Knowledge of phase behavior of fluids and gases in a petroleum reservoir becomes increasingly critical when pressures change and abundances of gas and oil change as the reservoir is produced. The pressure, volume, temperature relationships are needed to understand these changes in fluid composition and pressure evolution. In particular, as the producers considers improved oil recovery techniques, the fluid properties are integral part of the reservoir characterization.
PVT relationships are divided to dry gases, wet gases, gas condensates, volatile oils, and black oils. GEMINI efforts to date have focused on development of correlations between standard measured properties of black oil, dry gas, and water. Oil calculations include Oil Formation Volume Factor, Coefficient Of Isothermal Compressibility, and Dead and Saturated Oil Viscosities calculations. Water calculations include Compressibility of Brine and Viscosity of Water. Gas calculations include Gas Formation Volume Factor, Gas Compressibility and Gas Viscosity calculations.