Shale Gas Resources in India

What is shale gas?

• Shale gas forms and stays mainly inside shale.
• Shale is both the source rock and the reservoir.
• In many conventional fields, gas leaves its source rock and collects in a more open reservoir, such as sandstone.
• Coal-bed methane comes from coal, not shale.
• Tight sandstone gas is another separate resource.
• Source: US EIA on gas geology.

Where is the Indian potential?

• The 2016 exam named Cambay, Krishna-Godavari and Cauvery.
• Cambay is in Gujarat.
• Krishna-Godavari spans parts of Andhra Pradesh and Telangana.
• Cauvery covers parts of Tamil Nadu and Puducherry.
• The Directorate General of Hydrocarbons (DGH) also records exploration in Assam and elsewhere.
• Potential is uneven within each basin. Organic content, depth, heat history and cracks all matter.
• Sources: PPAC March 2024 data and US Geological Survey 2011 assessment.

Drill, turn, fracture, produce

1. Explore. Surveys and test wells show if the shale holds gas. They map faults and water layers.
2. Drill and line the well. Steel casing and cement separate it from shallow water.
3. Turn sideways. A horizontal section follows the gas-rich layer.
4. Fracture. Water, sand and additives enter under pressure. Sand keeps the cracks open.
5. Collect. Gas flows up. Some fluid returns with salty water. Both need safe handling.

• Fracking does not break the whole rock layer. Well design and local geology decide the pattern.
• Sources: US EIA on well methods and DGH environmental guidelines.

What the estimates mean

• In 2013, ONGC estimated 187.5 tcf of shale gas resources across five Indian basins.
• A US Geological Survey study estimated a mean 6.1 tcf as technically recoverable.
• The USGS used a narrower area and a different method.
• “In place” gas is gas in rock. “Technically recoverable” is gas that technology may extract.
• Neither proves profitable production.
• Do not turn an old estimate into a current reserve figure.
• Sources: Petroleum Ministry 2015 summary and USGS assessment.

India’s policy and exploration steps

• A 2013 policy let ONGC and Oil India explore shale in their nomination areas.
• The 2016 Hydrocarbon Exploration and Licensing Policy (HELP) brought a single licence for conventional and unconventional hydrocarbons in new acreage.
• A 2018 framework widened access in existing contracts.
• Exploration tests geology and flow. It does not prove a commercial shale industry.
• Petroleum licensing is chiefly a Union matter. States still handle land, local water and pollution consent.
• Sources: Petroleum Ministry policy history and Ministry of Petroleum and Natural Gas on HELP.

A project beside a farming village

• Imagine a company testing shale under farmland. This is a teaching example, not a named project.

1. It studies the rock, tells the regulator where it will drill and secures land and approvals.
2. It records nearby water quality before drilling.
3. The plan names its water source, chemicals, tanks, truck routes and waste route.
4. A test well measures whether gas flows at a useful rate.
5. It checks casing and cement, captures gas and watches for methane leaks.
6. After fracturing, returned water is stored, tested, reused, treated or disposed of under rules.
7. If output is too low, the project may stop. The operator must still secure the well and restore the site.

What must be controlled?

• The USGS finds wastewater disposal is more often linked to felt earthquakes than fracturing itself.
• Sources: USGS on earthquakes, US EPA water-cycle review and DGH guidance.

Energy security and climate limits

• Domestic gas might reduce some imports if wells produce at a useful cost.
• It could supply industry and power plants.
• These are possible benefits, not guaranteed results.
• Burning gas releases CO2. Gas is still a fossil fuel.
• Methane leaks before burning add strong near-term warming.
• A fair comparison counts drilling, leaks, fuel use, water, local harm and the alternative energy.
• Source: IEA methane tracker.

Why the US shale story is not an India forecast

• US output grew with suitable rock, many wells, service firms, pipelines and water access.
• Indian basins differ in depth, thickness, faults, settlements and water stress.
• A US well result cannot be copied to India.
• One test well cannot prove every block of a basin.
• Do not confuse shale gas with offshore conventional gas.

Exam traps

• All three basins have potential. Potential is not production.
• Shale is often both source rock and reservoir.
• Horizontal drilling and fracturing are different steps.
• The 187.5 and 6.1 tcf figures use different scopes. Do not compare them as identical reserves.
• Water, wastewater, methane and local geology decide much of the impact.