Articles

Thermal resistance of borehole heat exchangers composed of multiple loops and custom shapes

The thermal resistance of a borehole can be reduced by employing thermally enhanced grout, increasing the surface area of the loop and locating the legs proximal to the bore wall. Thermal models that are used ...

Authors: AA Koenig

Exploration for deep geothermal reservoirs in Luxembourg and the surroundings - perspectives of geothermal energy use

The aim of this paper is to combine different types of information necessary for a first rather qualitative assessment of deep geothermal reservoirs in the region of Luxembourg. Within the geological framework...

Authors: Tom Schintgen

How do permeable fractures in the Triassic sediments of Northern Alsace characterize the top of hydrothermal convective cells? Evidence from Soultz geothermal boreholes (France)

The thermal regime of the Upper Rhine Graben (URG) is characterized by a series of anomalies near Soultz-sous-Forêts (France), Rittershoffen (France), and Landau (Germany). These temperature anomalies are asso...

Authors: Jeanne Vidal, Albert Genter and Jean Schmittbuhl

Designing coaxial ground heat exchangers with a thermally enhanced outer pipe

Ground heat exchangers installed in boreholes are an expensive component of a ground-coupled heat pump system, where minimizing the borehole length with appropriate materials and configuration can reduce the o...

Authors: Jasmin Raymond, Serge Mercier and Luc Nguyen

Thermal response test for shallow geothermal applications: a probabilistic analysis approach

Thermal Response Test (TRT) is an onsite test used to characterize the thermal properties of shallow underground, when used as heat storage volume for shallow geothermal application. It is applied by injecting...

Authors: Francesco Tinti, Roberto Bruno and Sara Focaccia

Hydrochemical characterisation of a major central European heat flux anomaly: the Bürchau geothermal spring system, Southern Black Forest, Germany

The possible signature of deep fluids originating from processes occurring during infiltration or circulation in a remote valley in the Black Forest (Germany), a typical infiltration area in the crystalline ba...

Authors: Julian Rolker, Eva Schill, Ingrid Stober, Jochen Schneider, Thomas Neumann and Thomas Kohl

Local stress anomaly in the Bavarian Molasse Basin

The characterization of fault zones in the Bavarian Molasse Basin plays a major role for further geothermal reservoir development. Hence, their identification, geological origin, and hydraulic characterization...

Authors: Robin Seithel, Ulrich Steiner, Birgit Müller, Christian Hecht and Thomas Kohl

Characterization of ambient seismic noise near a deep geothermal reservoir and implications for interferometric methods: a case study in northern Alsace, France

Ambient noise correlation techniques are of growing interest for imaging and monitoring deep geothermal reservoirs. They are simple to implement and can be performed continuously to follow the evolution of th...

Authors: Maximilien Lehujeur, Jérôme Vergne, Jean Schmittbuhl and Alessia Maggi

Uplift around the geothermal power plant of Landau (Germany) as observed by InSAR monitoring

Several centimetres of uplift were observed extending over a square-kilometre area around the geothermal site of Landau, Germany.

Authors: Christine Heimlich, Noël Gourmelen, Frédéric Masson, Jean Schmittbuhl, Sang-Wan Kim and Jérôme Azzola

Mechanical origin of b-value changes during stimulation of deep geothermal reservoirs

The distribution of induced-earthquake magnitudes in deep geothermal reservoirs is a classical tool for monitoring reservoirs. It typically shows some important fluctuations through time and space. Despite bei...

Authors: Arne Stormo, Olivier Lengliné and Jean Schmittbuhl

Recent studies on hydrothermal systems in China: a review

This paper reviews the state-of-the-art in hydrothermal systems in China with emphasis on current studies of potential and reservoir engineering. Three hydrothermal systems, namely, Yangbajing, Xianyang, and X...

Authors: Yanlong Kong, Zhonghe Pang, Haibing Shao, Shengbiao Hu and Olaf Kolditz

2D structural and thermal models in southeastern Norway based on the recently drilled Årvollskogen borehole and 2D density, magnetic and thermal modelling

We have made an attempt to understand the main mechanism which controls the conductive heat transfer in the Årvollskogen borehole. This has been done in order to determine the 2D subsurface temperature distrib...

