Sebastian Held

Karlsruhe Institute of Technology | KIT · Institute of Applied Geosciences

Raw material extraction from geothermal fluids often comprises concentrating and cooling steps, which increases the risk of silica scaling formation. However, existing silica removal strategies do not consider the impact on raw material extraction. In this study, the applicability and element-selectivity of three silica removal techniques (seed-ind...

In the present study, we combined stable isotopes and anthropogenic tracers to investigate the origin, residence times, and evolution of thermal waters in the Lonquimay-Tolhuaca Volcanic Complex (LTVC) of the southern Chilean Andes. A total of 20 water samples from springs discharging at a broad range of temperatures (8–96°C) were collected and ana...

The BrineMine Project is a German-Chilean multidisciplinary research project realized by research and industry partners. The focus is developing strategies for raw material and water extraction from geothermal springs (Brine Mining) in Chile. The topics can be separated into a geological/geochemical part and a mechanical engineering part, which are...

The BrineMine project is a 3-year BMBF-funded research project that scientifically investigates the material use of geothermal water. The project is a bi-national research project between German and Chilean research and industry partners. The project is divided into two main topics: 1) Determination of the potential of thermal waters with regard to...

The inaccessibility of geological reservoirs, both for oil and gas production or geothermal usage, makes detection of reservoir properties and conditions a key problem in the field of reservoir engineering, including for the development of geothermal power plants. Herein, an approach is presented for the development of messenger nanoparticles for t...

Preferential fluid pathways along regional fault systems are crucial for the spatial localization of volcanic and geothermal manifestations. Differences in electric properties of fluids and hydrothermal alteration products against the unaltered matrix allow for visualization of such pathways. Unfavorable geometry for 2-D inversion resulting from th...

For successful geothermal reservoir exploration, accurate temperature estimation is essential. Since reservoir temperature estimation frequently involves high uncertainties when using conventional solute geothermometers, a new statistical approach is proposed. The focus of this study is on the development of a new multicomponent geothermometer tool...

In this work, the propagation of a thermal-hydraulic front caused by cold fluid injection is investigated, using a finite element (FE) model. The objective is to simulate the propagation of temperature changes in the subsurface and to quantify the resulting thermally induced stresses. The model is based on the setup of a geothermal powerplant in th...

For a successful geothermal reservoir exploration, an in-situ temperature estimation is essential. Since geothermometric reservoir temperature estimations using conventional solute geothermometers often entail high uncertainties, a new computational approach is proposed. The goal was to obtain high-accuracy multicomponent reservoir temperature esti...

In this work, the propagation of a thermal-hydraulic front caused by cold fluid injection is investigated, using a finite element (FE) model. The objective is to simulate the propagation of temperature changes in the subsurface and to quantify the resulting thermally induced stresses. The model is based on the setup of a geothermal powerplant in th...

Boreholes under dynamic conditions are a highly non-linear and complexly coupled thermo-hydraulic system. Multiple parameters, for instance, temperature, pressure, specific heat, enthalpy, viscosity, flow regime, heat transfer, degassing, steam quality and salinity are inter connected. Production and injection often entail several engineering chall...

For a successful geothermal reservoir exploration, an in-situ temperature estimation is essential. Since geothermometric reservoir temperature estimations often entail high uncertainties, statistical approaches are used. The focus is on the application of sensitive analyses on a basalt specific mineral set as multicomponent geothermometer to estima...

Geothermal brines with high CO2-contents require special treatments during the production of geothermal energy. Released into the atmosphere, the high emissions can cause a worse environmental damage for geothermal energy than for energy derived by the usage of fossil fuels (Aksoy et al. 2015). Besides the environmental impact, the CO2 also negativ...

The poster shows the application of multicomponent geothermometry to estimate the reservoir temperature in Krafla and Námafjall geothermal fields (Iceland) and the validation of the method by comparing the estimations to in-situ temperature measurements of the reservoir.

The Lonquimay-Tolhuaca volcanic complex and its surrounding area host several geothermal surface manifestations, including fumaroles, thermal springs, and bubbling pools. Previous studies have shown that fault systems with different orientations exert an important control on the chemical composition of thermal springs in the area. However, fundamen...

Solute geothermometry often leads to a broad range and often inconsistent calculated reservoir temperatures, in particular when exploring geothermal systems, where only limited information (geology, borehole data etc.) is available. The application of different Na-K and SiO2 geothermometer, the most widely used methods, not uncommonly lead to devia...

Besides temperature, mineralogy, residence time and dilution are crucial for assessing water-rock interaction intensity. The geothermal system at the Villarrica-Quetrupillán-Lanín volcanic chain, Southern Chile, is located across a prominent lithological transition from plutonic rocks of the North Patagonian Batholith (NPB) to volcano-sedimentary u...

