Crude Oil is a naturally occurring, yellow-to-black liquid found in geological formations beneath the Earth’s surface.
It consists of hydrocarbons of various molecular weights and other organic compounds. Crude oil is found accumulated in various porous rock formations in Earth’s crust and is extracted for burning as fuel or for processing into chemical products.
Oil is one of the most important commodities in the world playing an important part in some of the biggest industries like chemicals, transport, power, petrochemicals etc. A fossil fuel, petroleum/crude oil is formed when large quantities of dead organisms, usually zooplankton and algae, are buried underneath sedimentary rock and subjected to both intense heat and pressure. (1,2) Crude oils can be classified as heavy, medium, and light as follows:
Heavy: 10–20° API gravity
Medium: 20–25° API gravity
Light: above 25° API gravity
Crude Oil Reserves
The amount of crude oil that can be technically recovered at a cost that is financially feasible at the present price of oil. Following table shows the top ten countries having largest crude oil reserves. (3,4)
1. Venezuela – 300,878 million barrels
2. Saudi Arabia – 266,455 million barrels
3. Canada – 169,709 million barrels
4. Iran – 158,400 million barrels
5. Iraq – 142,503 million barrels
6. Kuwait – 101,500 million barrels
7. United Arab Emirates – 97,800 million barrels
8. Russia – 80,000 million barrels
9. Libya – 48,363 million barrels
10. United States – 39,230 million barrels
Top Crude Oil Producing OPEC Countries
OPEC is the Organization of Petroleum Exporting Countries (OPEC), which is a group consisting of 12 of the world’s major oil-exporting nations. OPEC was founded in 1960 to coordinate the petroleum policies of its members, and to provide member states with technical and economic aid. Following table is showing the crude oil production of top non-OPEC and OPEC countries for the year of 2016. (5)
Country Oil Production (Bbl/day) 2016
[World Production 80,622,000]
1 Russia 10,551,497
2 Saudi Arabia (OPEC) 10,460,710
3 United States 8,875,817
4 Iraq (OPEC) 4,451,516
5 Iran (OPEC) 3,990,956
6 China 3,980,650
7 Canada 3,662,694
8 United Arab Emirates(OPEC)3,106,077
9 Kuwait (OPEC) 2,923,825
10 Brazil 2,515,459
11 Venezuela (OPEC) 2,276,967
Transportation of Crude Oil
Getting oil to market is a process that requires various transportation and storage technologies, usually referred to as “midstream”. Oil is often produced in remote locations away from where it will be consumed; therefore, transportation networks have been built to transport the crude oil to refineries. Oil is normally transported by one of four options:
Processing of Crude Oil
Petroleum refinery is an industrial process plant where crude oil is transformed and refined into more useful products such as petroleum naphtha, gasoline, diesel fuel, asphalt base, heating oil, kerosene, liquefied petroleum gas, jet fuel and fuel oils.
Petrochemicals feed stock like ethylene and propylene can also be produced directly by cracking crude oil without the need of using refined products of crude oil such as naphtha. It is commonly refined into various types of fuels.
Components of petroleum are separated using a technique called fractional distillation i.e. separation of a liquid mixture into fractions differing in boiling point by means of distillation, typically using a fractionating column. This is called downstream industry in oil business.
Advantages of Crude Oil
• Crude oil has one of the highest energy densities which means that a small amount of oil can produce a large amount of energy. This makes it very useful as its high energy density has made it the preferred choice for use as fuel in automobiles.
• Crude oil is widely distributed in almost all parts of the world. Also there exists a massive infrastructure to transport oil to other places through ships, pipelines and tankers. This means that oil is available throughout the world.
• Crude oil is not very difficult to produce though most of the low cost locations have already been depleted. Now oil is being mined off the coasts in seas and also tar sands. Oil Refinery Technology is also quite old and mature which implies that refining of oil to get valuable products like diesel, petrol is also quite easy.
• Unlike solar and wind energy, oil can produce power 24/7 and is highly reliable. Oil engines are a mature technology and highly reliable to work with. (6,7)
Disadvantages of Crude Oil
• One of the biggest disadvantages of oil is that it releases carbon dioxide which has been sequestered for millions of years in the dead bodies of plant and animals.
• Oil spills have caused massive pollution of water bodies as massive oil supertankers lead oil. This can leads to the death of thousands of animals and fishes every year beside devastating the local ecology.
• Oil Plants emit harmful substances such as Sulfur Dioxide which cause health hazards among the surrounding population and Acid Rain.
• Oil exists as a mixture of hydrocarbons with traces of sulfur and other compounds. Refining of oil leads to production of harmful gases and solids like carbon monoxide and Plastic. (6,7)