Why this is a well-data question, not just a policy question

A ₹20,000 crore CCUS Mission (covered in detail in this blog's separate piece on India's Net Zero scenarios) answers the question of who pays to capture carbon dioxide from power plants, cement kilns, steel mills, refineries and chemical plants. It does not by itself answer a separate, physically unavoidable question: once captured, where does the CO₂ actually go? The honest answer is that nobody is starting from scratch on this — India has been drilling, logging, and seismically surveying its sedimentary basins for oil and gas since before independence, and that decades-deep well and seismic record, held centrally in the National Data Repository (NDR) run by the Directorate General of Hydrocarbons (DGH, under the Ministry of Petroleum and Natural Gas), is the foundational dataset every subsequent CO₂-storage assessment in India draws on, whether the assessment is done by ONGC, Oil India, an IIT, or an academic research group. This piece did not find a DGH-authored report specifically titled or framed as a CCUS storage assessment; DGH's actual role is narrower and still essential — it is the data custodian other bodies build their own storage assessments on top of.

The named basins — and the difference between naming a basin and identifying a well

NITI Aayog's own January 2025 workshop on CCUS in the cement sector named the country's principal storage opportunities directly: "India has immense potential for CCUS, with regions like the Krishna-Godavari Basin, Deccan Traps, and mature oil and gas fields offering substantial CO₂ storage capacity." Separate reporting on the same theme adds the Cambay Basin, the Cauvery Basin, Mumbai Offshore, and the Assam-Arakan Fold Belt to that list — the same handful of hydrocarbon-bearing sedimentary basins that show up in DGH's own shale-gas and coalbed-methane resource assessments, because they are the basins India has decades of well and seismic data for in the first place.

That distinction matters. A basin being named as a storage opportunity in a workshop presentation is a geological screening judgement; it is not the same as identifying a specific depleted reservoir, characterising its caprock integrity, and confirming injectivity through an actual well test. As of this piece's research, only two of the named basins — Cambay and the Assam-Arakan Fold Belt — have a named, well-level pilot project actually under way. The rest remain named opportunities on a map, not yet identified wells.

The two real pilots

ONGC's first full-scale CCS pilot, announced in early January 2026, will inject captured CO₂ into two abandoned onshore wells at its Gandhar field, Gujarat — part of the Cambay Basin, one of India's oldest and most thoroughly drilled hydrocarbon provinces. The plan is to inject roughly 100 tonnes of CO₂ a day, sourced from nearby industrial emitters in the Dahej cluster as well as ONGC's own Hazira plant, into subsurface hydrocarbon reservoirs — with a secondary objective of testing CO₂-enhanced oil recovery (CO₂-EOR) at the same wells, turning the injected gas into a production tool rather than pure disposal. ONGC has said it will engage a specialised CCUS consultant for feasibility work and regulatory guidance, which suggests the well-selection and injectivity case is still being finalised in detail even as the pilot is publicly announced. This builds on a December 2022 memorandum of understanding between ONGC and Shell specifically to conduct joint CO₂ storage and EOR-assessment studies across basins with depleted oil and gas fields and saline aquifers — meaning the Gandhar pilot is the concrete output of a three-year-old study partnership, not a standing start.

Oil India Limited's parallel effort sits in the Assam-Arakan Fold Belt, targeting the Barail and Tipam geological formations. OIL's Chairman and Managing Director, Dr Ranjit Rath, said in February 2024: "We are looking at our depleted fields, abandoned wells and exploring using these fields for storing either carbon or gas. We have shortlisted five. Studies are underway to see how CO₂ behaves when injected into these rock formations." Unlike ONGC's Gandhar announcement, this piece did not find a subsequent, more specific update naming which five fields were shortlisted, what stage the injectivity studies have reached as of 2026, or a target injection volume — the February 2024 statement remains the most specific public account this piece could locate.

The capacity numbers don't agree with each other, and that's worth saying plainly

Published capacity estimates for the same rock vary by roughly two orders of magnitude, depending entirely on what is being measured. A hydrocarbon-reservoir-specific estimate for the Cambay Basin — storage capacity in already-characterised oil and gas fields, calculated from ultimate recoverable reserves plus CO₂-EOR potential — puts the figure at more than 650 million tonnes. Separate academic literature estimating India's saline aquifer storage potential nationally — a much larger, less characterised rock volume that includes but is not limited to Cambay — puts the range at 50 to 270 billion tonnes, and a combined multi-basin onshore estimate cited in industry literature lands at a mid-case of 74.8 billion tonnes. These are not competing answers to the same question; they are answers to three different questions (one basin's proven hydrocarbon reservoirs; the nation's saline aquifers broadly; a multi-basin onshore composite), and this piece deliberately does not average or reconcile them into one headline number, because doing so would imply a precision the underlying data doesn't support.

A separate, non-well storage track: coal seams, not oil fields

Not every Indian CO₂-storage initiative runs through DGH's oil-and-gas well data at all. In November 2022, NTPC's own R&D arm (NETRA), NITI Aayog, and the National Centre of Excellence in Carbon Capture & Utilisation (NCoE-CCU) at IIT Bombay launched a separate assessment of CO₂ storage potential specifically in coalbed methane (CBM)-rich coalfields, including fields NTPC itself holds, aiming to produce a "CO₂ Storage Atlas" for selected Indian coalfields within twelve months of the November 2022 launch. This piece could not find a published version of that Atlas or a status update on its completion, roughly three-and-a-half years after the stated timeline — an absence this piece treats as informative rather than as confirmation the work stalled, consistent with how it has treated similar silences elsewhere. Coal seams are a geologically distinct storage medium from depleted oil and gas reservoirs or saline aquifers (CO₂ adsorbs onto coal rather than filling pore space), and NTPC's initiative sits organisationally and geologically apart from the DGH-well-data-driven ONGC and OIL India work described above.

Sources and caveats