The Full Wiki

petroleum: Wikis


Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.


Oil exports imports difference
pumping an oil well near Lubbock, Texas]]

Petroleum (L. petroleum, from Greek πετρέλαιον, lit. "rock oil") or crude oil is a naturally occurring, flammable liquid found in rock formations in the Earth consisting of a complex mixture of hydrocarbons of various molecular weights, plus other organic compounds.

The term "petroleum" was first used in the treatise De Natura Fossilium, published in 1546 by the German mineralogist Georg Bauer, also known as Georgius Agricola.[1]



The proportion of hydrocarbons in the mixture is highly variable and ranges from as much as 97% by weight in the lighter oils to as little as 50% in the heavier oils and bitumens.

The hydrocarbons in crude oil are mostly alkanes, cycloalkanes and various aromatic hydrocarbons while the other organic compounds contain nitrogen, oxygen and sulfur, and trace amounts of metals such as iron, nickel, copper and vanadium. The exact molecular composition varies widely from formation to formation but the proportion of chemical elements vary over fairly narrow limits as follows:[2]

Composition by weight
Element Percent range
Carbon 83 to 87%
Hydrogen 10 to 14%
Nitrogen 0.1 to 2%
Oxygen 0.1 to 1.5%
Sulfur 0.5 to 6%
Metals less than 1000 ppm

Four different types of hydrocarbon molecules appear in crude oil. The relative percentage of each varies from oil to oil, determining the properties of each oil.[3]

Composition by weight
Hydrocarbon Average Range
Paraffins 30% 15 to 60%
Naphthenes 49% 30 to 60%
Aromatics 15% 3 to 30%
Asphaltics 6% remainder

Crude oil varies greatly in appearance depending on its composition. It is usually black or dark brown (although it may be yellowish or even greenish). In the reservoir it is usually found in association with natural gas, which being lighter forms a gas cap over the petroleum, and saline water which, being heavier than most forms of crude oil, generally sinks beneath it. Crude oil may also be found in semi-solid form mixed with sand and water, as in the Athabasca oil sands in Canada, where it is usually referred to as crude bitumen. In Canada, bitumen is considered a sticky, tar-like form of crude oil which is so thick and heavy that it must be heated or diluted before it will flow.[4] Venezuela also has large amounts of oil in the Orinoco oil sands, although the hydrocarbons trapped in them are more fluid than in Canada and are usually called extra heavy oil. These oil sands resources are called unconventional oil to distinguish them from oil which can be extracted using traditional oil well methods. Between them, Canada and Venezuela contain an estimated 3.6 trillion barrels (570×10^9 m3) of bitumen and extra-heavy oil, about twice the volume of the world's reserves of conventional oil.[5]

Petroleum is used mostly, by volume, for producing fuel oil and gasoline (petrol), both important "primary energy" sources.[6] 84% by volume of the hydrocarbons present in petroleum is converted into energy-rich fuels (petroleum-based fuels), including gasoline, diesel, jet, heating, and other fuel oils, and liquefied petroleum gas.[7] The lighter grades of crude oil produce the best yields of these products, but as the world's reserves of light and medium oil are depleted, oil refineries are increasingly having to process heavy oil and bitumen, and use more complex and expensive methods to produce the products required. Because heavier crude oils have too much carbon and not enough hydrogen, these processes generally involve removing carbon from or adding hydrogen to the molecules, and using fluid catalytic cracking to convert the longer, more complex molecules in the oil to the shorter, simpler ones in the fuels.

Due to its high energy density, easy transportability and relative abundance, oil has become the world's most important source of energy since the mid-1950s. Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics; the 16% not used for energy production is converted into these other materials.

Petroleum is found in porous rock formations in the upper strata of some areas of the Earth's crust. There is also petroleum in oil sands (tar sands). Known reserves of petroleum are typically estimated at around 190 km3 (1.2 trillion (short scale) barrels) without oil sands,[8] or 595 km3 (3.74 trillion barrels) with oil sands.[9] Consumption is currently around 84 million barrels (13.4×10^6 m3) per day, or 4.9 km3 per year. Because the energy return over energy invested (EROEI) ratio of oil is constantly falling (due to physical phenomena such as residual oil saturation, and the economic factor of rising marginal extraction costs), recoverable oil reserves are significantly less than total oil in place. At current consumption levels, and assuming that oil will be consumed only from reservoirs, known recoverable reserves would be gone around 2039, potentially leading to a global energy crisis. However, there are factors which may extend or reduce this estimate, including the rapidly increasing demand for petroleum in China, India, and other developing nations; new discoveries; energy conservation and use of alternative energy sources; and new economically viable exploitation of unconventional oil sources.


, a hydrocarbon found in petroleum, lines are single bonds, black spheres are carbon, white spheres are hydrogen]] Petroleum is a mixture of a very large number of different hydrocarbons; the most commonly found molecules are alkanes (linear or branched), cycloalkanes, aromatic hydrocarbons, or more complicated chemicals like asphaltenes. Each petroleum variety has a unique mix of molecules, which define its physical and chemical properties, like color and viscosity.

