Oil and gas estimates always involve some amounts of uncertainty. To account for this, the USGS presents its assessments of oil and gas potential in the form of a range based on how certain we are that this amount of oil and gas exist.
The USGS uses a statistically based process (or model) to calculate the likely range of its estimates. The range of values extends from a 5% or greater likelihood of occurrence (the F5 value, or largest estimated value) to less than 95% likelihood of occurrence (the F95 value, or smallest estimated value).
The F50 column is the value that occurs when 50% of the results are greater and 50% are lesser than the model results. We also calculate a mean or average value, which is the number commonly reported in the USGS press releases. The mean is close to, but not identical to, the F50 value.
Learn more: USGS Energy Assessments
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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
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 do the USGS and Bureau of Ocean Energy Management (BOEM) divide up which areas to be assessed for Oil and Gas Resources?
The USGS is responsible for oil and gas assessments onshore and in state waters (up to 3 miles offshore), while the Bureau of Ocean Energy Management (BOEM) assesses energy resources in the Federal offshore waters and the outer continental shelf. Learn more: USGS Energy Assessments
Does an assessment of the National Petroleum Reserve-Alaska mean there should or should not be oil and gas production in the Arctic National Wildlife Refuge?
The USGS is an unbiased, non-regulatory science agency, and therefore we do not advocate for or against oil and gas development in any location. The USGS role is to provide scientifically robust, publicly available estimates of potential resources so decision-makers have the best possible information to manage the Nation’s resources. Learn more: About USGS USGS Energy Assessments Alaska Petroleum...
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...
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- FAQ
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
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 do the USGS and Bureau of Ocean Energy Management (BOEM) divide up which areas to be assessed for Oil and Gas Resources?
The USGS is responsible for oil and gas assessments onshore and in state waters (up to 3 miles offshore), while the Bureau of Ocean Energy Management (BOEM) assesses energy resources in the Federal offshore waters and the outer continental shelf. Learn more: USGS Energy Assessments
Does an assessment of the National Petroleum Reserve-Alaska mean there should or should not be oil and gas production in the Arctic National Wildlife Refuge?
The USGS is an unbiased, non-regulatory science agency, and therefore we do not advocate for or against oil and gas development in any location. The USGS role is to provide scientifically robust, publicly available estimates of potential resources so decision-makers have the best possible information to manage the Nation’s resources. Learn more: About USGS USGS Energy Assessments Alaska Petroleum...
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...
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