Advances in Petroleum Science and Technology

Petroleum is a substance that occurs naturally in a yellowish-black form. It is found in a liquid form in the geological formations underneath the Earth's surface. It includes all solid, liquid and gaseous hydrocarbons as well as crude oil. Under surface temperature and pressure, pentane and other heavier hydrocarbons exist in solid and liquid forms. Under the same conditions the lighter hydrocarbons such as methane, propane, ethane and butane exist in gaseous forms. Petroleum is a fossil f...