Petroleum Refining

See also Petroleum Products and Petroleum.

Since the first producing oil (petroleum) well was drilled at Titusville, PA, in 1859, over 2 million bore holes have been sunk around the world.   Since many of these are "dry", oil drilling is a very risky and expensive industry.   The first oil wells were drilled on land.   However, thanks to advanced drilling technology, "offshore" wells are now drilled in oceans.   Oil drills are rotating drill "bits" at the end of a series of connected drill pipes, each of which is about 30 feet long and 4 to 6 inches in diameter.   The shaft of connected pipes may be up to 3 miles long.   Originally made of steel, current drill bits are made of diamond or tungsten carbide.   Drilling rates range from 1 foot / hour in extremely hard rock to 100 yards per hour in soft soil.   A high derrick is used to fit the pipes together, hold the shaft, and rotate it at about 120 rpm's (revolutions per minute).   All the pipes must be removed in sections of 3 pipes when the drill bit becomes dull and has to be replaced.   The pipes are then fitted together, lowered, and the drilling process begins again.   During drilling, a specially prepared mud is pumped into the pipes and through the bit to cool and lubricate the shaft and bit.   The mud also flushes debris to the surface where it is removed so that the mud can be reused. ^{How 756}

Before 1859

1859-1869

1870-1879

1880-1889

1890-1899

1900-1909

1910-1919

1920-1929

1930-1939

1940-1949

1950-1959

1960-1969

1970-1979

1980-1989

1990-1999