Why oil will hit $100 a barrel: "The era of easy oil is over, but growing demand from countries like India and China is forcing oil firms to enter unusual territory.

Mike Watts is a man of deep convictions. For years he was convinced that there was oil in large quantities deep beneath the sand of the Rajasthan deserts in Western India.

Few other people in the industry agreed with him.

Mike's company - Cairn Energy - was in partnership with the Anglo-Dutch giant Shell to explore the area.

Eventually, after some discouraging early forays, Cairn paid Shell £7m to buy Shell out of the project.

Then, just over two years ago, it struck oil in a big way.

The find was big enough to propel Cairn from a small exploration business to a company with a value of nearly £3bn.

No big finds anymore

Enough to make a difference in an impoverished region of India. But not enough to alter the balance of supply and demand in the world.

'The easy oil has already been found,' explains Mike Watts on a sandy hilltop overlooking the Mangala discovery well which made his company's fortune. Oil companies are having to look much harder for major new oil finds.

And while some new finds are being made, like Cairn's in Rajasthan, few people in the oil industry believe that new discoveries will match the vast o"