State owned ONGC has made a huge oil discovery off the West coast. In a statement in New Delhi, the ONGC said the new discovery was made in the currently producing D1 oilfield. The find will make D1 to become the third largest field in western offshore after the Mumbai High and Heera offshore oil fields. D1 is currently producing 12,500 barrels per day and its out put could go up to 60,000 barrels per day or three million tonnes a year. It is situated about 200 kms west of Mumbai city in deep continental shelf at a water depth of 85 to 90 metres. The first well in D1-4 block was drilled in 1976. ONGC Chairman Sudhir Vasudeva said the company will sign a Memorandum of Understanding with the Mitsui Corporation of Japan to undertake downstreem operations.