ENERGY IN CONTEXT: A FOSSIL FUEL PRIMER - Hydrofracking: What Everyone Needs to Know - page 6

or was skimmed off of lakes, when petroleum leaked to the surface from underwa-
ter seeps. 16
On August 27, 1859, Edwin L. Drake struck oil in Titusville, Pennsylvania, set-
ting off what has become known as “the Oil Age.” Drake pumped oil from un-
derground into wooden barrels. As the oil business grew in the nineteenth century,
producers emulated distillers, who transported whiskey in 40-gallon barrels; oil-
men copied the idea, adding two gallons to account for spillage. This was signi-
ficant because it marked the first time purchasers knew exactly how much oil they
were acquiring. Although oil is no longer transported in barrels, it is still measured
in “barrels” (bbls), or the equivalent of 42 gallons. 17
Today, oil is the world's most popular fuel, representing 33.1 percent of global
energy use. 18 The EIA predicts global demand will jump from 98 million barrels
a day in 2020 to 112 million in 2035. 19 Nevertheless, the use of other fuels is also
surging, and oil has been losing market share. According to British Petroleum (BP),
oil's market share in 2012 was at its lowest point since the company began compil-
ing data in 1965. 20
To access oil, energy companies drill deep into the earth, then pump the oil from
deposits to the surface. It is sent to refineries by pipeline, ship, or barge. Crude oil
is considered “sweet” when it contains a small amount of sulfur, and “sour” when
it contains a lot of sulfur. Crude is further classified as “light,” which flows easily
like water, or “heavy,” which is thick and viscous like tar. 21
Oil refineries break down hydrocarbons into various commodities, known as
“refined products,” such as gasoline, diesel fuel, aviation fuel, heating oil, ker-
osene, asphalt, lubricants, propane, and the like. Oil can be converted into naphtha,
which is the “feedstock,” or basis, for high-octane gasoline or lighter fluid. Oil is
used to produce many other products, including fertilizers and plastics. As it is pro-
cessed, oil expands (much like popcorn growing bigger as it pops). A 42-gallon
barrel of crude oil generally produces 45 gallons of petroleum products. 22 The vast
majority—about 70 percent—of US petroleum consumption is used for transporta-
tion. 23
Gasoline—commonly referred to as “gas” in the United States (and “petrol” in
Great Britain), but not to be confused with natural gas—is a fuel made from pet-
roleum. At US refineries, gasoline is the main product produced from crude oil. In
2011, Americans used 367 million gallons of gasoline per day, the equivalent of
more than a gallon of gas per day for every citizen. 24

One 42-gallon barrel of re-