These are the barrels we got: wooden and metal, round and square. We will end our dive with a riddle that still awaits its Alexander the Great: where did the abbreviation bbl come from? According to the most common version, presented, for example, in the study "Standard Oil Co." written by the historian of the American oil industry Paul Henry Giddens in 1955, to distinguish barrels of oil from barrels of its refined products, they began to paint them in different colors: gasoline was transported in red barrels, and kerosene in blue ones. And this color differentiation of barrels was, of course, invented by John D. Rockefeller himself, since a society deprived of color differentiation of pants or barrels, as we know, "has no purpose." Since kerosene was the main product of refining at the initial stage of the industry's development, it determined the spelling of this abbreviation: "blue-barrel" – "bbl."