Geology of the southern North Sea
The North Sea basin is located in northern Europe and lies between the United Kingdom, and Norway just north of The Netherlands and can be divided into many sub-basins. The Southern North Sea basin is the largest gas producing basin in the UK continental shelf, with production coming from the lower Permian sandstones which are sealed by the upper Zechstein salt.
Source: Wikipedia — Geology of the southern North Sea (CC BY-SA 4.0)