Exploration for offshore oil & gas began in Ireland during the early 1970’s. The Kinsale Head Gas Field was discovered in 1971 by the US Company Marathon Oil Corporation. The field which is 50 kilometres off the coast of Co. Cork, in 90 meters water depth is still the largest single hydrocarbon discovery in Ireland, and PSE Kinsale Energy Limited is currently the only company producing natural gas from Irish offshore waters.
The natural gas in Kinsale Head is located in reservoirs some 3,000 feet (915 metres) beneath the floor of the Celtic Sea, and is produced to surface through two fixed steel production platforms, Alpha and Bravo, which were installed in 1977. Production began in 1978, initially supplying gas to the power station at Aghada and subsequently to the entire country.
Peak production occurred in 1995 at 99 bcf per year. The field is now in the decline phase and current annual production is 8 bcf per year.
A number of satellite gas fields were discovered and tied back to the platforms through 1990-2003, including:
• Ballycotton in 1991
• Southwest Kinsale in 1999
• Seven Heads in 2003 (developed by Ramco Energy)
Gas from satellite fields such as Ballycotton is produced using subsea well technology, whereby the wellheads are on the sea-floor and controlled remotely from one of the main production platforms. These satellite fields may be very long distances from the platforms, such as Seven Heads, which is 35km southwest of Kinsale Head
Gas from all of the offshore fields is combined, compressed and piped from the Alpha platform to Inch Terminal near Midleton, Co. Cork. From Inch Terminal, the gas is then metered and transferred to Bord Gáis Éireann (BGÉ) for distribution nationwide.
The Southwest Kinsale Field has now been redeveloped as Ireland’s first offshore gas storage facility and was licensed by the Commission for Energy Regulation in 2006.
The company was acquired by PETRONAS in 2009, following a decision by Marathon Oil Corporation to exit the Irish market. PETRONAS is a major Fortune 500 oil and gas company, with extensive world-wide gas and LNG operations.