Cryogenic gas hydrates on the Arctic shelves: forecast features and resource assessments

The study is dedicated to the features of forecasting and quantitative assessment of methane resources in subaqueous cryogenic gas hydrates on the Russian Arctic shelf. The work is based on numerical modeling of submarine permafrost and the thermal regime of marine sediments. As a result of the mathematical modeling, equilibrium curves of hydrate formation with variable seawater salinity were constructed. These curves facilitated the determination of the spatial boundaries of cryogenic gas hydrate stability zones. In regions with predicted cryogenic gas hydrate stability zones, potentially hydrate-bearing accumulations were delineated based on Common Depth Point (CDP) seismic data. The amount of methane in four forecasted sub-permafrost gas hydrate accumulations on the Laptev Sea shelf was estimated. The identified accumulations are projected to contain approximately 0.1 trillion cubic meters of methane in hydrate form. According to the regional-scale assessments, up to 9.24 trillion cubic meters of methane, or about 0.3% of the global gas-in-place assessments, may be accumulated on the Russian Arctic shelf.