Fossil fuels include oil, natural gas and coal. Coal is commonly extracted through deep mining, but surface mining is a less expensive alternative. Oil is reached through the drilling of nonporous rock barriers that trap oil reserves. Workers drill porous rocks to reach natural gas reserves.
Coal can be converted into gas form to make a synthetic fuel similar to natural gas. Deep coal mining requires digging tunnels and shafts to reach coal seams, but automation has improved efficiency and safety standards. Coal is found all over the world, and the United States is one of the top exporters in the world. Western Europe, Japan and Canada are a few regions that benefit from U.S. coal exports.
Crude oil reserves are distributed throughout the world as well, but 63 percent of the world's oil reserves are concentrated in the Middle East. Oil is converted to make energy, plastics, inks, tires and pharmaceuticals. When oil is refined, it is separated into different hydrocarbons while removing impurities such as nitrogen, sulfur and heavy metals. Oil shale was never heated or fixed deeply enough to become oil, and it is 1,000 times more abundant than crude-oil reserves.
Natural gas is the gas by-product of oil and coal formations. It is used for cooking, heating and industrial purposes. Natural gas can be liquefied and shipped abroad. When natural gas is extracted, it flows to a processing center where liquid hydrocarbons, sulfur and carbon dioxide are removed.