GAS HYDRATE SATURATION ESTIMATED FROM ACOUSTIC IMPEDANCE IN THE ANDAMAN SEA, INDIA

Logging data from the site 17 of the National Gas Hydrate Program 01 (NGHP-01) expedition showed the occurrence of gas hydrate in the volcanic ash sediments of the Andaman Sea, of which the gas hydrate saturation reaches as high as 20% of the pore space, and the gas hydrate saturation in the top 20 m of the BSR is about 10% of the pore space. Acoustic impedance was calculated from the seismic profile using constrained sparse inversion. The water-filled porosity profile was calculated from the cross plot of acoustic impedance and density porosity at the site 17. Gas hydrate saturation was about 6-15% of the pore space calculated from acoustic impedance using Archie equation in the Andaman Sea. The distribution of gas hydrate is heterogeneous in space and the maximum value of saturation is up to 20% of the pore space.