Informatics Publishing Limited

Kalachand Sain ¹, Maheswar Ojha ¹, Nittala Satyavani ¹, G. A. Ramadass ², T. Ramprasad ³, S. K. Das ⁴, Harsh Gupta ¹

Affiliations
1 CSIR - National Geophysical Research Institute, Uppal Road, Hyderabad - 500 007, IN
2 National Institute of Ocean Technology, Velachery-Tambaram Main Road, Chennai - 600 100, IN
3 CSIR-National Institute of Oceanography, Dona Paula, Goa - 403 004, IN
4 Ministry of Earth Sciences, Prithvi Bhavan, Lodhi Road, New Delhi - 110 003, IN

Abstract

Gas-hydrates are crystalline substances consisting of mainly methane and water, and occur in shallow sediments of outer continental margins and permafrost regions. They are formed at high pressure and low temperature regime when supply of methane gas exceeds the solubility limit. Unlike natural gas, oil and minerals, gas-hydrates are not stable at standard temperature and pressure (STP). One volume of gas-hydrates, when dissociated, releases 164 volumes of methane at STP. Since methane is the lowest molecular weight hydrocarbon, use of gas-hydrates as fuel will cause less pollution to the environment. These have attracted the global attention due to their natural occurrences in abundance and huge energy potential. The methane locked as gas-hydrates is envisaged as 1-120 x 10¹⁵ m³ (Boswell and Collett, 2011). Only 15% recovery from this gigantic reserve may be sufficient to meet the global energy requirement for about 200 years (Makogon et al. 2007). Thus, gas-hydrates seem to be a viable major energy resource of future, and have been identified globally either by geophysical, geochemical and geological surveys or by drilling and coring (Boswell and Saeki, 2011; Ruppel, 2011; Sain and Gupta, 2012). Besides having the energy potential, the study of gas-hydrates is also important from natural hazards point of view related to seafloor subsidence, slumps and slides (Gupta and Sain, 2011).

Full Text