Abstract

The Krishna Godavari (KG) basin is rich in gas hydrate and exhibits an area of wide range of gas hydrate stability zone (GHSZ). In this region, we modeled the base of the gas hydrate stability zone (BGHSZ) utilizing in situ temperature measurements acquired during national gas hydrate program (NGHP) Expedition-01. The bottom simulation reflector (BSR) closely approximates the BGHSZ, and due to the strong temperature influence on hydrate stability, the BSR is close to an isotherm. Thus BSR depth variations can be an indicator for local variations in heat flow, which in turn can be the result of fluid flow or faulting. We are trying to understand the linkage between fluid-flow and vertical fault system in the KG basin. Fluid flow showed a relation to fault systems where some of them are directly connected to gas hydrate bearing sedimentary formations. The influence of water bottom temperature, pore water salinity and geothermal gradient variation on GHSZ thickness is critically analyzed in relation to both geological formations and tectonics. Our analysis suggests a highly variable GHSZ in the KG basin controlled by local variations in the parameters of stability conditions. Recovery of gashydrate sample from the region and presence of gas hydrate above estimated BSR depths may indicate gas-hydrate in thermal equilibrium.