Abstract
Multiphase flows that arise in geothermal energy development have been briefly reviewed. A particular emphasis is placed on gas-liquid two-phase flows in geothermal production well. A liquid phase geothermal fluid is normally fed at the bottom of the well. However, as the fluid rises in the wellbore, it loses the pressure and eventually starts boiling; a steam-water two-phase flow results. A one-dimensional formulation of the two-phase flow for wellbore simulation is described in some detail, where the steam-water relative velocity is taken into account through empirical correlations. The presence of dissolved NaCl and noncondensable gas (CO2) is. one characteristic of geothermal fluid. The present status of two-phase flow simulators for production wellbore is also described. It is suggested that the empirical correlations to differentiate flow regimes and to evaluate the frictional pressure losses along the well, especially for large diameter pipe flows, are essential in accurate prediction of the wellbore two-phase flows.
