Mathematical Modeling of Carbon Dioxide Injection into a Reservoir with Methane and Water Taking into Account the Formation of Carbon Dioxide Hydrate

Abstract

An increase in the concentration of carbon dioxide in the atmosphere caused by the combustion of fuels has a negative impact on the current biosphere of the Earth. One way to get rid of excess carbon dioxide in the atmosphere is to capture and store it. Various methods for long-term storage of carbon dioxide are proposed, including in various geological formations in gas hydrate form, since gas hydrates have a number of unique properties, for example, it is possible to stably store a sufficiently large amount of gas in a small volume at a relatively low pressure. One of the objects for creating underground carbon dioxide storage facilities are depleted natural gas deposits, since they are well studied, the characteristics of the deposits, their geometric dimensions are known, and there are drilled wells. To study the patterns of the formation process of an underground gas hydrate carbon dioxide storage, the article presents a mathematical model of the process of carbon dioxide injection into a zonally heterogeneous porous reservoir, initially saturated with methane and water, accompanied by the formation of gas hydrate. Unlike previous works, the mathematical model additionally takes into account a number of factors: the solubility of carbon dioxide in water, zonal heterogeneity of a reservoir, heat exchange of the reservoir with the surrounding rocks impermeable to matter, filtration of water and gas. Numerical solutions of the problem were constructed to describe the distribution of parameters (pressure, temperature, carbon dioxide hydrate saturation) in the reservoir.