Modeling Liquid Dominated Two Phase Flow in Geothermal Reservoirs in Vicinity to, and Inside Wells

Abstract

This paper describes a new modeling approach of two phase fluid flow in geothermal reservoirs. The flow is assumed to be liquid dominated with vapor traveling alongside the liquid if present, which is common for hydrothermal systems. The problem is governed by the Darcy-Forchheimer equation for fluid transport, along with a convective-diffusive energy equation. A special case arises inside wells, where the Forchheimer part of the flow equation becomes dominant and is quantified by using well known relations for fluid flow in pipes. The problem is formulated and solved by using a highly customizable set of C++ libraries and tools, collectively named OpenFOAM, along with the IAPWS-IF97 standard for the properties of steam and liquid water. Preliminary results from the modeling work are presented in simple case studies, showing the basic abilities of the programming platform to solve large three dimensional problems for flow in porous media. It is concluded that the modeling framework is very promising, since it is under constant improvement by a large group of developers and incorporates cutting edge technologies in numerical analysis for mathematical modeling.