Gas Hydrate: India’s tapping prospects

Context: The National Gas Hydrate Programme (NGHP) was initiated in 1997 to explore and develop gas hydrate reserves. Despite three decades of effort, commercial extraction remains unachieved.

Methane Hydrate

• Methane Hydrate is a crystalline solid that consists of a methane molecule surrounded by a cage of interlocking water molecules.
• Alternate names: Methane Hydrate is also known as: Methane clathrate, hydromethane, methane ice, fire ice, natural gas hydrate, and gas hydrate.
• Category: Classified as ‘unconventional hydrocarbons,’ similar to coal bed methane. Most methane hydrate deposits also contain small amounts of other hydrocarbon hydrates (propane hydrate and ethane hydrate).
• Occurrence: 
  • Formed under conditions of high-pressure and low-temperature, typically found in deep-sea sediments and permafrost regions. 
  • India’s reserves are primarily in the Krishna-Godavari (KG) basin, Mahanadi basin, and near the Andaman Islands.
• Difficult to Handle: If the ice is removed from this temperature/pressure environment, it becomes unstable. For this reason, methane hydrate deposits are difficult to study and handle.
  • They cannot be drilled and cored for study like other sub-surface materials, because as they are brought to the surface, the pressure is reduced and the temperature rises.
  • This causes the ice to melt and the methane to escape.

India’s Gas Hydrate Potential

• India’s estimated gas hydrate reserves: 1,894 trillion cubic metres (tcm) (as per IEA’s India Energy Outlook 2021).
  • 1 cubic metre of gas hydrate contains 160-180 cubic metres of methane.
  • Even the lowest estimate of KG Basin methane hydrates is twice the world’s total fossil fuel reserves.

Challenges in Gas Hydrate extraction

1. Technical challenges:

• Sea-floor subsidence:
  • Gas extraction can cause sinking of the seabed.
  • Solution: Measured extraction techniques can stabilise the seabed over time.
• Gas leaks and environmental concerns:
  • Uncontrolled methane release can harm marine ecosystems and contribute to global warming.
  • Solution: Controlled depressurisation and advanced monitoring systems.
• Water release and treatment:
  • Extracting gas from hydrates releases significant amounts of water, which must be treated before being returned to the sea.
  • Solution: The use of Floating Production, Storage, and Offloading (FPSO) systems, common in offshore oil production.

2. Economic and Policy constraints:

• High cost of extraction:
  • Gas from hydrates is more expensive than imported natural gas.
  • Without a market premium or government incentives, private oil companies have little motivation to explore hydrates.
• Government's Hands-off approach:
  • Under India’s new petroleum licensing policy, the responsibility of gas hydrate extraction is left to private concessionaires.
  • This has led to reduced direct government involvement in research and exploration.

Slow Progress under National Gas Hydrate Programme (NGHP)

• Drilling expeditions: Two major expeditions conducted by the Directorate General of Hydrocarbons (DGH):
• 2006: Identified a 120-metre-thick hydrate zone in the KG basin, 40 metres below the seabed.
• 2015: Confirmed the deposits and mapped a 150 sq. km prospective zone in the KG basin.
• Since 2015, there has been no significant progress.
• Lack of commercial extraction:
  • Countries like the US, Canada, and Japan have also struggled with gas hydrate extraction but have made more progress.
  • The US has prioritised shale gas over hydrates due to economic viability.
  • Japan has carried out trials in the Nankai Trough, but it has not yet reached commercial extraction.

Need for Long-Term Vision

• National Importance: Oil Industry Development Board (OIDB) in 2016 stressed the strategic significance of gas hydrates.
• Energy Security: A 2020 Ministry of Science and Technology release emphasized India’s vast untapped potential.
• Expert Recommendations: Scientists suggest that domestic gas hydrate extraction could reduce long-term costs despite initial high investments.

Way Forward

• Government Intervention:
  • The government must take a proactive role, offering incentives for exploration and research.
  • Subsidies or pricing mechanisms should be introduced to encourage investment in gas hydrate extraction.
• Technology Development and Collaboration:
  • Collaboration with global leaders like Japan and the US can help India develop viable extraction technologies.
  • Investment in seabed methane capture and controlled extraction technologies is needed.
• Environmental and Regulatory Framework:
  • A robust framework to manage ecological risks, methane leaks, and water disposal is essential.
  • Strict-monitoring and sustainable extraction practices must be mandated.