Oil Reserves in Salt Caverns [UPSC Notes]

A government-owned engineering firm Engineers India (EIL) is exploring the prospects and feasibility of developing Rajasthan’s salt caverns into petroleum reserves. In this article, you can read more about this development, the feasibility of salt caverns as strategic petroleum reserves and the differences between salt cavern-based reserves and rock cavern-based reserves of petroleum. This topic is relevant for the IAS exam from multiple perspectives such as economy, environment as well as geography.

Salt Caverns as Strategic Petroleum Reserves

At present, India has strategic petroleum reserves at 3 places namely, Mangalore and Padur in Karnataka, and Visakhapatnam in Andhra Pradesh constructed from excavated rock caverns.

• The major objective of building strategic petroleum reserves is to ensure safety or protection against supply chain disruptions and ensure energy security and availability during global supply shocks and other emergencies.
• It is particularly important for India to build strategic petroleum reserves as India is the third-largest consumer of crude, depending on imports for more than 85% of its requirement.
• The present strategic petroleum reserve capacity of India is 5.33 million tonnes, or around 39 million barrels of crude which can meet 9.5 days of demand. At the same time, the oil marketing companies (OMCs) have storage facilities for crude oil and petroleum products for 64.5 days which sums up to a total of 74 days of the country’s petroleum demand.
• The International Energy Agency (IEA) recommends holding a stockpile that can sustain for 90 days.

Difference Between Salt Cavern-based Reserves and Rock Cavern-based Reserves

• Salt cavern-based reserves are considered attractive because they are naturally well-sealed, and engineered for rapid injection and extraction of oil.
• 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 for storing liquid fuels, natural gas, compressed air and hydrogen.

Potential Site:

• In the past decade, there was a proposal for developing a strategic petroleum reserve in Bikaner district of Rajasthan but the project still needs to be initiated. 
• The present attempt of examining the possibility of a salt cavern-based strategic reserve is the revival of the proposal.
• Rajasthan is a state that consists of salt caverns and also has crude oil pipelines and an upcoming refinery in Barmer which makes it an ideal site.
• Engineers India Limited is partnering with German-based DEEP.KBB GmbH company since no other Indian company has the technology to develop a salt cavern into a strategic petroleum reserve.
• India has decided to commercialise the strategic petroleum reserves which resulted in Abu Dhabi National Oil Company (ADNOC) storing about 0.8 million tonnes of crude oil in the Mangaluru strategic reserve.

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