Oil India is fundamentally a hydrocarbons company that has spent six decades turning a single oil discovery in Assam into a fully integrated energy enterprise - it finds and produces oil and gas, pipes it, refines it, and is now using the cash flows from that chain to build a green-energy business. It was born in 1959 to develop the Moran and Naharkatiya fields, became wholly government-owned in 1981, and transformed decisively in 2021 by buying a majority stake in Numaligarh Refinery, stitching upstream production to downstream refining for the first time. The recurring approach is to own the entire value chain in its home territory of Northeast India - from the wellhead to the petrol pump and the city-gas pipe - while using its balance-sheet strength to place long-dated bets on exploration frontiers and new energy.
Business segments
Five engines at different stages - a hydrocarbon cash cow, two consumer platforms at national scale, and a green-energy bet under construction - each built with the cash flows of the one before.
1. Upstream exploration and production: the foundation that feeds everything else
Finding and pumping oil and gas from 63 blocks across India, plus producing assets in Russia and Venezuela, generates the raw molecules that flow into the company's own pipelines and refineries.
- Production splits almost evenly between oil and gas - in FY26 the company produced 6.64 million metric tonnes of oil equivalent, with natural gas contributing almost half of that barrel-equivalent total, which lowers the carbon intensity of the portfolio and lifts margins. Daily crude output hit a ten-year high of 10,566 metric tonnes during the year.
- It sells gas directly, not through an intermediary - OIL bypasses the national gas grid operator and sells its entire gas output straight to customers such as power plants, fertiliser makers, and the Brahmaputra Cracker and Polymer plant, which means it captures the full price rather than sharing it with a middleman.
- Old fields get new life from specialist techniques - in Rajasthan's Baghewala field, where the oil is heavy and viscous, the company uses Cyclic Steam Stimulation (injecting steam to make the oil flow); 38 cycles have been run so far, and treated wells produced 39.5% more oil afterwards. Two fields are now under Production Enhancement Contracts, with more tenders planned.
- The exploration pipeline is delivering - eight discoveries in the last three years include the first-ever hydrocarbons on the North Bank of the Brahmaputra in Assam, a gas find in Rajasthan's shallow Sanu Formation, and natural gas confirmed in two of three exploratory wells drilled off the Andaman Islands.
2. Refining: where crude becomes cash
Numaligarh Refinery, in which OIL holds a 69.6% stake, turns crude oil into diesel, petrol and other products - and it does so with a structural cost advantage over coastal refineries.
- It runs on cheaper crude - the refinery is configured to process lower-cost grades of oil, giving it a built-in advantage of $2 to $4 per barrel compared with refineries that need pricier light-sweet crude. On top of that, it enjoys a 50% excise-duty benefit because it is located in the Northeast.
- The plant is being tripled in size - a massive expansion from 3 million tonnes per year to 9 million tonnes per year is underway, with the crude distillation unit and vacuum distillation unit - the "mother units" - beginning commissioning at the end of 2025. A 360,000-tonne-per-year polypropylene unit is being added alongside, which will push the refinery's Petrochemical Intensity Index to 3.88%.
- Output is already spoken for - NRL has offtake agreements with the three state-owned fuel retailers (BPCL, HPCL and IOCL) and sells directly to industrial buyers including ONGC, NALCO and HINDALCO, so its product does not sit in tanks waiting for a buyer. The Indo-Bangladesh Friendship Pipeline also provides an export route for diesel.
- It ran flat-out last year - the refinery processed 3.11 million tonnes of crude in FY26, its highest ever, at 103.75% of nameplate capacity, with a distillate yield of 87.25% - meaning it squeezed more high-value products out of each barrel than ever before.
3. Pipeline transportation: the toll road that ties the system together
A 2,500-kilometre-plus network of crude, gas and product pipelines moves molecules from Assam's oilfields to refineries and from refineries to markets, earning a fee on every unit that flows.
- The crude pipeline is a six-decade workhorse - the 1,157-km trunk line from Naharkatia to Barauni has been pumping continuously for over sixty years, crossing 78 rivers including the Brahmaputra, and in FY25 it carried a record 7.145 million tonnes of crude, including ONGC's oil and imported crude for the Bongaigaon refinery.
- The product pipeline just got a capacity upgrade - the Numaligarh-Siliguri line, which moves diesel and petrol from the refinery to markets in the east, was expanded from 1.72 million tonnes per year to 5.5 million tonnes per year, with mechanical completion in October 2025 and inauguration by the Prime Minister in March 2026.
