Characteristic of gas hydrates reservoir from seismic analysis of multichannel seismic profiles offshore South Chile

We used a procedure already tested in order to characterize the gas hydrate and free gas reservoir along South Chile. We used the multichannel seismic data to obtain an accurate velocity model by using the Pre stack Depth Migration. The velocity model can be then extrapolated in terms of gas-phase concentrations. We recognized a high (2200 m/s) and low (1268 m/s) velocity layer associated to gas hydrate and free gas presence, respectively. The highest gas hydrates and free gas concentrations were detected offshore Coyhaique (at 44.5°S) with an average of 12% and 1% of total volume, respectively. By using the instantaneous amplitude, in particular using the BSR/seafloor ratio we conclude that the RC2901-728 section located northernmost (close to 36°S), also can be considered an interesting reservoir of gas hydrates and free gas because of the high estimated values of the BSR/seafloor ratio (>0.5).