According to a release on the company website, its three largest discoveries in Rajasthan - Mangala, Bhagyam and Aishwariya - had been certified as having 1.7 billion barrels of proven and probable oil in place.
Bill Gammell, chief executive of Cairn, said, "Rajasthan remains the catalyst for Cairn's continued growth in South Asia. We have, to date, found more than 2.5 billion barrels of oil in place in Rajasthan. While we move from discovery towards development and future production on the core fields, we are still exploring and appraising key parts of the block that show clear growth potential."
"Cairn has created a world-class strategic position in South Asia, and looks forward to an increasing resource and production base at a time when oil prices and interest in India have never been higher, he added."
Cairn said the gross life of the three fields' proved and probable reserves, including that recovered using enhanced oil techniques, had been upgraded to between 514 to 685 million barrels.
The crude is to be purchased by appointed nominee Mangalore Refineries and Petrochemicals, a subsidiary of Oil and Natural Gas Corporation.