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What are the different columns on a USGS oil and gas resource assessment table?

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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