North Sea oil
North Sea oil is a mixture of hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

s, comprising liquid oil
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 and natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

, produced from oil reservoir
Oil reservoir
A petroleum reservoir, or oil and gas reservoir, is a subsurface pool of hydrocarbons contained in porous or fractured rock formations. The naturally occurring hydrocarbons, such as crude oil or natural gas, are trapped by overlying rock formations with lower permeability...

s beneath the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...


In the oil industry, the term "North Sea" often includes areas such as the Norwegian Sea and the area known as "West of Shetland", "the Atlantic Frontier" or "the Atlantic Margin" that is not geographically part of the North Sea.

Brent crude
Brent Crude
Brent Crude is the biggest of the many major classifications of crude oil consisting of Brent Crude, Brent Sweet Light Crude, Oseberg, Ekofisk, and Forties . Brent Crude is sourced from the North Sea. The Brent Crude oil marker is also known as Brent Blend, London Brent and Brent petroleum...

 is still used today as a standard benchmark for pricing oil, although the contract now refers to a blend of oils from fields in the northern North Sea.


Commercial extraction of oil on the shores of the North Sea dates back to 1851, when James Young retorted oil from torbanite
Torbanite, also known as boghead coal, is a variety of fine-grained black oil shale. It usually occurs as lenticular masses, often associated with deposits of Permian coals. Torbanite is classified as lacustrine type oil shale....

 (boghead coal, or oil shale) mined in the Midland Valley of Scotland. Across the sea in Germany, oil was found in the Wietze field near Hanover in 1859, leading to the discovery of 70 more fields, mostly in Lower Cretaceous and Jurassic reservoirs, producing a combined total of around 1340 m³ (8,400 barrels) per day.

Gas was found by chance in a water well near Hamburg in 1910, leading to minor gas discoveries in Zechstein
The Zechstein is a unit of sedimentary rock layers of Middle to Late Permian age located in the European Permian Basin which stretches from the east coast of England to northern Poland...

 dolomites elsewhere in Germany. In England, BP discovered gas in similar reservoirs in the Eskdale
-United Kingdom:*Eskdale, Cumbria, England*Eskdale, Dumfries and Galloway, Scotland*Eskdale, North Yorkshire, England*Eskdale , Cumberland, England, former constituency-United States:...

 anticline in 1938, and in 1939 they found commercial oil in Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...

 rocks at Eakring
Eakring is a village in the Newark and Sherwood district in Nottinghamshire.-Geography:It is situated between the A617 and the A616 roads between Ollerton and Southwell. Dukes Wood to the south is situated on the top of an escarpment, giving good views over the Trent valley to the east and towards...

 in Nottinghamshire
Nottinghamshire is a county in the East Midlands of England, bordering South Yorkshire to the north-west, Lincolnshire to the east, Leicestershire to the south, and Derbyshire to the west...

. Discoveries elsewhere in the East Midlands
East Midlands
The East Midlands is one of the regions of England, consisting of most of the eastern half of the traditional region of the Midlands. It encompasses the combined area of Nottinghamshire, Derbyshire, Leicestershire, Rutland, Northamptonshire and most of Lincolnshire...

 lifted production to 400 m³ (2,500 barrels) per day, and a second wave of exploration from 1953 to 1961 found the Gainsborough
-Places:* Gainsborough, Lincolnshire, England** Gainsborough Trinity F.C.** Gainsborough Riverside Festival** Gainsborough * Gainsborough, Saskatchewan, Canada* Gainsborough, New South Wales, Australia* Gainsborough, Ipswich, England...

 field and 10 smaller fields.

The Netherlands' first oil shows were seen in a drilling demonstration at De Mient during the 1938 World Petroleum Congress at The Hague. Subsequent exploration led to the 1943 discovery by Exploratie Nederland, part of the Royal Dutch/Shell company Bataafsche Petroleum Maatschappij, of oil under the Dutch village of Schoonebeek
Schoonebeek is a village in the Dutch province of Drenthe. It is located in the municipality of Emmen, about 12 km south of that city.Schoonebeek was a separate municipality from 1884 to 1998, when it merged with Emmen....

