Article
Engineering, Geological
Omar Rodriguez Villarreal, Alberto Varela Valdez, Christian La Borderie, Gilles Pijaudier-Cabot, Moises Hinojosa Rivera
Summary: This study utilized an energy balance-based method to investigate fracture parameters in hydraulic fracturing tests, revealing an increase in fracture energy with heating.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Thermodynamics
Ziwang Yu, Xiaoqi Ye, Yanjun Zhang, Ping Gao, Yibin Huang
Summary: This study investigates the variation of thermal conductivity with saturation of rock samples from different basins in China. The correlations between saturation, porosity, internal structural characteristics, and thermal conductivity are examined. Improved models and a fitted model are proposed based on classical models and the relationship between porosity, saturation, and thermal conductivity. The models are evaluated and compared using error analysis. The study also includes a simulation of unsaturated rock with a single fracture heat transfer model. The findings provide theoretical support for accurate heat transfer calculations in geothermal engineering applications.
Article
Green & Sustainable Science & Technology
Musa D. Aliyu, Rosalind A. Archer
Summary: This paper presents a new three-dimensional numerical model of a hot dry rock geothermal reservoir and analyzes two case studies to determine the impact of different factors on reservoir performance, showing that wellbore placement significantly affects reservoir performance.
Article
Geochemistry & Geophysics
Martin Balcewicz, Benedikt Ahrens, Kevin Lippert, Erik H. Saenger
Summary: Research into clean and renewable energy solutions has highlighted the potential of geothermal energy, particularly in carbonate formations in Bavaria and NRW. The study emphasized the importance of focusing on fracture networks and orientations in order to optimize fluid flow in geothermal applications.
Article
Geochemistry & Geophysics
Sanem Elidemir, Nilgun Gulec, Kiymet Deniz, Yusuf Kagan Kadioglu
Summary: The reservoir lithology of the Edremit geothermal field in western Anatolia was analyzed using mineralogic-petrographic and geochemical analyses. The study identified the dominant rock fragments as granitic rocks and characterized the mineral phases present. The research also revealed the effects of cataclasis and alteration, indicating faulting and hydrothermal fluid activity. The findings suggest the presence of potential passageways for the fluid and the importance of geochemical studies in geothermal exploration.
APPLIED GEOCHEMISTRY
(2022)
Article
Geochemistry & Geophysics
Edith Sotelo, J. German Rubino, Santiago G. Solazzi, Nicolas D. Barbosa, Klaus Holliger
Summary: The study assesses the impact of damaged zones surrounding fractures on reflectivity and compliance, showing that the presence of damaged zones can enhance seismic reflectivity and normal compliance of fractures. This suggests that in largely impermeable environments, the seismic visibility of fractures can be improved through fluid pressure diffusion enabled by the presence of damaged zones.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Haitao Wang, Lijuan Wang, Zude Cheng
Summary: The heat extraction performance of an enhanced geothermal system (EGS) was simulated using COMSOL software. The effects of six factors, including thermal conductivity, matrix permeability, fracture width, injection temperature, injection flow rate, and the number of wells, on the heat extraction performance of the EGS heat reservoir over a 40-year period were analyzed. The results indicate that matrix permeability and injection flow rate are the main factors affecting the heat production performance of the EGS geothermal reservoir. Thermal conductivity, fracture width, and injection temperature have little effect on heat production performance. While increasing the number of production wells can improve the system's uneven flow field distribution, cost and drilling technology considerations make the two-well system the basic form of heat absorption from rocks.
Article
Energy & Fuels
Martijn T. G. Janssen, Deyan Draganov, Auke Barnhoorn, Karl-Heinz A. A. Wolf
Summary: A seismic velocity characterisation study was conducted to investigate the feasibility of re-injection and storage of produced CO2 in a geothermal field. The study examined the effect of stress, pore pressure, pore fluid, and temperature on seismic properties. It was found that the velocity increased with stress, but the increase was more significant at lower stresses. The velocity was also influenced by temperature, with higher temperatures resulting in lower P-wave velocities. The S-wave velocity was more sensitive to changes in pore pressure compared to the P-wave velocity. Nonlinear regression analysis revealed polynomial trends for the velocities as a function of temperature, stress, and pore pressure. However, distinguishing between different fluid saturations in fractures was challenging due to the small fracture aperture.
Article
Chemistry, Multidisciplinary
Martijn T. G. Janssen, Auke Barnhoorn, Deyan Draganov, Karl-Heinz A. A. Wolf, Sevket Durucan
Summary: This study investigated the impact of axial and radial stress on seismic velocity in a geothermal field, highlighting the importance of fractures for permeability. It was found that the closure of microcracks in rocks led to a sharp increase in velocity, while some rocks showed decreasing P-wave velocities with increasing temperature.
