"Barrel" and "barrel of oil equivalent" (boe) sound almost identical, but they are fundamentally different kinds of quantity. Treating one as the other is a well-known error in oil-and-gas reporting, and the tool is built to prevent it.
Two different dimensions
- A barrel is a unit of volume: exactly
42 US gallons = 158.987294928 L. It measures how much space a liquid occupies. - A boe is a unit of energy, fixed by convention. It exists to express quantities of gas, coal or other fuels "in oil terms" for reporting.
Because one is a volume and the other is an energy, there is no direct conversion between them. Turning a physical barrel into an energy figure requires a fuel and a heating value — it is not a unit conversion.
The boe convention this tool uses
The tool adopts the widely-cited US convention:
1 boe = 5.8 MMBTU ≈ 6.1 GJ(the "5.8 MMBTU convention")
This is a standard definition: the number is exact by fiat. Every boe result states "boe (5.8 MMBTU convention)" and notes that other conventions exist, so a boe figure taken from a different source may differ by a few percent. It is a bookkeeping unit, not a measurement of any real barrel.
The physical barrel of crude is a separate, estimated quantity
Critically, the actual energy content of one physical barrel of crude oil is not the same as boe. It depends on the crude's grade and API gravity, and working it out needs a density — which this catalog does not have for crude oil, because no primary source for one was found. So a barrel of crude answers not available for mass and energy rather than borrowing the boe number or quoting a range nobody published. The fixed ~6.1 GJ boe convention remains what it always was: a definition, not a measurement of any particular oil.
So the tool never presents a specific crude's energy as exactly "boe", and never presents boe as the measured energy of the particular oil in question. For the family of oil-equivalent energy conventions (boe, toe, tce) and how they relate, see toe and oil-equivalent units.