The alkanes, also known as paraffins, are saturated hydrocarbons with straight or branched chains which contain only carbon and hydrogen and have the general formula CnH2n+2 They generally have from 5 to 40 carbon atoms per molecule, although trace amounts of shorter or longer molecules may be present in the mixture.

The alkanes from pentane (C5H12) to octane (C8H18) are refined into gasoline (petrol), the ones from nonane (C9H20) to hexadecane (C16H34) into diesel fuel and kerosene (primary component of many types of jet fuel), and the ones from hexadecane upwards into fuel oil and lubricating oil. At the heavier end of the range, paraffin wax is an alkane with approximately 25 carbon atoms, while asphalt has 35 and up, although these are usually cracked by modern refineries into more valuable products. The shortest molecules, those with four or fewer carbon atoms, are in a gaseous state at room temperature. They are the petroleum gases. Depending on demand and the cost of recovery, these gases are either flared off, sold as liquified petroleum gas under pressure, or used to power the refinery's own burners. During the winter, Butane (C4H10), is blended into the gasoline pool at high rates, because butane's high vapor pressure assists with cold starts. Liquified under pressure slightly above atmospheric, it is best known for powering cigarette lighters, but it is also a main fuel source for many developing countries. Propane can be liquified under modest pressure, and is consumed for just about every application relying on petroleum for energy, from cooking to heating to transportation.

The cycloalkanes, also known as naphthenes, are saturated hydrocarbons which have one or more carbon rings to which hydrogen atoms are attached according to the formula CnH2n. Cycloalkanes have similar properties to alkanes but have higher boiling points.

The aromatic hydrocarbons are unsaturated hydrocarbons which have one or more planar six-carbon rings called benzene rings, to which hydrogen atoms are attached with the formula CnHn. They tend to burn with a sooty flame, and many have a sweet aroma. Some are carcinogenic.

These different molecules are separated by fractional distillation at an oil refinery to produce gasoline, jet fuel, kerosene, and other hydrocarbons. For example 2,2,4-trimethylpentane (isooctane), widely used in gasoline, has a chemical formula of C8H18 and it reacts with oxygen exothermically:[10]

2\mathrm{C}_8 \mathrm{H}_{18(l)} + 25\mathrm{O}_{2(g)} \rightarrow \; 16\mathrm{CO}_{2(g)} + 18\mathrm{H}_2 \mathrm{O}_{(l)} + 10.86 \ \mathrm{MJ}

The amount of various molecules in an oil sample can be determined in laboratory. The molecules are typically extracted in a solvent, then separated in a gas chromatograph, and finally determined with a suitable detector, such as a flame ionization detector or a mass spectrometer[11].

Incomplete combustion of petroleum or gasoline results in production of toxic byproducts. Too little oxygen results in carbon monoxide. Due to the high temperatures and high pressures involved, exhaust gases from gasoline combustion in car engines usually include nitrogen oxides which are responsible for creation of photochemical smog.


Geologists view crude oil and natural gas as the product of compression and heating of ancient organic materials (i.e. kerogen) over geological time. Formation of petroleum occurs from hydrocarbon pyrolysis, in a variety of mostly endothermic reactions at high temperature and/or pressure.[12] Today's oil formed from the preserved remains of prehistoric zooplankton and algae, which had settled to a sea or lake bottom in large quantities under anoxic conditions (the remains of prehistoric terrestrial plants, on the other hand, tended to form coal). Over geological time the organic matter mixed with mud, and was buried under heavy layers of sediment resulting in high levels of heat and pressure (known as diagenesis). This caused the organic matter to chemically change, first into a waxy material known as kerogen, which is found in various oil shales around the world, and then with more heat into liquid and gaseous hydrocarbons in a process known as catagenesis.

Geologists often refer to the temperature range in which oil forms as an "oil window"[13]—below the minimum temperature oil remains trapped in the form of kerogen, and above the maximum temperature the oil is converted to natural gas through the process of thermal cracking. Although this temperature range is found at different depths below the surface throughout the world, a typical depth for the oil window is 4–6 km. Sometimes, oil which is formed at extreme depths may migrate and become trapped at much shallower depths than where it was formed. The Athabasca Oil Sands is one example of this.

