ABSTRACT
The terms oil and petroleum have been used interchangeably by industry since the early 1900s. However, there are some who refer to petroleum as the crude oil prior to any treatment/reŸnery, with oil reserved as the deŸnition of “any of the various kinds of greasy, combustible substances obtained from animal, vegetable, and mineral sources, and liquid at ordinary temperature.” Both terms are employed interchangeably in this chapter as a matter of convenience. The typical petroleum reservoirs are mostly sandstone or limestone formation containing oil. The viscosity of the oil in these formations may be as thin as gasoline or as thick as tar. It may be almost clear or black. Petroleum, created by the decay of biological materials similar to those creating coal, is called a nonrenewable energy source because it takes millions of years to form. At present, full-scale technologies are not available to make oil in large quantities.
