ONGC starts drilling first deepwater well in Mahanadi basin under Samudra Manthan mission
The Oil and Natural Gas Corporation (ONGC) commenced drilling its first deepwater exploratory well, designated MN-DW18-1-H-D, in the Mahanadi Offshore Basin off the Odisha coast
The well is being drilled roughly 23 nautical miles from Konark under the Union government's Samudra Manthan mission for deepwater and ultra-deepwater hydrocarbon exploration
It is the first of four planned deepwater exploration wells in the Mahanadi Offshore Basin, following earlier Utkal and Konark hydrocarbon discoveries that strengthened the basin's prospectivity
The Ministry of Petroleum and Natural Gas described the spudding as a milestone in India's push to explore energy resources at water depths of up to 3,000 metres in its eastern and western offshore basins
Samudra Manthan Mission and India's deepwater exploration push
The Samudra Manthan mission is the Union government's dedicated programme, coordinated through the Ministry of Petroleum and Natural Gas, the Directorate General of Hydrocarbons (DGH), ONGC and Oil India Limited, to explore and develop India's deep and ultra-deepwater offshore hydrocarbon resources.
Key Details
- ONGC has indicated it may commit up to $20 billion over a five-year offshore exploration programme under the mission, including chartering deepwater drillships and semi-submersible rigs
- The mission targets India's eastern (Mahanadi, Krishna-Godavari, Cauvery) and western (Kerala-Konkan, Andaman) offshore basins, estimated to hold over 5,600 million metric tonnes of oil equivalent (MMTOE) of hydrocarbon potential at depths up to 3,000 metres
- The programme envisages potential collaboration with global majors (such as BP, ExxonMobil, TotalEnergies) for technology and risk-sharing in ultra-deepwater blocks, including in the Andaman offshore area
- It builds on India's Hydrocarbon Exploration and Licensing Policy (HELP, 2016) and the Open Acreage Licensing Policy (OALP), which replaced the earlier New Exploration Licensing Policy (NELP, 1999) to allow operators to carve out exploration blocks and offer revenue-sharing instead of production-sharing contracts
The MN-DW18-1-H-D well is the first concrete drilling operation under Samudra Manthan, translating the mission's stated deepwater ambitions and investment commitments into an active exploration well.
Mahanadi Offshore Basin — geology and hydrocarbon prospectivity
The Mahanadi Offshore Basin lies along India's eastern continental margin off the Odisha coast, formed as a passive-margin sedimentary basin during the break-up of Gondwanaland and subsequent seafloor spreading in the Bay of Bengal. It is classified by the DGH as a Category II (established, moderately explored) basin with proven but underexplored hydrocarbon potential.
Key Details
- Recent discoveries in the basin, including the Utkal and Konark finds, indicated the presence of a working petroleum system in progressively deeper water, prompting the shift to deepwater exploratory drilling
- India's sedimentary basins are officially categorised (I: prolific/producing, II: known accumulations, III: unappraised prospects, IV: frontier/undrilled) as a basis for exploration prioritisation under successive licensing rounds
- The Mahanadi basin sits alongside the Krishna-Godavari basin (India's largest deepwater gas-producing basin) on the eastern offshore margin, sharing a similar passive-margin depositional setting
- Deepwater operations (water depth beyond ~400-1,000 m, depending on classification) require specialised drillships rather than jack-up rigs, reflecting the higher capital intensity of basins like Mahanadi compared with shallow-water fields such as Mumbai High
Classifying Mahanadi's geological setting explains why deepwater-specific rigs and a dedicated mission (rather than routine onshore/shallow-water drilling) were required to test this particular play.
India's energy security and import dependence
India imports a large majority of its crude oil and a significant share of its natural gas requirements, making domestic deepwater exploration a stated pillar of the government's energy self-reliance (Atmanirbhar Bharat in energy) objective.
Key Details
- India's crude oil import dependence stood at approximately 88.5% in FY 2025-26, with natural gas (LNG) import dependence at around 50% of total gas availability, making new domestic discoveries strategically significant for the current account and energy security
- ONGC remains India's largest crude oil and natural gas producer and the principal implementing agency for offshore exploration under government-held acreage
- The government's broader hydrocarbon strategy includes raising the share of natural gas in India's primary energy mix from about 6-7% currently to a stated target of 15% by 2030, alongside expansion of the National Gas Grid and city gas distribution networks
- Deepwater and ultra-deepwater exploration is considered high-risk, high-cost relative to onshore or shallow-water drilling, which is why dedicated missions with ring-fenced investment (such as Samudra Manthan) are used to de-risk and accelerate such campaigns
The Mahanadi deepwater campaign is presented by the government as a direct contribution to reducing India's oil and gas import dependence, situating a single well within the larger energy-security policy narrative.
- Well name: MN-DW18-1-H-D, spudded in the Mahanadi Offshore Basin, approximately 23 nautical miles from Konark, Odisha
- First of four planned deepwater exploration wells in the Mahanadi Offshore Basin under the Samudra Manthan mission
- Samudra Manthan mission envisages up to $20 billion in offshore exploration investment by ONGC over a five-year period
- India's eastern and western offshore basins (up to 3,000 m water depth) are estimated to hold over 5,600 MMTOE of hydrocarbon potential
- India's crude oil import dependence: approximately 88.5% (FY 2025-26); natural gas (LNG) import dependence: approximately 50% of total gas availability
- Licensing framework: Hydrocarbon Exploration and Licensing Policy (HELP, 2016) and Open Acreage Licensing Policy (OALP), which succeeded the New Exploration Licensing Policy (NELP, 1999)