Abiogenic origin

A number of geologists in Russia adhere to the abiogenic petroleum origin hypothesis and maintain that hydrocarbons of purely inorganic origin exist within Earth's interior. Astronomer Thomas Gold championed the theory in the Western world by supporting the work done by Nikolai Kudryavtsev in the 1950s. It is currently supported primarily by Kenney and Krayushkin.[14]

The abiogenic origin hypothesis lacks scientific support. Extensive research into the chemical structure of kerogen has identified bacterial cells as the primary source of oil. The abiogenic origin hypothesis fails to explain the presence of these markers in kerogen and oil, as well as failing to explain how inorganic origin could be achieved at temperatures and pressures sufficient to convert kerogen to graphite. It has not been successfully used in uncovering oil deposits by geologists, as the hypothesis lacks any mechanism for determining where the process may occur.[15]

Crude oil

Crude oil reservoirs

Three conditions must be present for oil reservoirs to form: a source rock rich in hydrocarbon material buried deep enough for subterranean heat to cook it into oil; a porous and permeable reservoir rock for it to accumulate in; and a cap rock (seal) or other mechanism that prevents it from escaping to the surface. Within these reservoirs, fluids will typically organize themselves like a three-layer cake with a layer of water below the oil layer and a layer of gas above it, although the different layers vary in size between reservoirs. Because most hydrocarbons are lighter than rock or water, they often migrate upward through adjacent rock layers until either reaching the surface or becoming trapped within porous rocks (known as reservoirs) by impermeable rocks above. However, the process is influenced by underground water flows, causing oil to migrate hundreds of kilometres horizontally or even short distances downward before becoming trapped in a reservoir. When hydrocarbons are concentrated in a trap, an oil field forms, from which the liquid can be extracted by drilling and pumping.

The reactions that produce oil and natural gas are often modeled as first order breakdown reactions, where hydrocarbons are broken down to oil and natural gas by a set of parallel reactions, and oil eventually breaks down to natural gas by another set of reactions. The latter set is regularly used in petrochemical plants and oil refineries.

Unconventional oil reservoirs

Oil-eating bacteria biodegrades oil that has escaped to the surface. Oil sands are reservoirs of partially biodegraded oil still in the process of escaping and being biodegraded, but they contain so much migrating oil that, although most of it has escaped, vast amounts are still present—more than can be found in conventional oil reservoirs. The lighter fractions of the crude oil are destroyed first, resulting in reservoirs containing an extremely heavy form of crude oil, called crude bitumen in Canada, or extra-heavy crude oil in Venezuela. These two countries have the world's largest deposits of oil sands.

On the other hand, oil shales are source rocks that have not been exposed to heat or pressure long enough to convert their trapped hydrocarbons into crude oil. Technically speaking, oil shales are not really shales and do not really contain oil, but are usually relatively hard rocks called marls containing a waxy substance called kerogen. The kerogen trapped in the rock can be converted into crude oil using heat and pressure to simulate natural processes. The method has been known for centuries and was patented in 1694 under British Crown Patent No. 330 covering, "A way to extract and make great quantityes of pitch, tarr, and oyle out of a sort of stone." Although oil shales are found in many countries, the United States has the world's largest deposits.[16]


The petroleum industry generally classifies crude oil by the geographic location it is produced in (e.g. West Texas Intermediate, Brent, or Oman), its API gravity (an oil industry measure of density), and by its sulfur content. Crude oil may be considered light if it has low density or heavy if it has high density; and it may be referred to as sweet if it contains relatively little sulfur or sour if it contains substantial amounts of sulfur.

The geographic location is important because it affects transportation costs to the refinery. Light crude oil is more desirable than heavy oil since it produces a higher yield of gasoline, while sweet oil commands a higher price than sour oil because it has fewer environmental problems and requires less refining to meet sulfur standards imposed on fuels in consuming countries. Each crude oil has unique molecular characteristics which are understood by the use of crude oil assay analysis in petroleum laboratories.

Barrels from an area in which the crude oil's molecular characteristics have been determined and the oil has been classified are used as pricing references throughout the world. Some of the common reference crudes are:

There are declining amounts of these benchmark oils being produced each year, so other oils are more commonly what is actually delivered. While the reference price may be for West Texas Intermediate delivered at Cushing, the actual oil being traded may be a discounted Canadian heavy oil delivered at Hardisty, Alberta, and for a Brent Blend delivered at the Shetlands, it may be a Russian Export Blend delivered at the port of Primorsk.[17]

Petroleum industry

prices for West Texas Intermediate 1996 - 2009]]

The petroleum industry is involved in the global processes of exploration, extraction, refining, transporting (often with oil tankers and pipelines), and marketing petroleum products. The largest volume products of the industry are fuel oil and gasoline (petrol). Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics. The industry is usually divided into three major components: upstream, midstream and downstream. Midstream operations are usually included in the downstream category.

Petroleum is vital to many industries, and is of importance to the maintenance of industrialized civilization itself, and thus is critical concern to many nations. Oil accounts for a large percentage of the world’s energy consumption, ranging from a low of 32% for Europe and Asia, up to a high of 53% for the Middle East. Other geographic regions’ consumption patterns are as follows: South and Central America (44%), Africa (41%), and North America (40%). The world at large consumes 30 billion barrels (4.8 km³) of oil per year, and the top oil consumers largely consist of developed nations. In fact, 24% of the oil consumed in 2004 went to the United States alone [18], though by 2007 this had dropped to 21% of world oil consumed.[19]

In the US, in the states of Arizona, California, Hawaii, Nevada, Oregon and Washington, the Western States Petroleum Association (WSPA) is responsible for producing, distributing, refining, transporting and marketing petroleum. This is non-profit trade association that was founded in 1907, and is the oldest petroleum trade association in the United States.[20]


- creator of the process of refining of kerosene from crude oil.]]

