Gas Hydrate: Possible Source of Energy from Ocean

Gas hydrate is a solid material, formed from water and hydrocarbon (mainly methane) having micro particle weight, which is also known as clathrate. It is extensively distributed in oceanic and polar sediments, where the temperature is very low and the pressure is very high. Under such conditions, methane gas gets crystallized and converts into solid gas hydrate. Large number of storages being available world wide and its being a suitable source of energy, attention of the scientists of the whole world attracted towards gas hydrate. There is enough possibility of accumulated energy in methane deposited under hydrate sediment. There is an assumption that gas hydrates have double energy as compared to total fossil fuel energy storage of the world. But as yet there is no sufficient knowledge regarding all specifications of gas hydrate and its proper distribution. Even today there is no proper technique available for the estimation of quantity of gas hydrates. Different parameters such as bathymetry, Sea bed temperature, sedimentation, total organic carbon content etc. have indicated that there are suitable conditions for the deposition of gas hydrate in coastal areas of eastern and western India. Therefore, it was felt necessary to identify gas hydrate and the determination of its quantity for evaluation of its possible resources, near the boundaries of Indian continent, sufficient geo-scientific, geochemical and geo-physical analysis should be carried out. Leakage of gas from the bottom of the ocean in any region; availability of Bottom Simulating Reflector (BSR) in the region; irregular quantities of chloride and sulfate etc. are the useful indications by means of which presence of gas hydrate in deep ocean can be identified. To identify hydrate and quantity free gas tomography, AVO wave structure etc. are some very important resources. In those areas where there is no indication from seismic method, gas hydrates can be identified by irregularity of electrical resistance. Here, we have described some important explorational studies and techniques conducted in deep water, by which along with identification of the gas hydrate oriented areas gas hydrate and the quantity of free methane gas present in the lower layer can be estimated. Department of Ocean Development has commenced duly planned scientific exploration work in this important area.