Oil refineries decompose oil compounds by heating into:

• Jet fuel.
• petrol.
• diesel.
• kerosene.
• Heavy asphalt for paving roads.

As for petrochemical plants, they treat petroleum compounds by complex chemical methods and turn them into materials that are useful in a field other than energy, producing products such as:

• plastic.
• Cleaning materials.
• Resin.
• Lubricant.
• petroleum jelly.
• radiator coolers
• Urea fertilizer for plants

etc.