- The gas pipeline is being readied for a hook-up - the Duliajan-Numaligarh gas pipeline is being expanded from 1.2 million standard cubic metres per day to 2.5 million, and once the common-carrier licence is secured, it will connect to the Indradhanush Gas Grid, opening up the national gas market to OIL's Assam production.
- A new crude artery is almost built - the Paradip-Numaligarh Crude Pipeline, which will supply imported crude to the expanded refinery, was 92% physically complete as of April 2026, with welding 97% done across its 1,626-km route.
4. Gas marketing and city-gas distribution: the retail face of the molecule business
OIL sells gas directly to industrial customers and, through a web of joint ventures, is building a consumer gas business with 81 CNG stations and over 73,000 household connections.
- Industrial offtake anchors the gas book - bulk consumers such as the Brahmaputra Cracker and Polymer plant and the Assam Gas Company (which supplies close to 650 tea gardens) take large volumes, while power and fertiliser plants provide baseload demand.
- City-gas JVs spread the geographic reach - through HPOIL Gas (a 50:50 partnership with HPCL), OIL operates 30 CNG stations and 21,005 piped-gas connections in Ambala-Kurukshetra, and another 29 CNG stations and 38,914 connections in Kolhapur. Purba Bharati Gas, in which OIL holds 26%, covers two geographical areas in Assam with 15 CNG stations and over 9,000 household connections.
- The grid connection unlocks new customers - once the Duliajan-Numaligarh pipeline is hooked up to the North-East Gas Grid, OIL's gas can reach buyers across the region, and a new 3.5 million standard cubic metre per day feeder line is planned to connect directly to the grid, with completion expected by FY28.
5. New energy: the option on tomorrow
OIL is deploying over ₹20,000 crore by 2040 to build a portfolio of renewables, green hydrogen, biofuels and critical minerals - a hedge funded by today's hydrocarbon cash flows.
- Renewables are being built in partnership - the company has 188 MW of solar and wind capacity installed across Rajasthan, Gujarat and Madhya Pradesh, and a pipeline of roughly 2 GW through joint ventures with state power utilities in Assam, Himachal Pradesh and Rajasthan. A newly formed subsidiary, OIL Green Energy, will house the growing portfolio.
- It is digging for the minerals the energy transition needs - OIL is the first oil-and-gas PSU to enter critical-mineral exploration, having secured a vanadium-graphite block in Arunachal Pradesh and been declared the preferred bidder for a potash-halite block in Rajasthan - the first-ever successful auction of potash blocks by the Government of India.
- Green hydrogen is at pilot stage - a 100-kilowatt green hydrogen pilot plant is operating, a 1-megawatt plant is under construction in Himachal Pradesh, and through NRL a 2,400-tonne-per-year green hydrogen plant is being built.
Group structure and partners
OIL is a government-controlled holding company with a 56.66% state stake, a material refining subsidiary that is now a Navratna in its own right, and a web of international and domestic joint ventures that extend its reach without bloating its balance sheet.
- The Government of India is the dominant shareholder at 56.66%, with the three state-owned fuel retailers - IOCL, BPCL and HPCL - collectively holding just under 10%, and LIC holding 6.86%. OIL itself is a Maharatna, the highest category of central public-sector enterprise, giving it substantial operational autonomy.
- Numaligarh Refinery is the crown jewel - OIL's 69.63% stake in NRL, which was upgraded to Navratna status in December 2025, is the pivot that turned OIL from a pure upstream company into an integrated energy player.
- New energy has its own dedicated vehicle - OIL Green Energy Limited was incorporated in January 2025 as a wholly owned subsidiary to consolidate renewables, green hydrogen, biofuels and carbon-capture projects. A separate 49:51 joint venture with Assam Power Generation Corporation, APGCL OIL Green Power Limited, was formed in February 2025 to execute 645 MW of solar projects in Assam.
- Key partnerships bring technology OIL does not have in-house - TotalEnergies is helping design offshore seismic programmes and detect methane emissions with drone-mounted sensors; Petrobras of Brazil signed an MoU to collaborate on deep-water exploration in the Mahanadi and Andaman basins; and Canada's Petroleum Technology Research Centre is working with OIL on carbon storage and geothermal extraction.