Keyword: «underground gas storage»

In this work, the equilibrium conditions of the natural gas hydrate formation in porous media are experimentally studied to determine the boundary of the hydrate stability zone in 2 areas of the Vilyui syneclise. It has been established that the lower boundaries of the stability zone of natural gas hydrates in a moist unsalted porous medium are located at a depth of 1120 m. When the samples are saturated with mineralized water, the boundaries are located 30–40 m higher. The obtained experimental results allow us to conclude that in subpermafrost aquifers of the Vilyui syneclise has favorable conditions for the formation of natural gas hydrates.

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.