous oil in the Bakken and Three Forks formations (USGS 2021 Bakken and Three Forks Assessment). In addition, Saudi Arabia...
How is hydraulic fracturing related to earthquakes and tremors?
Reports of hydraulic fracturing causing felt earthquakes are extremely rare. However, wastewater produced by wells that were hydraulic fractured can cause “induced” earthquakes when it is injected into deep wastewater wells. Wastewater disposal wells operate for longer durations and inject much more fluid than the hydraulic fracturing operations. Wastewater injection can raise pressure levels in...
What are "technically recoverable" oil and gas resources?
“Technically recoverable” means that the oil and/or gas can be produced using currently available technology and industry practices. This is regardless of any economic or accessibility considerations. For example, the technology required to produce oil from a location might exist, but it costs more than the oil is worth. The oil is still technically recoverable. Learn more: USGS Energy Assessments...
What is the difference between assessed oil and gas “resources” and “reserves”?
“Reserves” are quantities of oil and gas that are already discovered, recoverable, and commercial. Domestic reserves are tracked by the U.S. Energy Information Administration. The USGS assesses “undiscovered, technically recoverable resources,” which are those that are estimated to exist based on geologic knowledge and theory. Learn more: USGS Energy Resource Assessments
Related Content
- FAQ
What is the difference between the National Petroleum Reserve-Alaska and the Arctic National Wildlife Refuge?
The National Petroleum Reserve-Alaska (NPR-A) is a roughly 23.4 million acre area of Federal land managed by the Bureau of Land Management. It lies in northwest Alaska and borders both the Chukchi Sea to the west and the Beaufort Sea to the north. The NPR-A was originally established in 1923 as a petroleum reserve for the U.S. Navy, then transferred to the Department of the Interior in 1976. The...
Does the Bakken Formation contain more oil than Saudi Arabia?
Probably not. In 2000, the USGS assessed undiscovered, technically recoverable oil and gas resources in Saudi Arabia at 87 billion barrels (USGS 2000 World Petroleum Assessment) compared to a mean estimate of 4.3 billion barrels of undiscovered, technically recoverable continuous oil in the Bakken and Three Forks formations (USGS 2021 Bakken and Three Forks Assessment). In addition, Saudi Arabia...
How is hydraulic fracturing related to earthquakes and tremors?
Reports of hydraulic fracturing causing felt earthquakes are extremely rare. However, wastewater produced by wells that were hydraulic fractured can cause “induced” earthquakes when it is injected into deep wastewater wells. Wastewater disposal wells operate for longer durations and inject much more fluid than the hydraulic fracturing operations. Wastewater injection can raise pressure levels in...
What are "technically recoverable" oil and gas resources?
“Technically recoverable” means that the oil and/or gas can be produced using currently available technology and industry practices. This is regardless of any economic or accessibility considerations. For example, the technology required to produce oil from a location might exist, but it costs more than the oil is worth. The oil is still technically recoverable. Learn more: USGS Energy Assessments...
What is the difference between assessed oil and gas “resources” and “reserves”?
“Reserves” are quantities of oil and gas that are already discovered, recoverable, and commercial. Domestic reserves are tracked by the U.S. Energy Information Administration. The USGS assesses “undiscovered, technically recoverable resources,” which are those that are estimated to exist based on geologic knowledge and theory. Learn more: USGS Energy Resource Assessments
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