Authors: Yuriy Petrovich Maystrenko, Harald Kristian Elvebakk, Guri Venvik Ganerød, Ole Lutro, Odleiv Olesen and Jan Steinar Rønning

Possible natural fluid pathways from gravity pseudo-tomography in the geothermal fields of Northern Alsace (Upper Rhine Graben)

This study aims on investigating the regional flow field of the Soultz and adjacent geothermal fields located on the western side of the central Upper Rhine Graben and thus to provide insight into the origin o...

Authors: Paul Baillieux, Eva Schill, Yassine Abdelfettah and Chrystel Dezayes

Reply to discussion on ‘Spectral analysis of aeromagnetic data for geothermal energy investigation of Ikogosi Warm Spring - Ekiti State, southwestern Nigeria’

In reply to Geothermal Energy 2:11 comments about possible errors in our recent paper Geothermal Energy 2:6, 1-21 with title ‘Spectral analysis of aeromagnetic data for geothermal energy investigation of Ikogo...

Authors: Ema Michael Abraham, Kolawole Muideen Lawal, Amobi Chigozie Ekwe, Owens Alile, Kehinde Ayofe Murana and Aminu Ahmed Lawal

Two-dimensional THM modelling of the large scale natural hydrothermal circulation at Soultz-sous-Forêts

A two-dimensional numerical model is developed for the Soultz-sous-Forêts reservoir from an idealized cross-section containing six homogeneous horizontal layers. The considered constitutive equations are those...

Authors: Vincent Magnenet, Christophe Fond, Albert Genter and Jean Schmittbuhl

Induced seismicity in EGS reservoir: the creep route

Observations in enhanced geothermal system (EGS) reservoirs of induced seismicity and slow aseismic slip ruptures on related faults suggest a close link between the two phenomena.

Authors: Jean Schmittbuhl, Olivier Lengliné, François Cornet, Nicolas Cuenot and Albert Genter

Hydrochemical properties of deep carbonate aquifers in the SW German Molasse basin

The Upper Jurassic (Malm) limestone and the Middle Triassic Muschelkalk limestone 18 are the major thermal aquifers in the southwest German alpine foreland. The aquifers 19 are of interest for production of ge...

Authors: Ingrid Stober

Discussion on `Spectral analysis of aeromagnetic data for geothermal energy investigation of Ikogosi Warm Spring - Ekiti State, southwestern Nigeria’

The recent paper by Abraham et al. (2014) `Spectral analysis of aeromagnetic data for geothermal energy investigation of Ikogosi Warm Spring - Ekiti State, southwestern Nigeria’ applied spectral analysis in th...

Authors: Levi Ikechukwu Nwankwo

The significance of hydrothermal alteration zones for the mechanical behavior of a geothermal reservoir

The occurrence of hydrothermally altered zones is a commonly observed phenomenon in brittle rock. The dissolution and transformation of primary minerals and the precipitation of secondary minerals affect rocks...

Authors: Carola Meller and Thomas Kohl

A simplified model for the estimation of life-cycle greenhouse gas emissions of enhanced geothermal systems

The development of `enhanced geothermal systems' (EGS), designed to extract energy from deep low-enthalpy reservoirs, is opening new scenarios of growth for the whole geothermal sector. A relevant tool to esti...

Authors: Martino Lacirignola, Bechara Hage Meany, Pierryves Padey and Isabelle Blanc

Physical property relationships of the Rotokawa Andesite, a significant geothermal reservoir rock in the Taupo Volcanic Zone, New Zealand

Geothermal systems are commonly hosted in highly altered and fractured rock. As a result, the relationships between physical properties such as strength and permeability can be complex. Understanding such prop...

Authors: Paul A Siratovich, Michael J Heap, Marlène C Villenueve, James W Cole and Thierry Reuschlé

Mapping the low enthalpy geothermal potential of shallow Quaternary aquifers in Finland

EU member states have concluded an agreement that renewable energy will cover 20% of the total energy production by 2020. To achieve this target, it is essential to investigate all possibilities for renewable ...

