Prediction of the methane supply and formation process of gas hydrate reservoir at ODP 1247, Hydrate Ridge

The formation of gas hydrate reservoir in marine sediments is mainly controlled by methane supply and sedimentary burial. Based on mass balance in marine gas hydrate system, a numerical prediction model of gas hydrate formation was established considering the methane supplied by dissolved methane diffusion and porewater advection and in-situ methanogenes. A case study of ODP sites 1247 shows that dissolved methane transported by molecular diffusion and porewater advection is the major supply of methane for gas hydrate formation, while in-situ methanogenesis contributes little to the gas hydrate reservoir. The gas hydrate reservoir was slightly changed by the variation of sedimentary rate since 1. 67 Ma B.P. The model-derived hydrate saturation is similar to 0 similar to 3% up to date, which is consistent with that determined through ODP drilling