Technology for development of methane-hydrate deposits jointly with receiving fresh water.
Yuriy P. Denysov, Vasyl V. Klymenko, Victor V. Martynenko, Czesław Rybicki
Vol. 34, no. 2 (2017), s. 531-541, 
The technology of development of bottom gas-hydrate deposits, which allows to receive fresh water simultaneously with methane, is presented. Principal schemes are presented and methods of operation of dual-purpose plants implementing this technology and described on the basis of the methods of gas production from methane hydrates that are most prepared for practical implementation: 1) injection of warm water into the well; 2) depressive effect on the deposit; 3) replacement of methane in hydrates with carbon dioxide injected into the reservoir. The magnitude of the decrease in temperature with the depression effect on the deposit is determined. It is shown that, the amount of fresh water obtained in dual-purpose plants operating with the replacement of methane in hydrates with carbon dioxide is proportional to the coefficient of the recycling rate of CO₂. For the considered schemes of dual-purpose plants, processes of decomposition of methane hydrates in the gas-hydrate formation are analyzed, an exergic efficiency estimation is performed. Such installations. The economic efficiency of a single-purpose and dual-purpose gas-producing units operating according to an approved method of depression is considered. It is shown that the most effective are dual-purpose facilities operating using the method of methane replacement in hydrates with carbon dioxide, and the coefficients of economic efficiency of dual-purpose installations are at least 1.2 times higher than similar coefficients of single-purpose gas production facilities.