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Oil Reserves in Salt Caverns

  May 14, 2023

Oil Reserves in Salt Caverns

Q What is the context  ?

A Central Idea

  • Engineers India (EIL) is conducting a feasibility study for developing salt cavern-based strategic oil reserves in Rajasthan, India, to increase the country’s storage capacity.
  • If successful, it would be India’s first oil storage facility using salt caverns, different from the existing rock cavern-based strategic storage facilities.

salt cavern oil reserve india

Q What are Cavern-based Oil Storage ?


  • Cavern-based strategic oil storage facilities are storage facilities for crude oil or petroleum products that utilize naturally occurring underground caverns for storage purposes.
  • These caverns are typically formed in salt formations or other geological formations through processes such as solution mining or excavation.
  • In the case of salt cavern-based storage facilities, the storage space is created by dissolving salt deposits with water.
  • The process involves pumping water into the geological formations with large salt deposits, which dissolves the salt and creates caverns.
  • Once the brine (water with dissolved salt) is pumped out, the space can be used to store crude oil or other petroleum products.


Q What are the Advantages offered ?

  • Secure and safe: They are naturally well-sealed, providing a secure and impermeable barrier against liquid and gaseous hydrocarbons.
  • Impermeable: This inherent sealing property makes them suitable for long-term storage of oil, minimizing the risk of leaks or environmental contamination.
  • Efficient pumping: Furthermore, cavern-based storage facilities often have high injection and extraction rates, allowing for rapid and efficient operations.
  • Huge capacity: The large volume capacity of caverns enables significant storage capacity, making them ideal for strategic oil reserves intended to address supply disruptions or emergencies.
  • Strategic asset: Countries build strategic crude oil reserves to mitigate supply disruptions and ensure energy security during global supply shocks and emergencies.


Q What is present status of India’s Current Strategic Oil Reserves ?


  • Existing strategic oil storage facilities: India’s three current strategic oil storage facilities are located in Mangaluru, Padur, and Visakhapatnam, consisting of excavated rock caverns.
  • Current capacity and days of demand met: India’s current strategic oil reserves have a capacity of 5.33 million tonnes, equivalent to around 39 million barrels, meeting approximately 9.5 days of demand.
  • Expansion plans: India is in the process of expanding its strategic oil reserves by 6.5 million tonnes at Chandikhol in Odisha and Padur.


Q What is difference between Salt Cavern-Based Reserves vs. Rock Cavern-Based Reserves ?

  Salt Cavern Rock Cavern
Development Process
  • Developed through solution mining
  • Dissolving salt deposits with water to create storage space
  • Excavated from solid rock formations
  • Naturally well-sealed
  • Rapid injection and extraction of oil
  • Less labour-intensive and cost-intensive compared to rock caverns
  • Excavation process
  • Suitable for certain geological formations
Suitability for Oil Storage
  • Low oil absorbency
  • Impermeable barrier
  • Suitable for storing crude oil
  • Depends on specific geological formations
  • May have varying degrees of oil absorbency and permeability

Q What are the examples of Salt Cavern-Based Storage ?

  • US Strategic Petroleum Reserve: The US has the world’s largest emergency oil storage, with storage caverns created in salt domes along the Gulf of Mexico coast. It has a capacity of around 727 million barrels.
  • Salt caverns for other purposes: Salt caverns are also used for storing liquid fuels, natural gas, compressed air, and hydrogen in various parts of the world.

Q What is Potential for such storage in Rajasthan ?

  • Rajasthan’s conducive conditions: Rajasthan, with abundant salt formations, is seen as a favorable location for developing salt cavern-based strategic storage facilities.
  • Previous plans and current renewal: Earlier plans for a strategic oil reserve in Bikaner did not materialize, but the exploration of salt cavern-based storage in Rajasthan can be seen as a renewed proposal.
  • Infrastructure suitability: The presence of a refinery in Barmer and existing crude pipelines in Rajasthan make the infrastructure conducive for building strategic oil reserves.
  • Importance of technology access: Previously, no Indian company possessed the necessary technical expertise for building salt cavern-based strategic hydrocarbon storage.

Q What are the Future plans in India ?

  • Emergency stockpiles: India’s strategic oil reserves are intended to provide emergency stockpiles and are managed by the Indian Strategic Petroleum Reserve (ISPRL).
  • Import protection: The International Energy Agency (IEA) suggests that countries should hold oil stockpiles sufficient for 90 days of import protection.
  • Commercialization plans and partnerships: India plans to commercialize its strategic petroleum reserves through public-private partnerships, reducing government spending and leveraging the commercial potential of the reserves.
  • Recent actions and releases: India took advantage of low crude oil prices to fill its reserves, leading to cost savings. It also released oil from its strategic reserves as part of coordinated actions with other major oil-consuming countries.

Q What can be the Conclusion ?

  • Compared to rock cavern-based reserves, salt caverns offer unique benefits that align with India’s goals of increasing storage capacity and ensuring energy security.