Strategic Petroleum Reserve

Also called: SPR · Topic: Energy Resources of India: Conventional and Non-conventional · NCERT: Beyond NCERT

Meaning

A Strategic Petroleum Reserve (SPR) is a stock of crude oil that the government stores for emergencies, such as a war or a break in world oil supply. India keeps its reserve in underground rock caverns (large tunnels dug into hard rock) on the coast [1].

• Why it matters: India buys about 88% of its crude oil from abroad [3]. If supply suddenly stops, the SPR can keep refineries working for a while.
• It is one of India's main tools for energy security (making sure the country always has enough energy at a fair price).

Explanation

How it works: cause → process → result

• Cause: India depends on imports.
• Most of India's oil lies in a few sedimentary basins at the edges of the country. Home production is far below demand.

• Imported crude must pass through narrow sea routes and choke points (narrow sea passages that are easy to block), such as the Strait of Hormuz [3].

• Process: oil is stored in good times.

• Tankers bring imported crude to the coast.

• The crude is pumped into underground caverns and kept there.

• Result: oil is released in bad times.

• In a crisis, the stored crude is sent quickly to nearby coastal refineries.
• This gives the country time to find other suppliers.

Why underground rock caverns

• Hard rock surrounds the cavern on every side, so the oil stays safely inside.
• They are safer than tanks on the surface. They are also hard to attack or damage.
• They are cheaper than building many large steel tanks above ground [1].
• They take up little land on the surface.

The two phases

• Who builds and runs it: ISPRL (Indian Strategic Petroleum Reserves Ltd), a company the Government of India set up for this work [1].
• Phase I (complete): 5.33 MMT (million metric tonnes) at three sites [1].
• Visakhapatnam (Andhra Pradesh): 1.33 MMT
• Mangaluru (Karnataka): 1.5 MMT

• Padur (Udupi, Karnataka): 2.5 MMT

• Phase II: 6.5 MMT at two sites [2].

• Chandikhol (Jajpur, Odisha): 4 MMT
• Padur (Karnataka): 2.5 MMT
• The Union Cabinet approved it on 8 July 2021 [2].
• It is to be built by Public–Private Partnership (PPP), where the government and private companies share the work and cost [2].
• It will have its own single point moorings (buoys out at sea where tankers tie up and unload) and pipelines [2].

Conditions a site needs

• A coastal location. Tankers can unload imported crude straight into the caverns.
• Refineries nearby. The stored oil can reach them fast in an emergency.
• Hard, solid rock. Large caverns can be dug into it and stay stable.

Where it occurs

• Who and what: a Government of India programme, run by ISPRL [1]. Phase II was approved in 2021 [2].
• East coast:
• Visakhapatnam (Andhra Pradesh, Bay of Bengal coast): Phase I, 1.33 MMT [1].

• Chandikhol (Jajpur district, Odisha): Phase II, 4 MMT, the largest single site [2].

• West coast (Karnataka, Arabian Sea coast):

• Mangaluru: Phase I, 1.5 MMT [1].

• Padur (Udupi district): 2.5 MMT in Phase I and another 2.5 MMT in Phase II [1][2].

• Link to refineries: Visakhapatnam and Mangaluru are also coastal refinery centres that mainly process imported crude.

Site	State	Phase	Capacity
Visakhapatnam	Andhra Pradesh	I	1.33 MMT [1]
Mangaluru	Karnataka	I	1.5 MMT [1]
Padur	Karnataka	I	2.5 MMT [1]
Chandikhol	Odisha	II	4 MMT [2]
Padur	Karnataka	II	2.5 MMT [2]

Don't confuse with

• Oilfield (such as Digboi, Ankleshwar, Mumbai High): oil forms and is found there naturally. An SPR site only stores imported crude. Padur and Chandikhol are not oilfields.
• Anticline trap: a natural upfold in rock layers where oil collects under a non-porous cap rock. SPR caverns are man-made tunnels dug into hard rock.
• Refinery (such as the Mangaluru or Visakhapatnam refinery): it processes crude into petrol, diesel and other products. The SPR only holds crude. It refines nothing.
• Phase I vs Phase II: Phase I (5.33 MMT, three sites) is complete and was built by ISPRL [1]. Phase II (6.5 MMT, Chandikhol and Padur) is planned under PPP [2].

Prelims Hooks

• Phase I SPR sites (5.33 MMT): Visakhapatnam (Andhra Pradesh), Mangaluru and Padur (both Karnataka) [1].
• Phase II SPR sites (6.5 MMT): Chandikhol (Odisha, 4 MMT) and Padur (Karnataka, 2.5 MMT) [2].
• Padur is the only site in both phases. Trap: Chandikhol is in Odisha (Jajpur), not Andhra Pradesh [2].
• Largest single site: Chandikhol (4 MMT). Smallest: Visakhapatnam (1.33 MMT) [1][2].
• Storage type: underground rock caverns, not surface tanks. The builder is ISPRL [1].
• Phase II was approved on 8 July 2021, uses the PPP model and has its own single point moorings [2].

Mains Points

• Energy security (GS-III): India imports about 88% of its crude [3]. This exposes it to price shocks and to blockades at choke points such as the Strait of Hormuz.
• The SPR gives a buffer in a crisis [1][2].

• It works with other steps: buying from about 40 countries, and sending about 70% of crude imports by routes outside Hormuz [3].

• Location logic: all SPR sites are on the coast, on both the east and west coasts.

• Tankers can unload straight into the caverns, so no long inland pipelines are needed.
• Coastal refineries nearby can get the oil quickly.

• Having sites on two coasts means one regional disruption cannot cut off every reserve.

• Policy shift to PPP: Phase II brings in private partners [2].

• This lowers the burden on the government's budget.
• It still adds national storage, alongside more exploration under OALP [4] and a move towards non-fossil energy.

Related concepts

• Petroleum
• Anticline trap
• Oil and Natural Gas Commission
• Digboi oilfield
• Naharkatiya oilfield
• Cambay basin
• Mumbai High
• Barmer oil fields
• Krishna-Godavari basin
• Field-based and market-based refineries

Read more

• Petroleum: occurrence, oilfields, refineries and reserves