Gas Hydrate Formation by Methane-Helium Mixtures

Equilibrium conditions for gas hydrates formed by methane-helium mixtures with helium concentrations of 31.9, 63.9, and 74.6 mol.-% have been studied at pressures up to 160 bar. The data obtained indicate that in the studied range of helium concentrations and pressures helium hardly contributes to the stability of the gas hydrate formed. The shift of equilibrium conditions to lower temperatures and higher pressures is caused by dilution of methane in the gas phase and, consequently, the decrease in the chemical potential of methane in the gas phase.