Prof. D. N. Singh

JEEVAN JOSEPH

Ph. D.
Indian Institute of Technology Bombay, Powai, India jeev.jsph@gmail.com

EVALUATION OF GAS AND WATER PERMEABILITY IN GAS HYDRATE BEARING SEDIMENTS

Methane gas hydrates are the clathrates containing methane gas entrapped inside the water molecules. Incidentally, the gas production from the sediments bearing these clathrates, by thermal stimulation and/or depressurization, is primarily dependent on their gas and water permeability. However, the challenges associated with (i) the synthesis of hydrates in the laboratory and (ii) maintaining thermodynamic conditions to counter hydrate dissociation, while performing permeability tests, are major challenges to all those venturing into this nascent field of ??energy geotechnics?. In this context, development of laboratory setups that are: (i) easy to operate and economical, and (ii) suitable for the porous media with different textures and the desired state of compaction, becomes essential. With this in view, two setups: (i) Gas Conductivity Measuring device,?GasCoM, and (ii)?GasCon-TP, which can be utilized to determine gas permeability through soils under ambient conditions and varied environmental conditions, respectively, have been developed and their utility has been demonstrated. A critical synthesis of the results from these studies reveals that the gas permeability through the porous media gets significantly influenced by (a) the saturation (in terms of water and ice) state, (b) pore-size distribution characteristics and (c) the properties of the gas. Furthermore, based on extensive experimentations, mathematical relationships that can be employed for estimating the gas and water permeability have been developed, and their utility and efficiency has been demonstrated.