The phase equilibria of the N-2 + CO2 + H2O ternary system were determined at 308.15 K and 318.15 K under 8.0 MPa, 12.0 MPa, and 16.0 MPa. It was demonstrated that the solubility of N2 in the liquid phase increased with the increase of its mole fraction in the vapor phase at fixed temperature and total pressure, and the solubility increased with reducing temperature or increasing pressure at a fixed mole fraction of N-2 in the vapor phase. The dependences of the solubility of CO2 in the liquid phase on the mole fraction of CO2 in the vapor phase, temperature, and pressure are similar, but its solubility was much larger than that of N-2. The effect of + KCl + CaCl2 on the solubility of the gas mixture of N-2 and CO2 in water was also determined at 308.15 K and 8.0 MPa, and it was shown that the addition of the salt mixture reduced the solubility of the gases in water considerably due to the salting-out effect.