Natural Gas, First Strategic Natural Gas Reserves in India

First Strategic Natural Gas Reserves

• Context (TH): GAIL is looking at building India’s first strategic natural gas reserves by using old, depleted hydrocarbon wells.
• India has 5 million tonnes of strategic petroleum reserves but no storage facilities for natural gas.

Natural Gas

• Natural gas is a fossil fuel that primarily consists of methane.
• Natural gas reserves are deep inside the earth near other solid and liquid hydrocarbon beds like coal and crude oil.
• It is not used in its pure form; it is processed and converted into cleaner fuel for consumption.
• By-products extracted: Propane, ethane, butane, carbon dioxide, nitrogen etc.
• It also contains nonhydrocarbon gases, such as carbon dioxide and water vapour.

Types of Natural Gas

• Wet gas or Associated gas: Natural gas found in association with crude oil.
• Dry gas or Non-associated gas: When reservoirs contain only gas and no oil.
• Coalbed methane: Natural gas found in coal deposits.
• Sour gas: Natural gases that contain hydrogen sulfide or other organic sulfur compounds.
• Sweet gas: Coalbed methane is called ‘sweet gas’ because it lacks hydrogen sulfide.
• Shale gas or Tight gas: Natural gas that occurs in the pores of shale, sandstone, and other sedimentary rocks.

Benefits of Natural Gas as Fuel

• Clean burning: Natural gas burns cleaner than other fossil fuels, emitting fewer air pollutants and greenhouse gases.
• Efficient: It has a high energy conversion efficiency, minimising waste and maximising utilisation.
• Versatile: It can be used for various purposes like cooking, generating electricity, and powering industrial processes.
• Flexible: Liquified and compressed natural can be easily transported and stored.

Disadvantages of Natural Gas as Fuel

• Contributes to greenhouse gas emissions despite cleaner burning.
• Methane, a potent greenhouse gas, can leak during natural gas extraction, processing, and transportation.
• Natural gas extraction from shale and tight formations often relies on fracking, which can have environmental impacts like water contamination and seismic activity.
• Non-renewable: Natural gas is a finite resource that cannot be replenished.
• Transportation: Its transportation requires specialised infrastructure.

Natural Gas Storage

• Underground storage: Utilising depleted gas fields, salt caverns, and other geological formations.
• Above-ground storage: Utilising specially designed tanks for smaller-scale storage.

Benefits of Underground Storage of Natural Gas

• Large capacity
• Higher energy efficiency: Natural pressure and temperature in underground formations maintain stored gas in a condensed state, minimising energy losses during storage and retrieval.
• Cost-effective
• Safe and secure: It minimises the risk of leaks and ensures the safety of the surrounding environment.
• Long-term storage
• Grid reliability: Underground storage ensures a reliable natural gas supply during peak demand, maintaining grid stability and preventing power outages.