Hydrocarbon exploration is ongoing following the first major find at the Kinsale Head gas field off Cork in the mid @-@ 1970s . In 1999 , economically significant finds of natural gas was made in the Corrib Gas Field off the County Mayo coast . This have increased activity off the west coast in parallel with the " West of Shetland " step @-@ out development from the North Sea hydrocarbon province . The Helvick oil field , estimated to contain over 28 million barrels ( 4 @,@ 500 @,@ 000 m3 ) of oil , is another recent discovery .