As we all know, 0.8m3 water and 164 m3 gas will be produced when 1 m3 hydrate dissociates. When the dissociation happens in reservoir where pressure is up to 5~10 MPa around, how does the volume change? My results show that, in the condition of reservoir, the volume of gas will be much smaller than water's, as well as the original hydrate's. This wil lead to a great difference between gas saturation and water saturation when numerically simulating, which has confused me for a long time