Crude oil

Crude oil is a naturally-occurring substance found in certain rock formations in the earth. It is a dark, sticky liquid which, scientifically speaking, is classified as a hydrocarbon. This means, it is a compound containing carbon and hydrogen, with or without non-metallic elements such as oxygen and sulfur. Crude oil is highly flammable and can be burned to create energy. Along with its sister hydrocarbon, natural gas, derivatives from crude oil make an excellent fuel.

Crude oil is measured in barrels. When crude oil first came into large-scale commercial use in the United States in the 19th century, it was stored in wooden barrels. One barrel equals 42 US gallons, or 159 litres. In some cases crude oil is also measured in tons. The number of barrels contained in each ton vary depending on the type and specific gravity of each crude, however the average number considered would be around 7.33 barrels per each ton.

World proven crude oil reserves are estimated at almost 1.5 trillion barrels, of which OPEC Member Countries hold approximately 81 per cent.

OPEC's Members in 2010 produced around 29.2 million barrels per day of crude oil, or 41.8 per cent of the world total output, which stood at about 69.7 million barrels per day.

At the rate of production in 2010, OPEC crude oil reserves are sufficient to last more than 112 years.

Burning crude oil itself is of limited use. To extract the maximum value from crude, it first needs to be refined into petroleum products. The best-known of these is gasoline, or petrol. However, there are many other products that can be obtained when a barrel of crude oil is refined. These include liquefied petroleum gas (LPG), naphtha, kerosene, gasoil and fuel oil. Other useful products which are not fuels can also be manufactured by refining crude oil, such as lubricants and asphalt (used in paving roads). A range of sub-items like perfumes and insecticides are also ultimately derived from crude oil.

Furthermore, several of the products listed above which are derived from crude oil, such as naphtha, gasoil, LPG and ethane, can themselves be used as inputs or feedstocks in the production of petrochemicals. There are more than 4,000 different petrochemical products, but those which are considered as basic products include ethylene, propylene, butadiene, benzene, ammonia and methanol. The main groups of petrochemical end-products are plastics, synthetic fibres, synthetic rubbers, detergents and chemical fertilisers.

Considering the vast number of products that are derived from it, crude oil is a very versatile substance. Life as we know it today would be extremely difficult without crude oil and its by-products.