Petroleum, also known as crude oil and oil, is a naturally occurring, yellowish-black liquid found in geological formations. It is commonly refined into various fuels and chemicals. Components of petroleum are separated by means of distillation. Petroleum mainly consists of hydrocarbons as well as traces of other organic compounds.[1] The name petroleum covers both naturally occurring unprocessed crude oil and petroleum products that are made up of refined crude oil. A fossil fuel, petroleum is formed when large quantities of dead organisms, mostly zooplankton and algae, are buried underneath sedimentary rock and subjected to both prolonged heat and pressure. Petroleum has mostly been recovered by oil drilling. Drilling is carried out afte...