, near the German border. NAM found the Netherlands' first gas in Zechstein carbonates at Coevorden in 1948. 1952 saw the first exploration well in the province of Groningen, Haren-1, which was the first to penetrate the Lower Permian Rotliegendes sandstone that is the main reservoir for the gas fields of the southern North Sea, although in Haren-1 it contained only water. The Ten Boer well failed to reach target depth for technical reasons, but was completed as a minor gas producer from the Zechstein carbonates. The Slochteren-1 well found gas in the Rotliegendes in 1959, although the full extent of what became known as the Groningen field was not appreciated until 1963 - it is currently estimated at ~96 cu ft (2.718417312E-08 km³) recoverable gas reserves. Smaller discoveries to the west of Groningen followed.


The UK Continental Shelf Act came into force in May 1964. Seismic exploration and the first well followed later that year. It and a second well on the Mid North Sea High were dry, as the Rotliegendes was absent, but BP's Sea Gem
Sea Gem
The Sea Gem was the first British offshore oil rig, and the first British offshore rig disaster when in 1965, the rig's legs collapsed, killing 13 of the crew.-Background:...

rig struck gas in the West Sole field in September 1965. The celebrations were short-lived because the Sea Gem sank with the loss of 13 lives after part of the rig collapsed as it was moved away from the discovery well. Larger gas finds followed in 1966 - Leman Bank, Indefatigable and Hewett, but by 1968 companies had lost interest in further exploration of the British sector, a result of a ban on gas exports and low prices offered by the only buyer, British Gas. West Sole came onstream in May 1967. Licensing regulations for Dutch waters were not finalised until 1967.

The situation was transformed in December 1969, when Phillips Petroleum discovered oil in Chalk of Danian
The Danian is the oldest age or lowermost stage of the Paleocene epoch or series, the Paleogene period or system and the Cenozoic era or erathem. The beginning of the Danian age is at the Cretaceous-Tertiary extinction event...

 age at Ekofisk, in Norwegian waters in the central North Sea. The same month, Amoco discovered the Montrose field about 217 km (134.8 mi) east of Aberdeen. BP had been awarded several licences in the area in the second licensing round late in 1965, but had been reluctant to work on them. The discovery of Ekofisk prompted them to drill what turned out to be a dry hole in May 1970, followed by the discovery of the giant Forties oilfield
Forties oilfield
The Forties Oil Field is the largest oil field in the North Sea, 110 miles east of Aberdeen. It was discovered in 1970 and first produced oil in 1975 under ownership of BP.-History:...

 in October 1970. The following year, Shell Expro discovered the giant Brent oilfield
Brent oilfield
The Brent field is an oil field located in the East Shetland Basin north-east of Lerwick, Shetland Islands, Scotland at the water depth of . The field operated by Shell UK Limited was once one of the most productive parts of the UK's offshore assets but is now nearing the end of its useful...

 in the northern North Sea east of Shetland in Scotland.
Oil production started from the Argyll field (now Ardmore) in June 1975 followed by Forties in November of that year.
Volatile weather conditions in Europe's North Sea have made drilling particularly hazardous, claiming many lives. The conditions also make extraction a costly process; by the 1980s, costs for developing new methods and technologies to make the process both efficient and safe, far exceeded NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

's budget to land a man on the moon. The exploration of the North Sea has been a story of continually pushing the edges of the technology of exploitation (in terms of what can be produced) and later the technologies of discovery and evaluation (2-D seismic, followed by 3-D
Three-dimensional space
Three-dimensional space is a geometric 3-parameters model of the physical universe in which we live. These three dimensions are commonly called length, width, and depth , although any three directions can be chosen, provided that they do not lie in the same plane.In physics and mathematics, a...

 and 4-D seismic
In physics, spacetime is any mathematical model that combines space and time into a single continuum. Spacetime is usually interpreted with space as being three-dimensional and time playing the role of a fourth dimension that is of a different sort from the spatial dimensions...

; sub-salt seismic; immersive display and analysis suites and supercomputing to handle the flood of computation required).

The largest field discovered in the past 25 years is Buzzard also located off Scotland , found in June 2001 with producible reserves of almost 64×106 m³ (400m bbl) and an average output of 28 600 m³ to 30 200 m³ (180,000-190,000 bbl) per day. Most if not all of the UK oil fields are located in or just beside Scottish waters.


