Question – What is Shale Gas? Discuss the method and challenges of its extraction by mentioning its reserves in India. – 11 December 2021
Answer – Shale gas is a type of natural gas, which is produced from the organic elements available in shale. The production of shale gas requires Artificial Stimulation such as hydraulic fracturing.
India is one of the world’s largest energy consumers, but it itself is not endowed with sufficient energy resources. Excessive dependence on imported energy threatens the financial stability and energy security of the country. Therefore, radical changes in shale gas extraction may lead to some improvement.
The study conducted by the United States Geological Survey has estimated the available resources in 3 out of 26 sedimentary basins of India. Six potential shale gas basins in India have been identified by the Ministry of Petroleum. These are the following:
- Assam-Arakan Basin
- Gondwana Basin (Damodar Valley)
- Krishna-Godavari Basin
- Cauvery Basin
- Cambay (Khambhat) Basin
- Indo-Gangetic Basin
Technical Challenges for Shale Gas Extraction:
- Shale rocks are accessed by horizontal drilling to extract shale gas or they are broken by hydraulic fracturing because some shale rocks have fewer holes and are easier to inject fluid. can’t come out
- Therefore, in such a situation, their reservoir is not like a well but is spread all around. Horizontal drilling is used to extract gas from these rocks.
- Millions of tons of water, small pieces of rock (propant) and chemicals are pumped through holes inside the respective rocks for hydraulic dissolution.
- It is noteworthy that in recent years the techniques of horizontal drilling and hydraulic fracturing have made it possible to access large reserves of shale gas.
- However, accepting this challenge, the Directorate General of Hydrocarbons (DGH) has issued guidelines on environmental management during shale gas extraction.
- It states that the total volume of fracture fluid is 5 to 10 times that of conventional hydraulic fracturing and fracturing activities, which can cause contamination due to depletion of water sources and settling of flowback water.
- However, the process of environmental impact assessment does not differentiate between conventional and non-conventional hydrocarbons and DGH recognizes that the EIA process does not differentiate between conventional and unconventional gas exploration in the region.
In addition to the above mentioned technical challenges, shale gas extraction will also require addressing the following issues:
- Regulatory and Environmental Framework: The production of shale-gas results in large scale water contamination.
- Availability of open land: In comparison to natural gas, shale gas production requires a large area of land for exploration and extraction.
- Availability of water: The massive use of water in the process of extraction is a challenge for India facing water crisis.
- Rationalization of gas prices: This is essential for boosting investment and investor confidence.
Due to stagnation in oil and gas production and increasing dependence on imports, it would be a right move to try to address the above challenges to tap the potential of shale gas. The Hydrocarbon Exploration and Licensing Policy (HELP) 2016 recently adopted by the Government of India for grant of Integrated Licensing and other attractive measures paves the way for the future.