Science, Medicine and Technology

Solving the Chalk Mystery

07-2-2009 • arclein

In 1984, it was revealed that the North Sea oil field Ekofisk, situated 70 metres below sea level, had subsided by 1-2 metres. This was not the first time in history that a reservoir had compacted as a result of oil and gas extraction. But the scale of the seabed subsidence was unprecedented. The explanation to this phenomenon lay in the specific rock formation in this particular field. The Ekofisk rock reservoir is mainly made of chalk, as is the neighbouring Valhall field