Gas hydrate formation for mixtures of methane plus helium and ethane plus helium

Equilibrium conditions of gas hydrates formed from methane + helium and ethane + helium mixtures are experimentally determined. As the helium concentration in gas mixtures increases, the equilibrium conditions shift to lower temperatures and higher pressures. The experimental data agree with the calculated values from model prediction having the assumption that helium molecules in a hydrate lattice do not contribute to the hydrate stability of gas mixtures. It is suggested that helium rarely contributes to the stability of the gas hydrate at experimental pressures < 10 MPa.