Numerical simulation of hydrate formation at injection cold gas in the snow massif

The problem of the formation of hydrate in a snow massif, in the initial state saturated with gas, with the injection of the same gas is solved. The constructed mathematical model is based on the equations of continuum mechanics. For the axisymmetric formulation with an extended region of phase transitions, self-similar solutions are constructed that describe the temperature and pressure fields, as well as the saturation of snow, hydrate, and gas in the massif. The numerical solution of the problem was realized by the method of shooting. It is shown that, depending on the initial thermobaric state of the gas-ice system, as well as the intensity of gas injection, determined by its mass flow, three characteristic zones can be distinguished in the filtration area, differing in their structure and extent: near, in which the snow has completely passed to the hydrate, and therefore only the hydrate and gas phases are intermediate, in which the formation of hydrate from gas and ice occurs, and the distant gas, which is saturated with phases of gas and ice. The influence of the mass flow rate of the injected gas, the initial snow saturation and the initial temperature of the massif on the extent of the hydrate volume formation zone under negative temperature conditions, as well as on the temperature and hydration saturation at the boundary separating the near and intermediate zones is studied.