State owned Oil and Natural Gas Commission – ONGC says, it has made a huge oil discovery off the West coast. In a statement today , ONGC said the new discovery was made in the currently producing D1 oilfield. The find will catapult D1 to become the third largest field in western offshore after prolific Mumbai High and Heera.D1 is currently producing 12,500 barrels per day and its out put could go up to 60,000 or three million tonnes a year. It is situated about 200 km 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 the year 1976.