, 1922]] , 1938.]] Petroleum, in one form or another, is not a recent discovery. More than four thousand years ago, according to Herodotus and confirmed by Diodorus Siculus, asphalt was employed in the construction of the walls and towers of Babylon; there were oil pits near Ardericca (near Babylon), and a pitch spring on Zacynthus.[21] Great quantities of it were found on the banks of the river Issus, one of the tributaries of the Euphrates. Ancient Persian tablets indicate the medicinal and lighting uses of petroleum in the upper levels of their society.

Oil was exploited in the Roman province of Dacia, now in Romania, where it was called picula.

The earliest known oil wells were drilled in China in 347 CE or earlier. They had depths of up to about 800 feet (240 m) and were drilled using bits attached to bamboo poles.[22] The oil was burned to evaporate brine and produce salt. By the 10th century, extensive bamboo pipelines connected oil wells with salt springs. The ancient records of China and Japan are said to contain many allusions to the use of natural gas for lighting and heating. Petroleum was known as burning water in Japan in the 7th century.[21] In his book Dream Pool Essays written in 1088, the polymathic scientist and statesman Shen Kuo of the Song Dynasty coined the word 石油 (Shíyóu, literally "rock oil") for petroleum, which remains the term used in contemporary Chinese.

The first streets of Baghdad were paved with tar, derived from petroleum that became accessible from natural fields in the region. In the 9th century, oil fields were exploited in the area around modern Baku, Azerbaijan, to produce naphtha. These fields were described by the Arab geographer Abu al-Hasan 'Alī al-Mas'ūdī in the 10th century, and by Marco Polo in the 13th century, who described the output of those wells as hundreds of shiploads. Petroleum was distilled by the Persian alchemist Muhammad ibn Zakarīya Rāzi (Rhazes) in the 9th century, producing chemicals such as kerosene in the alembic (al-ambiq),[23] and which was mainly used for kerosene lamps.[24] Arab and Persian chemists also distilled crude oil in order to produce flammable products for military purposes. Through Islamic Spain, distillation became available in Western Europe by the 12th century.[25] It has also been present in Romania since the 13th century, being recorded as păcură.[26]

The earliest mention of petroleum in the Americas occurs in Sir Walter Raleigh's account of the Trinidad Pitch Lake in 1595; whilst thirty-seven years later, the account of a visit of a Franciscan, Joseph de la Roche d'Allion, to the oil springs of New York was published in Sagard's Histoire du Canada. A Russian traveller, Peter Kalm, in his work on America published in 1748 showed on a map the oil springs of Pennsylvania.[21]

In 1710 or 1711 (sources vary) the Russian-born Swiss physician and Greek teacher Eyrini d’Eyrinis (also spelled as Eirini d'Eirinis) discovered asphaltum at Val-de-Travers, (Neuchâtel). He established a bitumen mine de la Presta there in 1719 that operated until 1986.[27][28][29][30]

Oil sands were mined from 1745 in Merkwiller-Pechelbronn, Alsace under the direction of Louis Pierre Ancillon de la Sablonnière, by special appointment of Louis XV.[31] The Pechelbronn oil field was active until 1970, and was the birth place of companies like Antar and Schlumberger. The first modern refinery was built there in 1857.[31]

The modern history of petroleum began in 1846 with the discovery of the process of refining kerosene from coal by Nova Scotian Abraham Pineo Gesner. Ignacy Łukasiewicz improved Gesner's method to develop a means of refining kerosene from the more readily available "rock oil" ("petr-oleum") seeps in 1852 and the first rock oil mine was built in Bóbrka, near Krosno in Galicia(Poland/Ukraine) in the following year. In 1854, Benjamin Silliman, a science professor at Yale University in New Haven, was the first to fractionate petroleum by distillation. These discoveries rapidly spread around the world, and Meerzoeff built the first Russian refinery in the mature oil fields at Baku in 1861. At that time Baku produced about 90% of the world's oil.

The first commercial oil well in Romania was drilled in 1857, and the world's first oil refinery opened at Ploiesti, Romania being the first country in the world with a crude oil output officially recorded in international statistics, namely 275 tonnes[32][33].

The first oil well in North America was in Oil Springs, Ontario, Canada in 1858, dug by James Miller Williams. The US petroleum industry began with Edwin Drake's drilling of a 69-foot (21 m) oil well in 1859, on Oil Creek near Titusville, Pennsylvania, for the Seneca Oil Company (originally yielding 25 barrels per day (4.0 m³/d), by the end of the year output was at the rate of 15 barrels per day (2.4 m³/d)). See also the Pennsylvanian oil rush The industry grew through the 1800s, driven by the demand for kerosene and oil lamps. It became a major national concern in the early part of the 20th century; the introduction of the internal combustion engine provided a demand that has largely sustained the industry to this day. Early "local" finds like those in Pennsylvania and Ontario were quickly outpaced by demand, leading to "oil booms" in Texas, Oklahoma, and California.

