Description: This deliverable summarizes the activities related to the development of predictive models to simulate the impact of fluid flow hydrodynamics and chemical composition uncertainties on the production behavior of geothermal assets. Specifically, in this report, the mineral precipitation behavior of the geothermal fluid was studied as both uncertainties in the fluid composition and the interaction between the fluid flow hydrodynamics and mineral precipitation can impact the deposition of the scaling. A workflow was developed to couple a multiphase flow solver to thermodynamics libraries and models which are used to simulate the precipitation amount and kinetics of different geothermal minerals. This coupled workflow will enable a better estimation of the location and amount of precipitated minerals in different location of a geothermal system. A detailed roughness model was developed to simulate the impact of mineral deposition to the fluid flow. In addition, an uncertainty quantification workflow was combined with the modelling framework to estimate the uncertainty bounds of the scaling and precipitation resulted from uncertainties in the fluid composition characterization and operational settings. The modelling and uncertainty quantification workflow was demonstrated on a barite precipitation case study in a heat exchanger. Initially, the impact of geo-chemical uncertainties (in fluid composition) on the mineral precipitation was assessed. Afterwards, the coupled fluid flow and precipitation model with the developed roughness model was tested. Finally, the coupled uncertainty quantification workflow with the coupled model was simulated to assess the impact of fluid composition uncertainties on mineral deposition. As an outcome of the simulation, the impact of uncertainties in the mineral deposition on reduction in the production rate and heat transfer (within the heat exchanger) was calculated. The developed framework is flexible and generic which can be applied to various production and operational challenges in geothermal assets. In the future, the workflow can be used to optimize the design and operation of geothermal assets considering various sources of uncertainties which is not only fluid composition but also operational conditions (link to D4.5 REFLECT), robust modelling of other geo-chemical and flow assurance challenges in geothermal sites or even developing geo-chemical risk maps for different sites within EU (link to WP3 REFLECT).

Description: The efficiency and feasibility of geothermal utilisation depends strongly on the characteristics and behaviour of the fluids that transfer heat between the geosphere and the engineered components of a power plant. Chemical and physical processes such as precipitation, corrosion, or degassing are induced by pressure and temperature changes, with potentially serious consequences for power plant operation and project economics. The EU Horizon 2020-funded project REFLECT aims to avoid such problems by collecting high-quality chemical, physical, and microbiological data at extreme salinities, pressures or temperatures and improving the understanding of kinetic processes through laboratory experiments. These data are presented in a European geothermal fluid atlas and implemented in predictive models in order to provide recommendations on how to best operate geothermal systems for a sustainable future.

Description: This deliverable summarizes the optimization workflow to determine the optimum operational controls for the geothermal assets operation considering the uncertainties in the brine composition. The developed models for coupling hydrodynamics with chemistry and uncertainty quantification workflow for estimating the risk of scaling in geothermal plants were integrated with a stochastic optimization model. Results showed the demonstration of such an integrated workflow applied to a scaling precipitation case study and possible variations in operational decisions due to uncertainties in the brine composition.

Description: This document presents the application of coupled hydrogeochemical codes to the modelling of geothermal fluid reactivity in tubings during the production of geothermal energy. Two codes are used on two examples of fluids: one is very concentrated with a moderate temperature (no phase changes during the pumping) and one hot fluid with a lower salinity (with phase change). Results focus on the risks of scaling during the exploitation.