Oil - The World's Most Important Source of Energy


Petroleum or oil is a thick, yellow to black liquid found in rock layers. It is made up of organic material, formed millions of years ago from dead plants and animals.  Deep in the ground pressure and heat transformed them into oil.  Crude oil is oil in its natural state. Many other products are made out of petroleum. Every day our planet consumes about 90 million barrels of oil. Because oil needs millions of years to develop we will run out of the energy, which we so much depend on.


History of oil

Oil has been used in one form or another over thousands of years but it has become really important to our economy in the last 2 centuries. It has been the most important source of energy since the end of World War II.

The first oil well was created in the middle of the 19th century in Pennsylvania.  By 1870 oil production had spread to other American states. During the latter part of the 19th century oil was also produced in Canada and in European countries.

The automobile boom of the early 20th century led to a higher demand of oil. It played an important role as the main fuel for tanks and planes in the two world wars.

By 1950 the United States had become the world’s largest oil producer.  In the second part of the 20th century Saudi Arabia and Russia produced even more than the USA.

Today more than 90 percent of all vehicles are powered by oil products. It is the most important source of energy in our world.  About 80% of the world’s oil reserves are located in the Middle East. Other notable producers are Venezuela, Great Britain and Indonesia.


What  petroleum is made out of

Crude oil consists mainly of hydrocarbons, a combination of hydrogenand carbon. Each deposit of petroleum has a different combination of hydrocarbons, thus making it a thicker or thinner liquid. It also has sulphur, nitrogen and other elements in it.


How oil is produced

Before oil can be extracted from the earth geologists first must examine the land and the rock layers that lie underneath the surface. Up to about 30 years ago drilling for oil was a great risk. Geologists could not guarantee that oil would be found where they presumed. Today modern exploration methods make it possible to find oil with a 70% success rate.

Most of the world’s oil is produced by drilling into the crust of the earth. Crude oil is found together with gas, which floats above the oil layer.  Sometimes gas is extracted together with oil during the drilling process, at other times it is simply burned off when it comes to the surface.


Before oil can be brought to the surface a drilling rig is set up. Oil is often buried deep down in rock layers, so that drills must go down to a depth of 10000 meters and more. Offshore rigs operate on platforms in the ocean. They drill for oil underneath the ocean floor.

After it is brought up to the surface crude oil is brought to refineries, where it is made into petrol or gas, heating oil, kerosene, fuel for airplanes and plastic products. Other chemicals and fertilizers are also made out of crude oil.
Not all oil is found in rock below the surface. Some lies trapped in oil sands, but production is still expensive.


Petroleum industry

The oil industry combines many different tasks. In addition to exploring new reserves, drilling and refining oil, the industry must also bring oil products to the consumer.  Giant supertankers transport crude oil across the oceans all over the world. Pipelines bring oil over land from one part of a continent to another.


Price of oil

The price of oil changes constantly, depending on how much is produced and consumed. Many factors can influence the price of oil. Especially wars and conflicts in oil-producing countries can lead to a rise in oil prices.  The energy crisis of the 1970s, for example, led to a dramatic rise in oil prices and threw the world’s economy into a deep recession. The Organization of Petroleum Exporting Countries (OPEC) has had a great influence on production and the price of oil since the 1970s.


Oil consumption

Most of the world’s oil is needed in the western world.  The United States is the world’s largest oil consumer. It uses up about a fifth of the daily oil production. Japan, the European Union and China are other major consumers of oil.



Environmental effects of oil production

Producing and consuming oil and oil products affects our environment in many ways.

It is a major cause of global warming because burning fuel releases carbon dioxide, thus causing the greenhouse effect. Oil drilling is often damaging to the environment because chemicals are used to separate oil from water.

In the past decades there have been a series of tanker accidents that have polluted the world’s oceans and seas.  The biggest disaster was the sinking of the Exxon Valdez off the coast of Alaska in 1989.  In 2010 an oil spill in the Gulf of Mexico spread to coastal areas in the USA and Mexico and polluted thousands of square kilometers of water.


Related Topics


  • affect = to have an effect on, change
  • barrel = unit of measurement for oil = 159 liters
  • boom = time when something is very popular
  • burn off = burn without being used as energy
  • bury = here: covered by other rocks
  • carbon = chemical that exists in its pure form as diamonds; it is in coal and oil
  • carbon dioxide = gas that is produced when animals or people breathe out
  • cause = reason for
  • century = a hundred years
  • chemical = material produced in a chemical process
  • combine = bring together
  • constantly = all the time
  • consume = use, burn
  • consumer = person who buys or uses a product
  • crude oil = oil in its natural condition, the form in which it comes out of the earth
  • crust = hard outer layer of the earth
  • decade = ten years
  • demand = need
  • depend on = need
  • deposit = layer
  • develop = build up, grow
  • disaster = catastrophe; when something very bad happens
  • drill = make a hole into an  object
  • drilling rig = large structure on land or in the sea which has the machines for getting oil from under the ground
  • economy = the system by which a country’s goods and money are produced and used
  • environment = the world around us
  • especially = above all
  • examine = look at very closely
  • exploration = the process of looking for something , like oil or gold
  • extract = take out, remove
  • fertilizer = substance that you put into the ground in order to make plants grow better
  • fifth = 20 percent
  • float = move without sinking
  • fuel = material we use to produce energy -  like coal, oil or gas
  • geologist = person who studies rocks and the way they have changed since the earth was formed
  • giant = very big
  • greenhouse effect = the warming of the atmosphere; when light gets in and heat cannot get out
  • guarantee = promise
  • hydrocarbon = chemical compound that consists of hydrogen and carbon
  • hydrogen = colorless gas that forms water when put together with oxygen
  • in addition = also
  • influence = change, have an effect on
  • kerosene = clear oil that is burnt to provide heat or light
  • latter = second
  • layer = material between two other objects or material
  • liquid = fluid, watery material
  • major = important
  • nitrogen = gas that has no color and smell; it forms most of  the earth’s atmosphere
  • notable = important
  • offshore = in or under the sea, not far from the coast
  • oil spill = when oil leaks out into the ocean
  • organic = living things
  • platform = structure with machines and rooms on it
  • pollute = to make dirty
  • power = run
  • pressure = force, power, weight
  • presume = think, believe
  • recession = difficult time in the economy, when there is less trade and people do not buy so much; they also have fewer jobs
  • refinery = factory where crude oil is separated into its single elements and where other products are made out of oil
  • release = set free
  • reserves = here: oil that has not yet been discovered but probably lies deep under the surface
  • rise = if something goes up
  • role = part, function
  • separate = split, divide
  • series = a few
  • source of energy = here: where energy comes from
  • spread = extend, stretch, open out to
  • state = condition, shape, form
  • success = here: victory, win
  • sulphur = light yellow chemical that burns and has a very strong, unpleasant smell
  •  surface = top part of something
  • task = job
  • thus = that is why
  • trap = caught in a place and unable to escape
  • underneath = below
  • vehicle = machine that  has a motor and can take people from one place to another, like a car, bus or truck
  • well = deep hole in the ground