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Relying on Chalk

Almost all Danish oil and gas comes from the Central Graben. Nevertheless, there is still some interest in other areas, including the onshore.
This article appeared in Vol. 9, No. 3 - 2012

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Onshore as well as offshore exploration for oil and gas is taking place in Denmark. The first exploration licence in Denmark was granted in 1935. Following a series of failed attempts onshore, the first well in the Danish part of the North Sea discovered hydrocarbons in 1966. The discovery was also the first find in the North Sea, but it was not put on stream until 1996 (Kraka, with a cumulative production of more than 30 MMbo by the end of 2010). The first oil produced was from the Dan field, Denmark’s largest field, which is still producing some 50 Mbopd and by end 2010 had delivered a total of almost 640 MMbo.

Since 1983, areas in the North Sea have been offered to interested oil companies in a system of rounds; six in all, the latest in 2005/2006. However, in 1997, an Open Door procedure was introduced for all unlicensed areas east of 6° 15’ E, i.e. the entire Danish onshore and offshore areas with the exception of the westernmost part of the North Sea. However, to date no commercial oil or gas discoveries have been made in the Open Door area.

Denmark has 19 producing fields, of which 15 are operated by Mærsk Olie og Gas, three by DONG E&P and one by Hess Denmark. All of them are in the offshore sector, and most of them are located in the Central Graben, with only four in the Norwegian Danish Basin. The oil is, however, generated in the Central Graben.

All but five of the fields are producing from Danian and Upper Cretaceous chalk. This includes the largest producers like Dan, Gorm, Halfdan, Skjold and Tyra. Other producing formations are Paleocene sandstones east of the Central Graben (Siri, Nini and Cecilie), Lower Cretaceous shaly chalk and sandstones (Valdemar), Jurassic sandstones (Lulita) and Permian carbonates (Dagmar).

As of 1 January 2011, it was estimated that some 1.2 Bbo is left in the ground, while 2.3 Bbo have already been produced over almost 40 years. In 2010 oil production in Denmark averaged 245,000 bopd. About 0.6 Bboe of recoverable gas reserves remain, while about 1 Bboe of gas had been produced by the end of 2010. The recovery factor from all Danish gas fields averages 26%, although from the larger fields, like Dan, Gorm and Skjold, an average recovery factor of 37% is anticipated.

This means that Denmark will be a net exporter of oil and natural gas until 2019 and 2012, respectively.

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