Context:

Government-owned engineering consultancy firm Engineers India (EIL) is studying the prospects and feasibility of developing salt cavern-based strategic oil reserves in Rajasthan, in line with the government’s objective of increasing the country’s strategic oil storage capacity.

About Salt Cavern-Based Reserves:

• Salt Cavern-Based Reserves refers to underground storage facilities created within natural salt formations. 
• These caverns are typically created by dissolving the salt through solution mining, creating large underground chambers.
• They can be used to store various substances, including hydrocarbons, natural gas, petroleum products, and compressed air.

How Salt Cavern-Based Reserves are formed: 

• Salt caverns are developed by the process of solution mining, which involves pumping water into geological formations with large salt deposits to dissolve the salt. 
• After the brine (water with dissolved salt) is pumped out of the formation, the space can be used to store crude oil.

Benefits of Salt-Based  Caverns: 

• Simpler Process than Rock Caverns: The Process to develop Salt-Based  Caverns is simpler, faster, and less cost-intensive than developing excavated rock caverns.
• Better Storage Facility: Salt cavern-based oil storage facilities are also naturally well-sealed, and engineered for rapid injection and extraction of oil. 
• Low Oil Absorbency: The salt that lines the inside of these caverns has extremely low oil absorbency, which creates a natural impermeable barrier against liquid and gaseous hydrocarbons, making the caverns apt for storage. 
• Salt caverns are used to store liquid fuels and natural gas, compressed air and hydrogen.

What are Strategic Petroleum Reserves (SPR)?

• SPR are large stockpiles of crude oil and petroleum products maintained by many countries, primarily for emergency situations or times of severe supply disruptions.
• Nodal Agency: Indian Strategic Petroleum Reserve (ISPRL) under the aegis of Ministry of Petroleum and Natural Gas.

• India’s existing SPR facilities: 
  • Mangaluru and Padur in Karnataka
  • Visakhapatnam in Andhra Pradesh. 

• Present SPR capacity: 5.33 million tonnes, or around 39 million barrels of crude, that can meet around 9.5 days of demand.
• Planned SPR capacity: 6.5 million tonnes at two locations — Chandikhol in Odisha (4 million tonnes) and Padur (2.5 million tonnes).
• Other storage facilities apart from the SPR: The oil marketing companies (OMCs) have storage facilities for crude oil and petroleum products for 64.5 days — which means there is sufficient storage to meet around 74 days of the country’s petroleum demand.

News Source: Indian Express