INJECTION OF A HYDRATE-FORMING GAS INTO A SNOW LAYER SATURATED WITH THE SAME GAS

摘要

The problem of injection of a hydrate-forming gas (methane) into a snow layer whose pores are initially saturated with the same gas is solved. Self-similar solutions describing the temperature and pressure fields and the snow, hydrate, and gas distributions in the layer are constructed. It is shown that, depending on the initial thermobaric state of the snow-methane system and the rate of gas injection, three characteristic zones can be distinguished in the filtration region: a near zone, in which snow is completely converted into hydrate and, consequently, the hydrate layer is saturated with gas; an intermediate zone, in which gas, snow, and hydrate are in phase equilibrium; far zone filled with gas and snow. It is shown that the length of the heated zone decreases with increasing initial snow content in the layer and with decreasing injected gas pressure. It is also shown that the length of the region of hydrate formation increases with increasing permeability. It is noted that the heating of the intermediate zone occurs more rapidly.