Abstract

Clay-rich marine sediment of Krishna-Godavari (KG) basin in the eastern Indian margin has been described by the Indian National Gas-hydrate Program Expedition-1 as one of the richest hosts of gas-hydrate deposits in the world. Stable carbon isotope analyses indicate most of the gas-hydrate occurrences discovered during this expedition appear to contain predominantly methane which was generated by microbial processes. Resistivity at-bit images and pressure cores reveal that gas-hydrate occurs as either pore-filling grains or particles disseminated in coarser grain sediments or as a fracture-filling material in clay dominated sediments. Sites NGHP-01-3, 14, 15, 16, 17, 19, 20 of KG Basin are the places where gas-hydrate is found in sand layers/laminae within clay-rich sedimentary column.