Clathrate phase equilibria for two ternary water + deuterium oxide + carbon dioxide and water + deuterium oxide + chlorodifluoromethane (R22) systems were measured at several different mass % of water and deuterium oxide mixtures. Equilibrium dissociation pressures of these two ternary systems at the three-phase (clathrate-liquid-vapor) boundaries range (1.43 to 4.86) MPa and (0.141 to 0.886) MPa, respectively. The temperature range occupied by the three-phase boundary of the water + deuterium oxide + R22 system is a little larger than that of the water + deuterium oxide + carbon dioxide system. The dissociation pressures at the quadruple points were found to steadily increase with deuterium oxide composition.