Once a cask that held crude, the oil barrel is now mostly an economic concept
An Object Lesson.
It travels between them on tanker ships, the largest of which can carry 3.7 million barrels.
When oil sells, it is priced per barrel, and when it burns, its energy output is measured in “barrel-of-oil equivalents” (5.8 × 106 BTUs). The world of oil is a world of…