The determination of reservoir temperatures represents a major task when exploring geothermal systems. Since the uncertainties of classical solute geothermometry are still preventing reliable reservoir temperature estimations, we assess the performance of classical geothermometers and multicomponent geothermometry by applying them to fluids compose...

In the following two chapters, we demonstrate how the numerical simulation can be applied to actual reservoir analysis. The first case study is given for the Groß Schönebeck research site in Germany, which represents a hot sedimentary aquifer type of EGS reservoirs. Input files for the simulations are available from https:// docs. opengeosys. org/...

This chapter presents several benchmark examples for demonstrating basics of how to set up OpenGeoSys input files for EGS reservoir modeling and check simulation results mainly using ParaView. Meshes are prepared using Gmsh. Readers can find more benchmark examples in the following materials

This chapter briefly glances at the basic theory of enhanced geothermal reservoir modeling, specifically hydraulic and thermal processes in fractured geological systems, and their numerical solutions with the finite element method.

Software used in the later benchmark examples and case studies are introduced. All of them are open-source and freely available for scientific research purposes.

The second case study is given for Soultz-sous-Forêts site in France, which represents an enhanced hydrothermal type of EGS reservoirs. Input files for the simulations are available from https:// docs. opengeosys. org/ books/ geoenergy-modeling-iii. Please note that the Soultz data provided can only be used for the scope of this tutorial book and t...

Welcome to the third volume of the Geoenergy Modeling series. This volume will introduce the reader to the field of modeling enhanced geothermal reservoirs. In this first chapter, we will briefly introduce Enhanced Geothermal Systems (EGS) and its reservoir modeling.

The Villarrica-Quetrupillán-Lanín volcanic chain is surrounded by > 20 hot springs, located on the flanks and in the valleys around the volcanos. The hot springs that are extensively used for spa purpose discharge thermal water of intermediate temperatures (27° – 81°C), mostly alkaline pH and low mineralization. To investigate fluid origin and gene...

Exploring a geothermal system the determination of reservoir temperatures is a major task. Unfavorably, the uncertainties of classical solute geothermometry are still large preventing reliable reservoir temperature estimations. In this study results of laboratory experiments are presented, equilibrating two reservoir rock analogues from the Villarr...

Using abandoned wells from oil and gas industry or dry holes, geothermal single well applications enable the prevention of drilling costs and prospecting risks which are crucial inhibitions in geothermal development. Recently, deep geothermal single wells were numerically investigated for their thermal and hydraulic performance. For the first time,...

This book focuses on numerical modeling of deep hydrothermal and petrothermal systems in fractured georeservoirs for utilization in Geothermal Energy applications. The authors explain the particular challenges and approaches to modeling heat transport and high-throughput flow in multiply fractured porous rock formations. In order to help readers ga...

The potential to provide base-load electricity as well as industrial and domestic heat places geothermal energy in a unique position in the future energy mix. As estimated by the International Energy Agency, geothermal power can contribute to 3.5% to the worldwide power and 3.9% to heat production by 2050. This includes the development of Enhanced...

Chile has a huge potential for the utilization of geothermal energy that is mostly associated with active volcanism. This resource has remained largely untapped so far but efforts on geothermal exploration have been increased recently. In the vicinity of Mt. Villarrica a variety of hot natural springs occur which manifest a complex geothermal syste...

Near Villarrica volcano, located in southern Chile, a high number of thermal springs indicate moderate geothermal activity with reservoir temperatures between 80 and 140 °C. Although being one of the most active volcanoes in Chile, high temperature geothermal manifestations are not observed. Moreover, the area is characterized by a complex tectonic...

Mid-crustal conductors are a common phenomenon in magnetotelluric studies. In the Andean Cordillera of southern Chile they appear to concentrate along major fault zones. A high-resolution, broad-band magnetotelluric survey including 31 stations has been carried out along two profiles perpendicular to (1) the Liquiñe-Ofqui Fault Systems (LOFS) and (...

Geothermal systems are often related to active volcanic areas forming typical high-enthalpy geothermal reservoirs. However at Mt. Villarrica the processes active in the subsurface do not favor the formation of high-enthalpy geothermal reservoirs. Geophysical and geochemical investigations demonstrate the importance of major faults governing fluid f...

The EGS pilot project in Soultz-sous-Forêts, is now operated by an industry consortium, heading for optimal reservoir management. A 3D thermo-hydraulic numerical model, based on a complex geological model of the reservoir is presented with the goal to determine input parameter for an economic analysis, comparing reservoir management based on leveli...