Brief Summary, Prospect in India, Opportunities & Challenges

ABOUT SHALE GAS

Shale Gas is natural gas produced from shale formation that typically function as both the reservoir and source rocks for the natural gas. In terms of its chemical makeup, shale gas is typically a dry gas composed primarily of methane (at least 90 % methane).

Shale is a sedimentary rock i.e. formed by deposition of mud in consolidated form. During deposition of these very fine grained sediments, there can be accumulation of organic matter in the form of algae plant, animal derived from organic debris. These organic materials become a source of hydrocarbon which is known as Shale Gas.

EXTRACTION FOR COMMERCIAL USE

Shale Gas is abundant in the earth’s surface and recent technology developments have made it possible to extract commercially. The present technology involves use of horizontal drilling and hydraulic fracturing of shale known as Fracking.

AVAILABILITY IN INDIA

As per the estimate, India is believed to have 300 TCF (trillion cubic feet) of shale gas. This is enormously larger than KG6 Gas which is only 7-8 TCF. The identified regions are – Cambay, Assam- Arakan, Gangetic Basin, Gondwana, KG onshore and Cauvery onshore.

EMISSIONS

Shale Gas only emits 50% of Carbon dioxide as compared to coal hence, it can be termed as ecological friendly. However, if leakages are not prevented during extraction then, there will not be any benefit on carbon footprint.

WHY INDIA NEEDS

The importance of shale gas in India is due to the fact that India has limited source of conventional gas reserve. The present production of gas is 140 mscmd (million standard cubic metres per day) which can go upto 220 mscmd during 12^th Plan (2018). However, the gas demand is expected to be 290 mscmd in 2013 and 470 mscmd in 2018, hence, production of shale gas requires as serious thought. The beginning has been made by digging a well for shale gas at Durgapur few months back. Regulatory laws and guidelines need to be framed.

LIMITATIONS 

i)Requirement of vast tract of land

ii)Possible damage to the environment such as land contamination and sub soil water contamination

iii)Commercial success yet to be proved in India

Attached: Some photographs of shale gas extraction

       SHALE GAS DRILLING ILLUSTRATION

GEOLOGY OF SHALE GAS

HORIZONTAL DRILLING

HYDRAULIC FRACKING