Early production of crude petroleum in the United States:[21]

  • 1859: 2,000 barrels (~270 t)
  • 1869: 4,215,000 barrels (~5.750×10^5 t)
  • 1879: 19,914,146 barrels (~2.717×10^6 t)
  • 1889: 35,163,513 barrels (~4.797×10^6 t)
  • 1899: 57,084,428 barrels (~7.788×10^6 t)
  • 1906: 126,493,936 barrels (~1.726×10^7 t)

By 1910, significant oil fields had been discovered in Canada (specifically, in the province of Alberta), the Dutch East Indies (1885, in Sumatra), Persia (1908, in Masjed Soleiman), (1863, in Zorritos District) Peru, Venezuela, and Mexico, and were being developed at an industrial level.

During World War II, oil facilities were a major strategic asset and were extensively bombed.

Even until the mid-1950s, coal was still the world's foremost fuel, but oil quickly took over. Following the 1973 energy crisis and the 1979 energy crisis, there was significant media coverage of oil supply levels. This brought to light the concern that oil is a limited resource that will eventually run out, at least as an economically viable energy source. At the time, the most common and popular predictions were quite dire. However, a period of increased production and reduced demand caused an oil glut in the 1980s.

Today, about 90% of vehicular fuel needs are met by oil. Petroleum also makes up 40% of total energy consumption in the United States, but is responsible for only 2% of electricity generation. Petroleum's worth as a portable, dense energy source powering the vast majority of vehicles and as the base of many industrial chemicals makes it one of the world's most important commodities. Access to it was a major factor in several military conflicts of the twentieth century, including World War II.[34] The top three oil producing countries are Saudi Arabia, Russia, and the United States.[35] About 80% of the world's readily accessible reserves are located in the Middle East, with 62.5% coming from the Arab 5: Saudi Arabia (12.5%), UAE, Iraq, Qatar and Kuwait. However, with high oil prices, (above $100/barrel) Venezuela has larger reserves than Saudi Arabia due to crude reserves derived from bitumen.

Price of petroleum

After the collapse of the OPEC-administered pricing system in 1985, and a short lived experiment with netback pricing, oil-exporting countries adopted a market-linked pricing mechanism. [36] First adopted by PEMEX in 1986, market-linked pricing received wide acceptance and by 1988 became and still is the main method for pricing crude oil in international trade.[36] The current reference, or pricing markers, are Brent, WTI , and Dubai/Oman. [36]


The chemical structure of petroleum is heterogeneous (composed of hydrocarbon chains of different lengths). Because of this, petroleum may be taken to oil refineries and the hydrocarbon chemicals separated by distillation and treated by other chemical processes, to be used for a variety of purposes. See Petroleum products.

in Los Angeles.]]


The most common distillations of petroleum are fuels. Fuels include:

Other derivatives

Certain types of resultant hydrocarbons may be mixed with other non-hydrocarbons, to create other end products:

Petroleum by country

Consumption statistics


This table orders the amount of petroleum consumed in 2006 in thousand barrels (bbl) per day and in thousand cubic metres (m3) per day:[1][2][3]

Consuming Nation 2006 (1000 bbl/day) (1000 m3/day) population in millions bbl/year per capita
United States 1 20,687.42 3,289.0 304 24.8
China 7,201.28 1,144.9 1369 1.9
Japan 2 5,197.70 826.4 128 14.8
Russia 1 2,810.76 446.9 142 7.2
Germany 2 2,691.81 428.0 82 12
India 2 2,571.90 408.9 1201 0.8
Canada 2,296.66 365.1 32[4] 26.5
Brazil 2,216.84 352.4 187 4.3
South Korea 2 2,179.90 346.6 49[5] 16.3
Saudi Arabia (OPEC) 2,139.42 340.1 27[6] 28.9
Mexico 1 2,077.51 330.3 107 7.1
France 21,981.18 315.0 61[7] 11.9
United Kingdom 1 1,812.01 288.1 61[8] 10.9
Italy 21,742.58 277.0 58[9] 10.9
Iran (OPEC)1,679.20 267.0 68[10] 8.9

Source: US Energy Information Administration

1 peak production of oil already passed in this state

2 This country is not a major oil producer



In petroleum industry parlance, production refers to the quantity of crude extracted from reserves, not the literal creation of the product.

