Abstract: With the development of gas reservoir and gas condensate reservoir, the conventional study method of hydrocarbonwater phase behavior neglected the existence of water. Actually, with the advance of exploration and development for nature gas resource, the number of peculiar gas reservoir is increasing, such as unconventional high temperature、high pressure and low permeability gas reservoir. So high water content becomes a problem. In abroad, the phase behavior study for hydrocarbonwater phase behavior is becoming more and more important. Some achievements have challenged the conventional theory and method of hydrocarbon phase behavior. This paper discusses the newest study directions and achievements of hydrocarbonwater phase behavior from experiment facilities to study mechanisms, and presents some results achieved on gas condensate reservoir phase analysis with gaseous stratigraphic water, so that the petroleum engineers can use them to guide the oil and gas fields development.

Key words: phase behavior, hydrocarbonwater system, thermodynamics character, equation of state, phase equilibrium, phase diagram