MODELLING TRACERS USING THE WAIWERA GEOTHERMAL FLOW SIMULATOR

Abstract

The Waiwera parallel, open-source geothermal flow simulator now includes the ability to model the movement of passive tracers in geothermal flows. A new algorithm is used which offers greater flexibility and higher efficiency. Rather than creating special
equation-of-state modules for tracers, the tracer equations are solved separately from the flow equations, and as they are linear, this can be done using only a single linear equation solution per time step. This approach also allows arbitrary numbers of tracers to be
modelled in conjunction with any equation of state. Either liquid-phase or vapour-phase tracers can be simulated, and temperaturedependent Arrhenius decay can be included.
In this paper we describe Waiwera`s new tracer capabilities and demonstrate their performance via benchmark test problems and by application to a field-scale geothermal reservoir model.