Two-phase flow in geopressured geothermal wells

Abstract

The production characteristics of two-phase (free methane and liquid water with dissolved methane) geopressured geothermal wells are analyzed. The fluid flow in the aquifer is treated as single-phase (liquid water with dissolved methane) unsteady radial Darcian flow; two-phase flow is assumed to occur only in the cased part of the production hole. The mathematical model allows for different gas and liquid velocities in the two-phase regime. Sample calculations illustrate the effects on production of aquifer permeability and compressibility, the depth of the geopressured aquifer, the reservoir temperature, and the dissolved methane content of the aquifer fluids.