The Kinsale Head, Ballycotton, Seven Heads and Southwest Kinsale Gas Fields lie approximately 50 kilometres off the south coast of Cork. The gas bearing reservoirs are in layers of porous sandstone rock about 750m below the seabed. These rock layers are relatively thin – about 120 meters, but they cover a large area – the main Kinsale Head reservoir, for example extends over 100 square kilometres. The rocks were formed in the Cretaceous geological era – around 100 million years ago and the gas is contained in the sandstone under layers of shale and chalk, which are impermeable to gas.
The gas found in the Kinsale Head area is exceptionally pure, consisting mainly of methane, and only requires removal of associated water to ensure it meets the required quality levels.
This conditioning is carried out offshore and the gas is then compressed to raise its pressure for transport to the Kinsale Energy Inch Terminal near Midleton, Co. Cork. From the Inch Terminal, the gas is then metered and transferred to Bord Gáis Éireann (BGÉ) for distribution nationwide.