The theory of injection of liquid carbon dioxide in formation, saturated system “hydrate of methane–methane” in the mode of formation of the intermediate melt zone

The scheme and the corresponding theoretical model of process of methane replacement by liquid carbon dioxide at his injection in a gas hydrate layer are offered. The flat one-dimensional automodel solution corresponding to injection of carbon dioxide in semi-infinite layer through flat border is constructed. It is fixed that such solution can contain three characteristic zones in general case: the far zone, where there is a methane filtration in the porous medium which is partially saturated by methane hydrate in the absence of phase transitions; the melted zone of products of decomposition of methane hydrate (water and methane) can be formed in the intermediate zone (this zone is formed because of heating owing to injection of warm carbon dioxide); the near zone where there is a filtration of liquid carbon dioxide in the layer which is partially saturated by hydrate of carbon dioxide. The analysis of influence of parameters of layer, his initial state (temperature, pressure and hydrate saturation) and the parameters of the injected dioxide of carbon on the various modes of filtration is conducted.