The interfacial properties of the N2 + H2O and N2 + H2O + silica systems were investigated (in the temperature range of 313–448 K and at pressures up to 50 MPa) by using extensive molecular dynamics simulations. The simulated interfacial tension (IFT) of the N2 + H2O system is in line with our density gradient theory predictions based on the cubic-plus-association equation of state and experimental data. These IFTs decrease with increasing pressure and temperature. The effects of pressure on these IFTs are less pronounced at high temperature. Here, the positive surface excess of N2 explains the decreasing behavior of the IFT as a function of pressure. It can be seen that the surface excess of N2 is reduced as the temperature is raised. This explains the less pronounced effects of the pressure on the IFTs at high temperature. The simulated water contact angle (CA) of the N2 + water + silica system is in the range of 38.6–54.5°. An important finding is that under the studied conditions, these water CAs are not strongly influenced by temperature and pressure. Here we find that the effects of the IFT between H2O and N2 are more pronounced on the adhesion tensions. The IFT between silica and H2O is found to be much lower than that between silica and N2 under all conditions. Negligible amounts of N2 were found to be adsorbed at the interface between the droplet and the silica surface. The relatively higher capillary pressure of the N2 + H2O + silica system indicates that the presence of N2 might be useful for the storage of CO2 in saline aquifers.