OIL

   Origin: oil was formed from the remains of animals and plants that lived millions of years ago in a marine (water) environment before the dinosaurs. Over the years, the remains were covered by layers of mud.  Heat and pressure from these layers helped the remains turn into what we today call crude oil. The word "petroleum" means "rock oil" or "oil from the earth."

Extraction:

 Crude oil is usually found in underground areas called reservoirs.  Scientists and engineers explore a chosen area by studying rock samples from the earth.  Measurements are taken, and, if the site seems promising, drilling begins.  Above the hole, a structure called a 'derrick' is built to house the tools and pipes going into the well.  When finished, the drilled well will bring a steady flow of oil to the surface.

Transporting and Processing the oil

 After crude oil is removed from the ground, it is sent to a refinery by pipeline, ship or barge.  At a refinery, different parts of the crude oil are separated into useable petroleum products.  Crude oil is measured in barrels.