Following the 1958 Continental shelf convention and after some disputes on the rights to natural resource exploitation the national limits of the exclusive economic zone
Exclusive Economic Zone
Under the law of the sea, an exclusive economic zone is a seazone over which a state has special rights over the exploration and use of marine resources, including production of energy from water and wind. It stretches from the seaward edge of the state's territorial sea out to 200 nautical...

s were ratified.
Five countries are involved in oil production in North Sea. All operate a tax and royalty licensing regime. The respective sectors are divided by median lines agreed in the late 1960s:
  • United Kingdom
    United Kingdom
    The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

    - The Department of Energy and Climate Change
    Department of Energy and Climate Change
    The Department of Energy and Climate Change is a British government department created on 3 October 2008 by Prime Minister Gordon Brown to take over some of the functions of the Department for Business, Enterprise and Regulatory Reform and Department for Environment, Food and Rural Affairs...

     (DECC - formerly the Department of Trade and Industry) grants licences. The UKCS (United Kingdom Continental Shelf) is divided into quadrants of 1 degree latitude and one degree longitude. Each quadrant is divided into 30 blocks measuring 10 minutes of latitude and 12 minutes of longitude. Some blocks are divided further into part blocks where some areas are relinquished by previous licensees. For example, block 13/24a is located in quad 13 and is the 24th block and is the 'a' part block. The UK government has traditionally issued licences via periodic (now annual) licensing rounds. Blocks are awarded on the basis of the work programme bid by the participants. The UK government has actively solicited new entrants to the UKCS via "promote" licensing rounds with less demanding terms and the fallow acreage initiative, where non-active licences have to be relinquished.
  • Norway
    Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

    - The Norwegian Petroleum Directorate
    Norwegian Petroleum Directorate
    The Norwegian Petroleum Directorate or OD is a Norwegian government agency responsible for the regulation of the petroleum resources on the Norwegian continental shelf. Based in Stavanger it is to ensure that the petroleum resources are allocated in an optimal at the same time as they incur...

     (NPD Website in English ) grants licences. The NCS is also divided into quads of 1 degree by 1 degree. Norwegian licence blocks are larger than British blocks, being 15 minutes of latitude by 20 minutes of longitude (12 blocks in a quad). Like in Britain, there are numerous part blocks formed by re-licensing relinquished areas.
  • Denmark
    Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

    - The Danish Energy Authority (website in English) administers the Danish sector. The Danes also divide their sector of the North Sea into 1 degree by 1 degree quadrants. Their blocks, however, are 10 minutes latitude by 15 minutes longitude. Part blocks exist where partial relinquishments have taken place.
  • Germany
    Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

    - Germany and the Netherlands share a quadrant and block grid - quadrants are given letters rather than numbers. The blocks are 10 minutes latitude by 20 minutes longitude. Germany has the smallest sector in the North Sea.
  • Netherlands
    The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

    - The Dutch sector is located in the Southern Gas Basin and shares a grid pattern with Germany.

Reserves and production

The British and Norwegian sections hold most of the remainder of the large oil reserves. It is estimated that the Norwegian section alone contains 54% of the sea's oil reserves and 45% of its gas reserves.
More than half of the North Sea oil reserves have been extracted, according to official sources in both Norway and the UK. For Norway, the Norwegian Petroleum Directorate gives a figure of 4,601 million cubic metres of oil(corresponding to 29 billion barrels) for the Norwegian North Sea alone (excluding smaller reserves in Norwegian Sea and Barents Sea) ultimate of which 2,778 cubic metres (60%) has already been produced prior to January 2007. UK sources give a range of estimates of reserve, but even using the most optimistic "maximum" estimate of ultimate recovery, 76% had been recovered at end 2010. Note the UK figure includes fields which are not in the North Sea (onshore, West of Shetland).

United Kingdom Continental Shelf production was 137 million tonnes of oil and 105 billion m³ of gas in 1999. (1 tonne of crude oil converts to 7.5 barrels. The Danish explorations of Cenozoic stratigraphy, undertaken in the 1990s, showed petroleum rich reserves in the northern Danish sector, especially the Central Graben area. The Dutch area of the North Sea followed through with onshore and offshore gas exploration, and well creation.

Exact figures are debatable, because methods of estimating reserves vary and it is often difficult to forecast future discoveries.

Peaking in 1999, production of North Sea oil was nearly 950 000 m³ (6 million barrel
Barrel (unit)
A barrel is one of several units of volume, with dry barrels, fluid barrels , oil barrel, etc...

s) per day. Natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 production was nearly 280×109 m³ (10 trillion cubic feet) in 2001 and continues to increase, although British gas production is in sharp decline.

