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Crude oil is the natural form of oil when extracted from its source. The consistency can vary from being as thick as tar to as thin as gasoline. Crude oil is divided into three classifications with Class A being a light, volatile oil and Class D consisting of nonfluid oils. Each classification has different methods of extraction, treatment, and handling.
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In order to extract the most usefulness of crude, it must be refined into petroleum products such as gasoline, liquified petroleum gas (LPG), and kerosene. Refinement of crude oil also produces many other petrochemical products which can be used in plastics, rubbers, and fertilizers.
