Oil and Natural Gas Corporation has found some 600-700 billion cubic feet of natural gas reserves in Rajasthan's Chinnewala Tibba, bordering Pakistan, company sources said.

Testing indicates presence of sweet gas with more than 7000 kilo-calories per cubic metre calorific value, against usual range of 1250 to 3100 kilo-calories per cubic metre in other gas finds in Rajasthan.

"The one well we have drilled so far has flowed 3.5 million standard cubic metres per day of gas. We are delineating the area and another well would be drilled this year to establish the exact recoverable reserves," they said.

Prior to this, Cairn Energy of UK had struck oil in RJ-ON-90/1 block, bordering Gujarat, with preliminary estimate putting the reserves at 155 million barrels. Earlier it had made Saraswati and Guda discoveries in the same block with inplace reserves of about 25 million barrels per day.

Besides the Rajasthan discovery, ONGC in recent times has made six discoveries, at Vasai West (oil & gas) in western offshore, GS-49 (gas) and GS-KW (oil & gas) in Krishna Godavari offshore, Laipling-Gaon (oil & gas) and Banamali (oil), both in Assam.

The discoveries at Vasai West and Laipling-Gaon are particularly interesting; even by preliminary estimates, 240 million barrels of in-place oil plus oil-equivalent gas are available at Vasai West, and 100 million barrels, at Laipling-Gaon.