Authors: Teppo Arola, Lari Eskola, Jukka Hellen and Kirsti Korkka-Niemi

Inferring the in situ stress regime in deep sediments: an example from the Bruchsal geothermal site

Knowledge of the ambient state of stress is of crucial importance for understanding tectonic processes and an important parameter in reservoir engineering. In the framework of the 2,500-m deep geothermal proje...

Authors: Jörg Meixner, Eva Schill, Emmanuel Gaucher and Thomas Kohl

Spectral analysis of aeromagnetic data for geothermal energy investigation of Ikogosi Warm Spring - Ekiti State, southwestern Nigeria

Aeromagnetic data of the Ikogosi warm spring region was used to calculate the basal depth of the magnetic layer (Curie point depth) in the region. The warm spring issues from a crossing of fractures from a met...

Authors: Ema Michael Abraham, Kolawole Muideen Lawal, Amobi Chigozie Ekwe, Owens Alile, Kehinde Ayofe Murana and Aminu Ahmed Lawal

High-heat-producing granites of East Dharwar Craton around Gugi, Karnataka, and their possible influence on the evolution of Rajapur thermal springs, Deccan Volcanic Province, India

The thermal springs of Rajapur situated along the west coast of Maharashtra and parts of high-heat-generating granites of Gugi in Karnataka (India) seem to be genetically related. The present investigation inv...

Authors: Hemant K Singh, Yadvendra Kumar, Dornadula Chandrasekharam, Trupti Gurav and Banambar Singh

Thermal effect of a borehole thermal energy store on the subsurface

The thermal effect on the subsurface of a large borehole thermal energy store (BTES) has been investigated by coupling measured rock properties with an enhanced FEFLOW simulation.

Authors: Philipp Mielke, Dan Bauer, Sebastian Homuth, Annette E Götz and Ingo Sass

Thermodynamic pre-determination of power generation potential in geothermal low-temperature applications

Small capacity, low temperature, geothermal heat sources provide significant opportunities for distributed, small scale power generation. Project definitions and pre-dimensioning however require advanced therm...

Authors: Henrik Öhman and Per Lundqvist

Hydrochemistry and geothermometry of an Albian aquifer from Oued Righ region in northeastern Algerian Sahara

The area of Oued Righ is one of the important geothermal areas in northeastern Algerian Sahara. It is characterized by a hot arid climate with intense dryness and very high evaporation rates. These various cli...

Authors: Warda Chaib and Nacer Kherici

Three-dimensional thermal sensitivity analysis of cooling of a magma chamber in the Los Azufres geothermal field, Michoacán, Mexico

We present three-dimensional simulation of cooling of 63 models of a magma chamber in the Los Azufres geothermal field by varying the top of the chamber depth between 5 and 9 km (centroid from about 7 to 13 km...

Authors: Surendra P Verma and Efraín Gómez-Arias

A systematic review of enhanced (or engineered) geothermal systems: past, present and future

Enhanced (or engineered) geothermal systems (EGS) have evolved from the hot dry rock concept, implemented for the first time at Fenton Hill in 1977. This paper systematically reviews all of the EGS projects wo...

Authors: Katrin Breede, Khatia Dzebisashvili, Xiaolei Liu and Gioia Falcone

Thermal response test numerical modeling using a dynamic simulator

Borehole heat exchangers are a growing technology in the area of house/building air conditioning, most of all in northern Europe.

Authors: Sara Focaccia

Performance analysis and working fluid selection for geothermal energy-powered organic Rankine-vapor compression air conditioning

To utilize geothermal energy from hot springs, an organic Rankine cycle/vapor compression cycle (ORC/VCC) system was employed for air conditioning and a thermodynamic model was developed.

Authors: Xianbiao Bu, Lingbao Wang and Huashan Li

Geothermal Energy: a glimpse at the state of the field and an introduction to the journal

Authors: Olaf Kolditz, Leslie A Jakobs, Ernst Huenges and Thomas Kohl