The story of oil exploration in India began in dense jungles of Assam in the extreme northeast corner of India. Oil was struck at Makum near Margherita in Assam in 1867 just nine years after the historical Drake well in Pennsylvania in 1859. First commercial oil was discovered in Digboi in 1889. However, exploration and production started in a systematic way in 1899 after the Assam Oil Company (AOC) was formed.

After India attained independence in 1947, Geological Survey of India carried out extensive reconnaissance surveys and mapping to locate structures suitable for exploration of oil and gas. The real thrust to petroleum exploration in country was achieved only after the setting up of Oil and Natural Gas Commission (ONGC) in 1955. The first gas and oil pool were discovered in Jwalamukhi (Punjab) and Cambay (Gujarat) in 1958 respectively and in the same year Oil India Limited (OIL) was setup. The two public sectors companies, ONGC and OIL have discovered over 260 oil and gas fields located in Assam. Bombay Offshore Cambay, Cauvery, Krishna-Godavari, Tripura-Cachar, and West Rajasthan basins.

The indigenous oil production increased at a modest level during the 1970’s. The discovery of giant Bombay High field in 1974 in west coast offshore is the most significant event in India’s upstream petroleum sector, providing a big boost to its oil and gas production.

Government of India (GOI) offered acreages for exploration in 1980, 1982 and 1986 but the response was not encouraging. The government of India further liberalized the petroleum exploitation and exploration policy in 1991 inviting private companies, both overseas and indigenous, to participate in exploration in oil and gas field development activities to meet the ever-increasing national demand for oil and gas. A more attractive policy was formulated by the Government in 1999 and designated as the New Exploration Licensing Policy (NELP). Since 1980, eight exploration rounds, one round for joint venture and six rounds under NELP have been offered for global bidding. In order to introduce new technology and oil production, the GOI offered 69 small and medium sized oil and gas fields in onshore and offshore to private sector in 1992 and 1993.

The Government of India signed Production Sharing Contracts (PSCs) for 28 exploration blocks under Pre-NELP rounds since 1993. Out of these 12 blocks have been relinquished / surrendered. At present, 12 exploration blocks are under operation and 4 block are awaited for approval of additional exploration

Under the first round of New Exploration Licensing Policy, Government of India invited bids on 8th January 1999 for 48 blocks for exploration of oil and natural gas. Of these, 12 blocks were deepwater (beyond 400m isobath), 26 shallow offshore and 10 were onland blocks. The PSC's were signed for 24 exploration blocks comprising of 7 deepwater, 16 shallow offshore and 1 onland block. Since then, a total of 37 discoveries have been made in three KG and one Mahandi deepwater blocks and one shallow offshore block of Mahanadi –NEC.

Under the second round of New Exploration Licensing Policy, Government of India invited bids on 15th December 2000 for 25 blocks for exploration of oil and natural gas. Of these, 8 blocks were deepwater (beyond 400m isobath), 8 shallow offshore and 9 were onland blocks. The PSC’s were signed for 23 exploration blocks comprising 8 deepwater, 8 shallow offshore and 7 onland. At prsent 10 exploration blocks are under operation and 13 blocks have been relinquished.

A total of 5 discoveries have been made in four blocks viz. CB-ONN-2000/1 & CB-ONN-2000/2 located in Cambay basin, MN-OSN-2000/2 in Mahanadi basin & GS-OSN-2000/1 in GUJARAT-SAURASHTRA basin..

Under the third round of New Exploration Licensing Policy, Government of India invited bids on 27th March 2002 for 27 blocks for exploration of oil and natural gas. Of these, 9 blocks were deepwater (beyond 400m isobath), 7 shallow offshore and 11 were onland blocks. The PSC’s were signed for 23 exploration blocks comprising 9 deepwater, 6 shallow offshore and 8 onland. A total of 10 discoveries have been made in three blocks viz. KG-OSN-2001/1 ,KG-OSN-2001/2 & KG-OSN-2001/3 located in KG basin and CY-DWN-2001/2 in Cauvery basin..

Under the Fourth round of New Exploration Licensing Policy, Government of India invited bids on 8th May 2003 for 24 blocks for exploration of oil and natural gas. Of these, 12 blocks were deepwater (beyond 400m isobath), 1 shallow offshore and 11 were onland blocks. The PSC’s were signed for 20 exploration blocks comprising 10 deepwater and 10 onland. At present 19 exploration blocks are operating, comprising 9 deepwater and 10 onland. A total of 5 discoveries have been made in two Cambay onland blocks and one Cauvery blocks.

Under the fifth round of New Exploration Licensing Policy twenty exploration blocks have been awarded to different consortiums/ individual company. A total of two discoveries have been made a KG deepwater block.

Fifty five exploration blocks were offered under the sixth round on 23rd February, 2006, the highest offering so far under NELP, covering an area of 3.52 lakhs Sq.Km. in order to enhance country’s energy security. Government of India has received 165 bids for 52 blocks by bid closing date. Three deepwater blocks namely KK-DWN-2004/2, KK-DWN-2004/3 and AN-DWN-2004/1 have not received any bid. A total of 68 companies including 36 foreign companies and 32 Indian companies have submitted bids either on their own or as joint venture. The PSC’s were signed for 52 exploration blocks comprising 21 deepwater, 6 shallow water and 25 onland. The exploration activities are going on in all the 20 awarded blocks.

Fifty-seven exploration blocks were offered under the seventh round, proposed bid closing date is 30th June.