An isenthalpic formulation for simulating geothermal systems with phase changes

Abstract

We propose a unified isenthalpic formulation for the equilibrium problem of compositional multiphase mixtures. To solve the equilibrium problem numerically, we used an interior point method with line search and present an example of how the unified isenthalpic formulation can be used to model water and carbon dioxide as binary mixtures. A connection is made between the isenthalpic equilibrium problem and the overall composition formulation of mass and energy conservation equations. As part of this research, mass and heat transfer simulations are being conducted in geothermal reservoirs.