# Producing Nation 103bbl/d (2006) 103bbl/d (2007)
1 Saudi Arabia (OPEC) 10,665 10,234
2 Russia 1 9,677 9,876
3 United States 1 8,331 8,481
4 Iran (OPEC) 4,148 4,043
5 China 3,845 3,901
6 Mexico 1 3,707 3,501
7 Canada 2 3,288 3,358
8 United Arab Emirates (OPEC) 2,945 2,948
9 Venezuela (OPEC) 1 2,803 2,667
10 Kuwait (OPEC) 2,675 2,613
11 Norway 1 2,786 2,565
12 Nigeria (OPEC) 2,443 2,352
13 Brazil 2,166 2,279
14 Algeria (OPEC) 2,122 2,173
15 Iraq (OPEC) 3 2,008 2,094
16 Libya (OPEC) 1,809 1,845
17 Angola (OPEC) 1,435 1,769
18 United Kingdom 1,689 1,690
19 Kazakhstan 1,388 1,445
20 Qatar (OPEC) 1,141 1,136
21 Indonesia 1,102 1,044
22 India 854 881
23 Azerbaijan 648 850
24 Argentina 802 791
25 Oman 743 714
26 Malaysia 729 703
27 Egypt 667 664
28 Australia 552 595
29 Colombia 544 543
30 Ecuador (OPEC) 536 512
31 Sudan 380 466
32 Syria 449 446
33 Equatorial Guinea 386 400
34 Yemen 377 361
35 Vietnam 362 352
36 Thailand 334 349
37 Denmark 344 314
38 Congo 247 250
39 Gabon 237 244
40 South Africa 204 199

Source: U.S. Energy Information Administration

1 Peak production of conventional oil already passed in this state

2 Although Canadian conventional oil production is declining, total oil production is increasing as oil sands production grows. If oil sands are included, it has the world's second largest oil reserves after Saudi Arabia.

3 Though still a member, Iraq has not been included in production figures since 1998


See also: Fossil fuel exporters

In order of net exports in 2006 in thousand bbl/d and thousand /d:

# Exporting Nation (2006) (103bbl/d) (103m3/d)
1 Saudi Arabia (OPEC) 8,651 1,376
2 Russia 1 6,565 1,044
3 Norway 1 2,542 404
4 Iran (OPEC) 2,519 401
5 United Arab Emirates (OPEC) 2,515 400
6 Venezuela (OPEC) 1 2,203 350
7 Kuwait (OPEC) 2,150 342
8 Nigeria (OPEC) 2,146 341
9 Algeria (OPEC) 1 1,847 297
10 Mexico 1 1,676 266
11 Libya (OPEC) 1 1,525 242
12 Iraq (OPEC) 1,438 229
13 Angola (OPEC) 1,363 217
14 Kazakhstan 1,114 177
15 Canada 2 1,071 170

Source: US Energy Information Administration

1 peak production already passed in this state

2 Canadian statistics are complicated by the fact it is both an importer and exporter of crude oil, and refines large amounts of oil for the U.S. market. It is the leading source of U.S. imports of oil and products, averaging 2.5 MMbbl/d in August 2007. [1].

Total world production/consumption (as of 2005) is approximately 84 million barrels per day (13,400,000 m³/d).

See also: Organization of Petroleum Exporting Countries.


In order of net imports in 2006 in thousand bbl/d and thousand /d:

# Importing Nation (2006) (103bbl/day) (103m3/day)
1 United States 1 12,220 1,943
2 Japan 5,097 810
3 China 2 3,438 547
4 Germany 2,483 395
5 South Korea 2,150 342
6 France 1,893 301
7 India 1,687 268
8 Italy 1,558 248
9 Spain 1,555 247
10 Republic of China (Taiwan) 942 150
11 Netherlands 936 149
12 Singapore 787 125
13 Thailand 606 96
14 Turkey 576 92
15 Belgium 546 87

Source: US Energy Information Administration

1 peak production of oil already passed in this state

2 Major oil producer whose production is still increasing

Non-producing consumers

Countries whose oil production is 10% or less of their consumption.

# Consuming Nation (bbl/day) (m³/day)
1 Japan 5,578,000 886,831
2 Germany 2,677,000 425,609
3 South Korea 2,061,000 327,673
4 France 2,060,000 327,514
5 Italy 1,874,000 297,942
6 Spain 1,537,000 244,363
7 Netherlands 946,700 150,513

Source : CIA World Factbook

Environmental effects

The presence of oil has significant social and environmental impacts, from accidents and routine activities such as seismic exploration, drilling, and generation of polluting wastes, greenhouse gases and climate change not produced by renewable energy.


Oil extraction is costly and sometimes environmentally damaging, although Dr. John Hunt of the Woods Hole Oceanographic Institution pointed out in a 1981 paper that over 70% of the reserves in the world are associated with visible macroseepages, and many oil fields are found due to natural seeps. Offshore exploration and extraction of oil disturbs the surrounding marine environment.[11] Extraction may involve dredging, which stirs up the seabed, killing the sea plants that marine creatures need to survive. But at the same time, offshore oil platforms also form micro-habitats for marine creatures.

Oil spills


Crude oil and refined fuel spills from tanker ship accidents have damaged natural ecosystems in Alaska, the Galapagos Islands, France and many other places.

