Refining oil: crude oil extracted by a well cannot be used as it is, it need to be transported to refinery by pipeline, truck, rail or ship. Refining is the crude is heated in pressurized vessels to separate it into carious fuels and other components with different boiling points. this process decrease the net energy of oil since it requires a large input of energy Petrochemicals are used as raw materials to make industrial organic chemicals, cleaning fluids, pesticides, plastics, plastics, synthetic fibers, paints, medicines, and many other products