Study of hydrates formation in mineralized solutions and kinetic regularity of their decomposition

Abstract

Processes of hydrate formation in water solutions of electrolytes that imitating the composition of reservoir water of eastern Siberian platform were studied. The investigation of hydrates properties, obtained from mineralized solutions showed notable influence of electrolytes on the processes of their growth and decomposition, as well as texture and component composition of gases in hydrates. Equilibrium conditions of hydrate formations in solutions of electrolytes shifted to the field of higher pressures and lower temperatures. The texture of the hydrates depends on the type of cation in the electrolyte solutions. If filiform crystals of hydrates are formed in the water, sodium cations promote to the formation of granular forms and calcium does to the formation of laminate hydrates. The research of the component composition of the gas obtained by the decomposition of hydrates showed that the mineralization of solutions leads to the concentration of hydrocarbons C2-C4 in clathrate phase and to increasing of the fatty coefficient. The shape of the kinetic curves of hydrate decomposition depends on the type and mineralization degree of the model reservoir waters.