NUMERICAL MODELING OF NATURAL AND CARBON DIOXIDE HYDRATE FORMATION DURING INJECTION OF THESE GASES INTO A SUBPERMAFROST WATER-SATURATED FORMATION

The article presents the results of a computational experiment aimed at obtaining criteria for selecting geological
structures for creating an underground natural gases storage facility and burial carbon dioxide in a hydrated
state in subpermafrost aquifier. A mathematical model of gas injection through a single well into a horizontal
water-saturated formation under permafrost rocks is presented, which takes into account all the main physical and
thermodynamic features of the hydrate formation process. A comparison of the calculation results for the dynamics
of distribution of temperature, pressure, water saturation, and hydrate saturation is carried out. Examples of
numerical calculation of gas injection into a formation with an initial water saturation of 0.9, porosity of 0.15, and
permeability of 8·10 ^–13 m ² are considered. The variable parameters are the volumetric flow rate of the injected gas
and equilibrium conditions of hydrate formation. The influence of the equilibrium conditions of hydrate formation
on the main indicator of the process efficiency — hydrate saturation of the created storage facility — is shown. The
results of laboratory experiments to determine the equilibrium conditions for the formation of hydrates of natural
and carbon dioxide gases in porous media and in aqueous solutions simulating formation waters of subpermafrost
horizons were used to conduct computational experiments. It was revealed that for the creation of an underground
storage facility, it is preferable to choose a formation with a sodium bicarbonate type of water, rather than with
fresh water

Author:  I. I. Rozhin, G. I. Ivanov
Keywords:  underground gas storage facility, natural gas, carbon dioxide, gas hydrate, hydrate formation, multiphase nonisothermal filtration, computational experiment
Page:  1465