Extending the persistent primary variable algorithm to simulate non-isothermal two-phase two-component flow with phase change phenomena

Yonghui Huang,Olaf Kolditz,Haibing Shao

doi:10.1186/s40517-015-0030-8

Abstract

Abstract In high-enthalpy geothermal reservoirs and many other geo-technical applications, coupled non-isothermal multiphase flow is considered to be the underlying governing process that controls the system behavior. Under the high temperature and high pressure environment, the phase change phenomena such as evaporation and condensation have a great impact on the heat distribution, as well as the pattern of fluid flow. In this work, we have extended the persistent primary variable algorithm proposed by (Marchand et al. Comput Geosci 17(2):431–442) to the non-isothermal conditions. The extended method has been implemented into the OpenGeoSys code, which allows the numerical simulation of multiphase flow processes with phase change phenomena. This new feature has been verified by two benchmark cases. The first one simulates the isothermal migration of H 2 through the bentonite formation in a waste repository. The second one models the non-isothermal multiphase flow of heat-pipe problem. The OpenGeoSys simulation results have been successfully verified by closely fitting results from other codes and also against analytical solution.

Highlights

In deep geothermal reservoirs, surface water seepages through fractures in the rock and moves downwards
We have extended the persistent primary variable algorithm proposed by (Marchand et al Comput Geosci 17(2):431–442) to the non-isothermal conditions
The extended method has been implemented into the OpenGeoSys code, which allows the numerical simulation of multiphase flow processes with phase change phenomena

Summary

Introduction

Surface water seepages through fractures in the rock and moves downwards. Under the high temperature and pressure condition, water vaporizes from liquid to gas phase. It will condensate back into the liquid form and release its energy in the form of latent heat Often, this multiphase flow process with phase transition controls the heat convection in deep geothermal reservoirs. This multiphase flow process with phase transition controls the heat convection in deep geothermal reservoirs Such multiphase flow and heat transport are considered to be the underlying processes in a wide variety of applications, such as in geological waste repositories, soil vapor extraction of Non-Aqueous Phase Liquid (NAPL) contaminants (Forsyth and Shao 1991), and CO2 capture and storage (Park et al 2011; Singh et al 2012).

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Discussion

Conclusion