North Sea Oil - Reserves and Production

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) of which 2,778 million cubic metres (60%) has already been produced prior to January 2007. UK sources give a range of estimates of reserves, 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 barrels) per day. Natural gas 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 (398 million barrels) and had declined to 231×106 m³ (220 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. The production is expected to fall to one-third of its peak by 2020.