| Summary: | New Zealand generates around 18% of its total electrical capacity using geothermal sources and could benefit significantly from simulation for optimization (Ministry of Business, Innovation & Employment, 2017). Current geothermal reservoir and process simulations are conducted separately with data manually parsed between the different simulators. Delays in the modelling process and the inability to efficiently model effects that reservoir changes over the asset’s lifetime have on the plant could lead to poor investment decisions and a lack of optimization. Integrating both reservoir and process simulators would enable accurate prediction of both reservoir and plant issues. In this paper, a proof of concept is developed. The reservoir simulator AUTOUGH is integrated with the process simulator VMGSim using Python and PyTOUGH. A demonstration based on a plant in New Zealand was built. The plant involves three producers and injectors which are used to feed brine to and inject brine from a binary geothermal plant. The aim of this study is to demonstrate and compare the effects of integrating reservoir and plant models in predicted reservoir and performance. Geothermal fluid mass flow, pressure and temperature data is passed between AUTOUGH and VMGSim where both the wellbore and plant is simulated. Brine injection data is passed back to AUTOUGH. This cycle is run until either a simulated plant failure occurs or the simulation is terminated. In an ORC plant, typical failures relate to temperature drops in the geothermal fluid that lead to the inability to vapourize the working fluid used to power the turbines. As a result, plant changes are required to maintain production, which could reduce power generation or require drilling an additional production well. by integrating the simulators, CO2 depletion within the reservoir can be studied and the effects characterized. A reduction of CO2 produced for a binary plant promotes heat transfer but at the cost of increased pressure drop within the wellbore, and, as a ...
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