Assam was the starting point from where the oil industry in India took to its wing way back in the 19th century. Several oil seepages were observed in the districts of upper Assam making quite a number of people to start drilling. Although these attempts met with mixed success, it was in 1889 when well no.1 at Naharkatiya yielded oil to make production commercially viable. In 1899, the Assam oil company was formed to take up the oil interest in the Digboi-Makum area and in the same year Asia's first oil refinery, the Digboi refinery was established with capacity to refine nearly 500 barrels of oil a day. Since that time, Assam has moved from strength to strength in exploring, producing and refining the blackgold that the world calls petroleum. Today Assam accounts for 15% of India's crude output which is 50% of India's entire onshore production of oil and natural gas. Exploration and production giants like ONGC and Oil India limited have been operating in Assam successfully through its various oil fields. Assam also has the highest number of refineries in the country - a testimony to the amount of oil produced by this one state alone. The Digboi refinery, which started commercial production in 1901, now belongs to Indian Oil Corporation limited (Assam oil division) and has a refining capacity of 0.65 MMTPA of petrol, kerosene, diesel and other petroleum products. In 1962, Guwahati refinery was set up at Noonmati, Guwahati, also owned by the Indian Oil Corporation limited. It produces 3.00 MMTPA of liquefied petroleum gas (LPG), petrol, kerosene, diesel, furnace oil coke etc. The third refinery in the state was established at Dhaligoan near Bongaigaon in 1962.With a production of 2.35 MMTPA, it is known as Bongaigaon refinery and petro-chemicals limited (BRPL). Finally a fourth refinery in Assam was established at Numaligarh in Golaghat district in 1999, with a refining capacity of 3 million tonnes of oil and other products. Apart from these, a gas cracker unit and an integrated petrochemical complex are also coming up in the state. The HDPE/LLDPE is 220,000 TPA, polypropelene is 60,000 TPA. In the last 4 years or so, private sector/JV companies have made about 32 significant hydrocarbon discoveries in the state.
In the oil exploration and production sector, the major players in Assam are Oil India limited (OIL) and Oil and Natural Gas Corporation Limited (ONGC) operating as Assam Asset, ONGC today has 51 installations spread over 15 oilfields. In addition they boast of a network on 230 kms of trunk pipelines and 2000 kms of flow lines. Over the last five years the company has produced 7.28 MMT of oil and gas equivalent from its oilfields in Assam.
Oil India limited, with its field headquarters in Duliajan, has a majority of its 1 lakh sq.km. of oilfields in the North East.With a huge experience of E&P activities in the logistically difficult region, Oil India Ltd. utilizes state-of-the-art technology for 2D and 3D seismic studies. Experienced in drilling over 1250 wells, OIL is the major E & P player in Assam with a production of 3 MTPA of crude, 5 MMSCMD of gas and 50,000 tonnes of LPG per year. It also boasts of a 1157 kms fully automated crude oil pipeline that transport crude from its fields in Upper Assam to public sector refineries at Numaligarh, Guwahati, Bongaigaon and Barauni.