UK oil production has seen two peaks, in the mid 1980s and late 1990s, with a decline to around 300×103 m³ (1.9 million barrels) per day in the early 1990s. Monthly oil production peaked at 13.5×106 m³ (84.9 million barrels) in January 1985 although the highest annual production was seen in 1999, with offshore oil production in that year of 407×106 m³ (2559 million barrels) and had declined to 231×106 m³ (1452 million barrels) in 2007. This was the largest decrease of any other oil exporting nation in the world, and has led to Britain becoming a net importer of crude for the first time in decades, as recognized by the energy policy of the United Kingdom
Energy policy of the United Kingdom
The current energy policy of the United Kingdom is set out in the Energy White Paper of May 2007 and Low Carbon Transition Plan of July 2009, building on previous work including the 2003 Energy White Paper and the Energy Review Report in 2006...

. The production is expected to fall to one-third of its peak by 2020.

Carbon dioxide sequestration

In the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

, Norway's Statoil
Statoil ASA is a Norwegian petroleum company established in 1972. It merged with Norsk Hydro in 2007 and was known as StatoilHydro until 2009, when the name was changed back to Statoil ASA. The brand Statoil was retained as a chain of fuel stations owned by StatoilHydro...

 natural-gas platform Sleipner
Sleipnir is an eight-legged horse in Norse mythology. Sleipnir or Sleipner may also refer to:Ships and offshore* Sleipner gas field** Sleipner A, an offshore platform...

 strips carbon dioxide out of the natural gas with amine solvents and disposes of this carbon dioxide by geological sequestration. Sleipner reduces emissions of carbon dioxide by approximately one million tonnes a year. The cost of geological sequestration is minor relative to the overall running costs. As of April 2005, BP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...

 is considering a trial of large-scale sequestration of carbon dioxide stripped from power plant emissions in the Miller oilfield
Miller oilfield
The Miller oilfield is a deep reservoir under the North Sea, 240 kilometres northeast of Peterhead in UKCS Blocks 16/7b and 16/8b. It was discovered in 1982 by BP in a water depth of 100 metres. Production from Miller field started in June 1992, and plateau production was from late 1992 to 1997 at...

 as its reserves are depleted.

See also

  • Carbon sink
  • Category of Oil fields in Norway
  • Economy of Norway
    Economy of Norway
    The economy of Norway is a developed mixed economy with heavy state-ownership in strategic areas of the economy. Although sensitive to global business cycles, the economy of Norway has shown robust growth since the start of the industrial era...

  • Economy of Scotland
    Economy of Scotland
    The economy of Scotland is closely linked with the rest of the United Kingdom and the wider European Economic Area. Scotland has the second largest GVA per capita of countries in the United Kingdom after England, though it is still lower than the average of the United Kingdom as a whole...

  • Economy of the United Kingdom
    Economy of the United Kingdom
    The economy of the United Kingdom is the sixth-largest national economy in the world measured by nominal GDP and seventh-largest measured by purchasing power parity , and the third-largest in Europe measured by nominal GDP and second-largest measured by PPP...

  • Energy use and conservation in the United Kingdom
    Energy use and conservation in the United Kingdom
    Energy use in the United Kingdom stood at 3,894.6 kilogrammes of oil equivalent per capita in 2005 compared to a world average of 1,778.0. In 2008, total energy consumed was 9.85 exajoules - around 2% of the estimated 474 EJ worldwide total...

  • Geology of the United Kingdom
  • Geography of the United Kingdom
  • List of oil fields
  • Oil platform
    Oil platform
    An oil platform, also referred to as an offshore platform or, somewhat incorrectly, oil rig, is a lаrge structure with facilities to drill wells, to extract and process oil and natural gas, and to temporarily store product until it can be brought to shore for refining and marketing...

  • Subsea
    Subsea is a general term frequently used to refer to equipment, technology, and methods employed in marine biology, undersea geology, offshore oil and gas developments, underwater mining, and offshore wind power industries.- Oil and gas :...

  • United Kingdom Climate Change Programme
    United Kingdom Climate Change Programme
    The United Kingdom's Climate Change Programme was launched in November 2000 by the British government in response to its commitment agreed at the 1992 United Nations Conference on Environment and Development...

External links

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