Mathematical Model of Degradation of Frozen Hydrate-Bearing Saline Rocks Under Thermal Influence from Above and Below

A mathematical model has been formulated to describe the degradation of saline permafrost containing ice, gas hydrate accumulations, and free gas, as a result of climate warming and the influence of heat flow from below, considering the effects of osmosis. The degradation rates of hydrate-bearing permafrost from above and below, along with the corresponding rates of methane release into the surrounding permeable fractured-porous medium and gas migration channels or faults, have been studied. To investigate degradation from above, several temperature values at the upper boundary of the frozen layer were considered, including both positive and negative values in degrees Celsius. This allowed for the separate assessment of the contributions of heat and salinity to the degradation rates, as well as to evaluate the role of osmotic forces. To investigate degradation from below, several values of heat flow caused by the geothermal gradient were considered. As an application of the model, the results of calculations for the degradation rates of the frozen hydrate-bearing layer, following the onset of ocean transgression on the Arctic shelf approximately 10 thousand years ago, are presented.