The quantity of oil spilled during accidents has ranged from a few hundred tons to several hundred thousand tons (e.g., Atlantic Empress, Amoco Cadiz). Smaller spills have already proven to have a great impact on ecosystems, such as the Exxon Valdez oil spill

Oil spills at sea are generally much more damaging than those on land, since they can spread for hundreds of nautical miles in a thin oil slick which can cover beaches with a thin coating of oil. This can kill sea birds, mammals, shellfish and other organisms it coats. Oil spills on land are more readily containable if a makeshift earth dam can be rapidly bulldozed around the spill site before most of the oil escapes, and land animals can avoid the oil more easily.

Control of oil spills is difficult, requires ad hoc methods, and often a large amount of manpower (picture). The dropping of bombs and incendiary devices from aircraft on the Torrey Canyon wreck produced poor results;[12] modern techniques would include pumping the oil from the wreck, like in the Prestige oil spill or the Erika oil spill.[13]


James S. Robbins has argued that the advent of petroleum-refined kerosene saved some species of great whales from extinction by providing an inexpensive substitute for whale oil, thus eliminating the economic imperative for open-boat whaling.[14]

Alternatives to petroleum

In the United States in 2007 about 70% of petroleum was used for transportation (e.g. gasoline, diesel, jet fuel), 24% by industry (e.g. production of plastics), 5% for residential and commercial uses, and 2% for electricity production. [15] Outside of the US, a higher proportion of petroleum tends to be used for electricity. [16]

Alternatives to petroleum-based vehicle fuels

Alternative propulsion refers to both:

Currently, cars can be classified into the following groups:

Alternatives to using oil in industry

Biological feedstocks do exist for industrial uses such as plastic production. [18]

Alternatives to burning petroleum for electricity

In oil producing countries with little refinery capacity, oil is sometimes burned to produce electricity. Renewable energy technologies such as solar power, wind power, micro hydro, biomass and biofuels might someday be used to replace some of these generators, but today the primary alternatives remain large scale hydroelectricity, nuclear and coal-fired generation.

Future of petroleum production

The future of petroleum as a fuel remains somewhat controversial. USA Today news reported in 2004 that there were 40 years of petroleum left in the ground. Some argue that because the total amount of petroleum is finite, the dire predictions of the 1970s have merely been postponed. Others claim that technology will continue to allow for the production of cheap hydrocarbons and that the earth has vast sources of unconventional petroleum reserves in the form of tar sands, bitumen fields and oil shale that will allow for petroleum use to continue in the future. They argue that both the Canadian tar sands and United States oil shale deposits represent potential reserves with just as much oil as current liquid petroleum deposits.[19]

Hubbert peak theory

The Hubbert peak theory (also known as peak oil) posits that future petroleum production (whether for individual oil wells, entire oil fields, whole countries, or worldwide production) will eventually peak and then decline at a similar rate to the rate of increase before the peak as these reserves are exhausted. It also suggests a method to calculate the timing of this peak, based on past production rates, the observed peak of past discovery rates, and proven oil reserves. The peak of oil discoveries was in 1965, and oil production per year has surpassed oil discoveries every year since 1980.[20]

In 1956, M. King Hubbert correctly predicted US oil production would peak around 1971. When this occurred and the US began losing its excess production capacity, OPEC gained the ability to manipulate oil prices, leading to the 1973 and 1979 oil crises. Since then, most other countries have also peaked. China has confirmed that two of its largest producing regions are in decline, and Mexico's national oil company, Pemex, has announced that Cantarell Field, one of the world's largest offshore fields, was expected to peak in 2006, and then decline 14% per annum.

Controversy surrounds predictions of the timing of the global peak, as these predictions are dependent on the past production and discovery data used in the calculation as well as how unconventional reserves are considered. Supergiant fields have been discovered in the past decade, such as Azadegan, Carioca/Sugar Loaf, Tupi, Jupiter, Ferdows/Mounds/Zagheh, Tahe, Jidong Nanpu/Bohai Bay, West Kamchatka, and Kashagan, as well as tremendous reservoir growth from places like the Bakken and massive syncrude operations in Venezuela and Canada.[21] However, while past understanding of total oil reserves changed with newer scientific understanding of petroleum geology, current estimates of total oil reserves have been in general agreement since the 1960s. Further, predictions regarding the timing of the peak are highly dependent on the past production and discovery data used in the calculation.

It is difficult to predict the oil peak in any given region, due to the lack of transparency in accounting of global oil reserves.[22] Based on available production data, proponents have previously predicted the peak for the world to be in years 1989, 1995, or 1995-2000. Some of these predictions date from before the recession of the early 1980s, and the consequent reduction in global consumption, the effect of which was to delay the date of any peak by several years. Just as the 1971 U.S. peak in oil production was only clearly recognized after the fact, a peak in world production will be difficult to discern until production clearly drops off.

