consisting of a complex mixture of hydrocarbon
s of various molecular weights and other liquid organic compound
s, that are found in geologic formations beneath the Earth's
surface. Petroleum is recovered mostly through oil drilling. This latter stage comes after the studies of structural geology (at the reservoir scale), sedimentary basin analysis, reservoir characterization (mainly in terms of porosity and permeable structures).
1859 Petroleum is discovered in Titusville, Pennsylvania leading to the world's first commercially successful oil well.
1901 The first great Texas oil gusher is discovered at Spindletop in Beaumont, Texas.
1922 Teapot Dome scandal: United States Secretary of the Interior leases Teapot Dome petroleum reserves in Wyoming.
1938 Oil is discovered in Saudi Arabia.
1938 Mexico nationalizes all foreign-owned oil properties within its borders.
1973 OPEC starts an oil embargo against a number of western countries, considered to have helped Israel in its war against Syria.
1979 Iran hostage crisis: In response to the hostage situation in Tehran, US President Jimmy Carter orders a halt to all petroleum imports into the United States from Iran.
1984 San Juanico Disaster: A series of explosions at the PEMEX petroleum storage facility at San Juan Ixhuatepec in Mexico City starts a major fire and kills about 500 people.
1989 Exxon Valdez oil spill: In Prince William Sound in Alaska, the ''Exxon Valdez'' spills 240,000 barrels (42,000 m³) of petroleum after running aground.