According to Oil and Gas Journal (OGJ), the UK had 3.1 billion barrels of proven crude oil reserves in 2010, the most of any EU member country. In 2009, the UK produced 1.5 million barrels per day (bbl/d) and consumed 1.7 million bbl/d of oil.

The UK Continental Shelf (UKCS), located in the North Sea off the eastern coast of the UK, contains the bulk of the country's oil reserves. There are also sizable reserves in the North Sea north and west of the Shetland Islands. Besides these offshore assets, the UK also has the Wytch Farm field located in the Wessex Basin, the largest onshore oil field in Europe, which has produced more than 400 million barrels of oil over its 35-year life.

Total oil production (including condensates, natural gas liquids, and refinery gain) in the UK was 1.5 million bbl/d in 2009, a 5-percent decline compared with the 2008 production levels. The 2009 production was about one half of the peak annual production in 1999. The UK government expects oil production in the country to continue to decline, reaching between 0.8 and 1.2 million bbl/d by 2015. Reasons for this decline include 1) the overall maturity of the country’s oil fields, 2) the application of new crude oil extraction technologies that accelerate field exhaustion, and 3) increasing costs as production shifts to more remote and inhospitable regions.

Most of the UK crude oil grades are light (30° to 40° API) and sweet (relatively small amounts of sulfur), which generally makes them attractive to foreign buyers. The UK was a net exporter of crude oil between 1981 and 2005 and has since become a net importer. According to the British Revenue and Customs Trade Statistics, about 69 percent of all crude oil imports originated in Norway (which is not part of EU 27) with another 8 percent arriving from Russia. Nonetheless, the UK also continues to export a significant amount of crude oil. In 2009, the country exported 875,000 bbl/d, with crude oil going to the Netherlands (40 percent), United States (24 percent), and Germany (17 percent). The remaining 19 percent of crude oil exports were sent to a number of other countries, including France, Spain, Canada, and Chile.

Source: UK HM Revenue and Customs

There is an extensive network of pipelines in the UK to carry oil extracted from North Sea platforms to coastal terminals in Scotland and northern England. BP operates the 110-mile, 36-inch Forties-Cruden Bay pipeline, linking fields in the Forties system to the oil terminal at Cruden Bay, Scotland. The company also operates a 110-mile, 36-inch pipeline connecting the Ninnian system to the Sullom Voe oil terminal on Shetland Island. Britoil Plc operates a 150-mile, 24-inch pipeline linking the Bruce and Forties fields to Cruden Bay and Talisman operates a 130-mile, 30-inch pipeline connecting the Piper system with Flotta on Orkney Island. Shell and Esso jointly operate a 93-mile, 36-inch connection between the Cormorant oil field and Sullom Voe. There are also numerous, small pipelines that connect each North Sea oil platform to these major backbones. Finally, the UK does have a few onshore crude oil pipelines, including a 90-mile, underground pipeline operated by BP that links the Wytch Farm field to the refinery at Fawley and the nearby oil export terminal at Southampton.

The UK has a single international crude oil pipeline, the 220-mile, 34-inch Norpipe operated by ConocoPhillips. With a capacity of 900,000 bbl/d, Norpipe connects Norwegian oil fields in the Ekofisk system to the oil terminal and refinery at Teesside.

The UK had 1.9 million bbl/d of refining capacity in 2010, according to OGJ. ExxonMobil operates the single-largest refinery in the country, the 329,500-bbl/d Fawley facility in southern England. Other companies with sizeable refining capacity in the UK include Shell (272,000 bbl/d), Petroplus (272,000 bbl/d), ConocoPhillips (221,000 bbl/d) and Total (221,000 bbl/d).

BP is the largest oil producer in the UK, with 23 fields producing a total of 247,000 bbl/d for the 12 months ending April 2010, according to the British Department of Energy and Climate Change (DECC). Other large oil producers in the UK include Nexen, Shell, and Total. The Canada-based Nexen operates Buzzard, UK’s largest oil field, which accounted for close to 15 percent of total UK oil production in 2009.

As UK oil fields mature, the industry has shifted focus from discovering new reserves to increasing the productivity of existing fields and developing smaller fields that were previously considered non-commercial. This trend has prompted oil majors such as BP and Shell to begin selling their UK assets in order to focus on high growth, international opportunities. The result has been the entry into the UK oil sector of many smaller operators. In 2003, U.S.-based Apache purchased BP's Forties field for $630 million, and other smaller operators, such as Talisman and Nexen have acquired significant production assets in the country. For the 12 months ending April 2010, five of the top ten producers (by volume of oil produced) were smaller operators.