Writers covering the petroleum industry

See also

Energy portal
Energy portal


  1. ^ U.S. Energy Information Administration. Excel file RecentPetroleumConsumptionBarrelsperDay.xls from web page (direct link: "Table Posted: November 7, 2008"
  2. ^ From DSW-Datareport 2006 ("Deutsche Stiftung Weltbevölkerung")
  3. ^ One cubic metre of oil is equivalent to 6.28981077 barrels of oil
  4. ^ Beauchesne, Eric (2007-03-13). "We are 31,612,897". National Post. Retrieved on 2008-11-11. 
  5. ^ IndexMundi. South Korea Population - Demographics. "48,846,823" ... "July 2006 est." Retrieved 2008-11-11
  6. ^ Sources vary: 24,600,000 from "UNHCR / Refworld / The Worst of the Worst 2006 - Saudi Arabia". United Nations High Commissioner for Refugees. Retrieved on 2008-11-11. ; while IndexMundi listed a July 2006 estimate of 27,019,73: "Saudi Arabia Population - Demographics". IndexMundi. Retrieved on 2008-11-11. 
  7. ^ IndexMundi. France Population - Demographics. "60,876,136" ... "July 2006 est." Retrieved 2008-11-11
  8. ^ IndexMundi. United Kingdom Population - Demographics. "60,609,153" ... "July 2006 est." Retrieved 2008-11-11
  9. ^ IndexMundi. Italy Population - Demographics. "58,133,509" ... "July 2006 est." Retrieved 2008-11-11
  10. ^ IndexMundi. Iran Population - Demographics. "68,688,433" ... "July 2006 est." Retrieved 2008-11-11
  11. ^ Waste discharges during the offshore oil and gas activity by Stanislave Patin, tr. Elena Cascio
  12. ^ Torrey Canyon bombing by the Navy and RAF
  13. ^ Pumping of the Erika cargo
  14. ^ How Capitalism Saved the Whales by James S. Robbins, The Freeman, August, 1992.
  15. ^ "U.S. Primary Energy Consumption by Source and Sector, 2007". Energy Information Administration
  16. ^ needtitleUN Energy Program
  17. ^ Amory B. Lovins, E. Kyle Datta, Odd-Even Bustnes, Jonathan G. Koomey, Nathan J. Glasgow. "Winning the oil endgame" Rocky Mountain Institute
  18. ^ Bioprocessing Seattle Times (2003)
  19. ^ Lambertson, Giles (2008-02-16). "Oil Shale: Ready to Unlock the Rock". Construction Equipment Guide. Retrieved on 2008-05-21. 
  20. ^ Campbell CJ (2000-12). "Peak Oil Presentation at the Technical University of Clausthal]". 
  21. ^ NCPA - Policy Backgrounder 159 - Are We Running Out of Oil?
  22. ^ New study raises doubts about Saudi oil reserves

External links

Retrieved from ""


Up to date as of January 15, 2010

Definition from Wiktionary, a free dictionary



Wikipedia has an article on:



From Middle English petroleum from petra (rock) + oleum (oil).




petroleums or, rarely, petrolea

petroleum (plural petroleums or, rarely, petrolea)

  1. A flammable liquid ranging in color from clear to very dark brown and black, consisting mainly of hydrocarbons, occurring naturally in deposits under earth surface.


Derived terms


Simple English

Petroleum, also called crude oil, is a thick and black liquid. It consists mainly of hydrocarbons. It is mainly found in the Middle East, North America, and Russia. It is the most important world energy source. It supplies 38% of the world's energy at present.

Petroleum can be separated into less complex but more useful mixtures by fractional distillation. The process is called oil refining.

Petroleum can be easily transported by pipeline. Treated petroleum can be used as fuels; mainly gasoline (petrol) for cars, Diesel fuel for Diesel engines used in trucks, trains and ships, kerosene fuel for jets and as lubricants.

Other uses of petroleum:



Petroleum resource is limited and non-renewable. Most of it would run out within 70 years. Burning petroleum adds the carbon in the oil to the oxygen in the air to create carbon dioxide. The carbon can be removed from the carbon dioxide by plants.

Crude is chemically speaking a mixture of lots of different chemicals most of which burn well. It is separated by distillation in oil refineries to give separate chemicals such as gasoline (or petrol) for cars, kerosene for airplanes and bitumen for roads. The bitumen gives crude oil its dark black colour; most of the other chemicals in crude are slightly yellow or colourless.

There is a lot of crude oil left underground. Oil companies quote "reserves" which some people confuse with the actual amount of oil underground, but are more to do with extraction costs. Most of the crude left underground is in the Middle East which is not a politically stable part of the world. Some governments with lots of oil reserves work together through OPEC to keep production low and prices high. Policitians complain about high oil prices because voters complain. However many environmentalists worry about the damage being done by using oil as a fuel source (especially global warming) and are therefore happy that prices are kept high so that people use less oil.

Other pages

Other websites

Error creating thumbnail: sh: convert: command not found
Wikimedia Commons has images, video, and/or sound related to:


Got something to say? Make a comment.
Your name
Your email address