Introduction of Petroleum: Petroleum is also known as crude oil. This occurs naturally underground. Oil also means rock oil. The term petroleum is a generic name applied to deposits of petroleum materials. Oil is found underground. It is a flammable liquid and mainly composed of various hydrocarbons and its average composition is 80 to 87%, H 11 to 15%, S 0.1 to 4%, N and O 0.1 to 0.55. Formation of petroleumPetroleum is evident from chromatographic, spectroscopic, and analytical studies demonstrating that a wide variety of organic and inorganic compounds are present in petroleum. Here are the common constituents found in oil. In the formation of petroleum hydrocarbons: Major constituents (nearly 70%); normal, branched and cycloalkanes are present; alkylbenzenes found in lower boiling point fractions; higher boiling point fractions contain polynuclear aromatics such as naphthalenes; terpenes are present to a lesser extent and explain the high specific turnovers of petroleum distillates. Sulfur-containing compounds: in the formation of petroleum, present in organic form...