Keyword: «gas hydrate»

The work is devoted to a mathematical modeling of the decomposition of natural gas hydrate in compacted sand samples under decompression. The 1D mathematical model of the process includes equations of mass and heat balance, equation of gas state, equation of gas flow and empirical dependencies related to the kinetics of hydrate dissociation in a porous medium. An empirical dependence of the equilibrium pressure of natural gas hydrate on temperature in a porous medium is used. As a result of the simulation, the distributions of the main physical parameters in the sample and their evolution over time were obtained.

Mathematical modeling methods assess the possibility of natural gas storage by converting them to a hydrate state when gas is injected into permafrost aquifers. The model of multiphase nonisothermal filtration takes into account the main physical features of this process, including gas compressibility, the Joule-Thomson effect, adiabatic expansion, joint movement of water and gas, mass transfer between gas, water and a hydrate. To conduct computational experiments, the results of laboratory experiments of the equilibrium conditions of the natural gas hydrates formation in a free volume and in a porous medium saturated with water and aqueous solutions of sodium bicarbonate were used. The influence of phase equilibrium conditions on the main indicator of the process efficiency – the hydrate saturation of the created storage is studied.

This paper analyzes gas hydrate technologies for supplying gas to the Arctic regions of the Republic of Sakha (Yakutia). An experimental study of the hydrates formation and decomposition in bulk water and salt solutions of different concentrations demonstrated the feasibility of using gas hydrate technology for the accumulation, storage, and transportation of natural gas under the region's climatic conditions and existing transport infrastructure. Experiments demonstrated the concentration of C2-C4 hydrocarbons in the hydrate phase during hydrate formation in salt solutions, leading to an increase in the fat content and calorific value of the original gas. It is shown that the cold climatic conditions of the Arctic regions of the Republic of Sakha (Yakutia) allow to use gas hydrates as an additional energy source.