The amount of Energy in Crude Oil is 5,800,000 BTUs per barrel (42gal).
BTUs and Common Energy Sources
BTU stands for British Thermal Unit, and it is the amount of energy needed to heat one pound of water by one degree Fahrenheit.
Many common energy sources are used to generate energy measured in BTUs. The following is an excerpt from a U.S. Department of Energy guide listing the BTUs generated by energy products:
Time to Pump Deadweight Tonnage: Computes time to pump an amount of oil measured by DWT at a pumping rate. It also returns the volume pumped in barrels.