The Altmark region has a long tradition in providing energy. The search for hydrocarbons began as early as in the 1920s of the last century. The well "Landesvater 1" was drilled in Dambeck in 1927. At that time it was the deepest oil well in Germany with a final depth of 1,800 meters. The search for oil was not successful at this early stage. The situation changed in the sixties when natural gas was found in the Altmark for the first time. The industrial extraction of natural gas started 17 August 1969 under the management of the then Kombinat Erdöl Erdgas Gommern.
The Altmark gas field is second on the Western European mainland after the Groningen field. It covers an area of more than 1,000 km2 (Fig. 1).
Fig. 1: Location of the Altmark gas field. Gas fields are marked red, oil fields green and underground saline structures light blue. The Altmark field is the second largest onshore natural gas field in Europe. Source: LBEG Lower Saxony
The natural gas is found in the geological formation "Rotliegendes" in a depth of approx. 3,500 meters. Initially, approx. 260 billion cubic meters of natural gas were deep underground. Today, approx. 80 per cent have been extracted. More than 450 wells have been drilled of which approx. one third is still in operation. The initial reservoir pressure was 425 bar, today it averages approx. 85 bar.
Gas production peaked in
the mid-eighties with an annual production of approx. twelve billion m3
(Fig. 2). At that time it was possible, on the average, to cover 36 per cent of
the natural gas consumption of the GDR. Due to natural depletion of the field
and falling reservoir pressure the annual production rate decreased to 500
million m3 until to date. The Altmark gas production facility has
been owned by the GDF SUEZ E&P Group since 1994.
Fig. 2: Annual natural gas production rate in the Altmark field from 1969 to 2006 (in billion m³).