Britain's Cairn Energy Plc has struck oil and gas in Rajasthan, the fourth discovery by the British firm, in the block which borders Gujarat.

"We have encountered hydrocarbons at RJ-Q-1 exploration well in Block RJ-ON-90/1 in Rajasthan," Bill Gammell, chief executive, Cairn Energy, said in New Delhi.

Previously, Cairn had found oil at Guda and Saraswati and oil and gas at Raageshwari in the same block, totalling over 30 million tonnes of oil and oil equivalent reserves.

A short drill stem test conducted on an interval from 3112 to 3174 metres in the deep Fatehgarh section flowed gas and condensate of 52 degrees API to surface prior to mechanical failure, while the shallow Thumbli section encountered a log-evaluated gross hydrocarbon interval of 250 metres in RJ-Q-1.

Cairn will suspend the well for additional testing of the deep Fatehgarh section using a service rig, while the shallow Thumbli will be tested in a second dedicated well.

The deep drilling rig is now moving to drill an exploration well on the GR-F prospect, which is also located on the Central Basin High about 40 km south of RJ-Q-1.

"I am delighted with our fourth exploration discovery in Rajasthan which further confirms the extensive distribution of hydrocarbons across the basin," Gammell said.

"Over the coming months we will be commencing exploration wells more than 120 km apart and we are confident of the potential for Rajasthan to become a new core producing area for Cairn."

Cairn holds 100 per cent interest in Block RJ-ON-90/1. The state-run Oil & Natural Gas Corporation has a right to 30 per cent of any development area resulting from a commercial discovery on the block.

The firm has also performed a second successful extended well test at Saraswati-1 discovery well. The well recovered oil at a rate of 1000 bpd for 14 days from the Barmer Hill interval. It had flowed for 13 days at an average rate of 470 barrels of oil per day from the Fatehgarh interval during an earlier test.