APPLIED SCIENCES-BASEL
(2021)
Article
Green & Sustainable Science & Technology
Xuefeng Gao, Yanjun Zhang, Yibin Huang, Yongjie Ma, Yi Zhao, Qiangbin Liu
Summary: Understanding flow and heat transfer in fractured geothermal reservoirs is crucial for the future development of enhanced geothermal systems (EGS). A thermal-hydraulic coupled model was proposed to evaluate heat extraction performance of multilateral wells in fractured reservoirs. Results showed minimal impact of increasing number of branch wells on production temperature but significant impact on well pressure.
Article
Geochemistry & Geophysics
Sanem Elidemir, Nilgun Gulec, Kiymet Deniz, Yusuf Kagan Kadioglu
Summary: The reservoir lithology of the Edremit geothermal field from western Anatolia was investigated using mineralogic-petrographic and geochemical analyses. The study revealed distinct variations in rock composition and chemical characteristics at different depths, suggesting the presence of a potential hydrothermal passageway. This highlights the importance of geochemical studies as significant indicators in geothermal exploration.
APPLIED GEOCHEMISTRY
(2022)
Article
Energy & Fuels
Daffa Arrofi, Israa S. Abu-Mahfouz, Sinatrya Diko Prayudi
Summary: The research investigates the permeable zones and geothermal potential in the non-volcanic geothermal system of north Wawolesea in Indonesia. Lineaments analysis and the fault fracture density (FFD) method are used to understand the fracture geometry, distribution, and density control of permeability in geothermal reservoirs.
Article
Energy & Fuels
Claire Bossennec, Lukas Seib, Matthis Frey, Jeroen van der Vaart, Ingo Sass
Summary: This study quantifies and provides a better understanding of the critical parameters of fracture network pattern in crystalline rocks by investigating eleven outcrops in the Northern Upper Rhine Graben using LiDAR and 2D profiles analysis. The length distribution of fractures shows a multi-scale power-law behavior, driven mainly by fault networks and lithology.
Article
Thermodynamics
Manojkumar Gudala, Suresh Kumar Govindarajan, Bicheng Yan, Shuyu Sun
Summary: This study proposes an improved mathematical model to investigate the temperature variations and mechanical strain in the Puga geothermal reservoir. It is found that there are low-temperature regions within the fractures, and the number of hydraulic fractures and well patterns significantly influence the rock and fluid properties. The proposed mathematical model can effectively evaluate and predict the changes in the reservoir.
Article
Geosciences, Multidisciplinary
Seyed Hossein Hosseini, Banafsheh Habibian Dehkordi, Maysam Abedi, Behrooz Oskooi
Summary: Abgarm in Mahallat, Iran is a well-known geothermal potential area with several hot springs, making it important for geothermal studies. Geophysical surveys were used to image the geometry of geological requisites for trapping a geothermal reservoir, revealing the presence of intrusive igneous rocks and shallow magmatic lava. Additionally, analysis of magnetotelluric (MT) data aided in identifying sedimentary units and magmatic rocks, leading to the illustration of a plausible geothermal reservoir in the area.
NATURAL RESOURCES RESEARCH
(2021)
Article
Geochemistry & Geophysics
Carole Glaas, Jeanne Vidal, Patricia Patrier, Jean-Francois Girard, Daniel Beaufort, Sabine Petit, Albert Genter
Article
Geochemistry & Geophysics
Francis Chopin, Annakaisa Korja, Kaisa Nikkila, Pentti Holtta, Toivo Korja, Mohamed Abdel Zaher, Matti Kurhila, Olav Eklund, O. Tapani Ramo
Article
Energy & Fuels
Pauline Harle, Alexandra R. L. Kushnir, Coralie Aichholzer, Michael J. Heap, Regis Hehn, Vincent Maurer, Patrick Baud, Alexandre Richard, Albert Genter, Philippe Duringer
Article
Geosciences, Multidisciplinary
Carmen Aguilar, Pavla Stipska, Francis Chopin, Karel Schulmann, Pavel Pitra, Prokop Zavada, Pavlina Hasalova, Jean-Emmanuel Martelat
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2020)
Article
Geosciences, Multidisciplinary
Carole Glaas, Jeanne Vidal, Albert Genter
Summary: The study reveals that the permeable fracture zones in the geothermal reservoirs of Soultz-sous-Forets, Rittershoffen, and Illkirch are mainly concentrated in hard rocks, with the highest fracture densities and thicknesses in the first 500-1000 meters of the granite, reflecting the intensity of ancient circulations.
JOURNAL OF STRUCTURAL GEOLOGY
(2021)
Article
Geochemistry & Geophysics
Carole Glaas, Patricia Patrier, Jeanne Vidal, Daniel Beaufort, Albert Genter
Summary: The study focuses on the illitic minerals found in the new Illkirch geothermal well GIL-1 in the French part of the Upper Rhine Graben, comparing them with other geothermal sites and analyzing the mineral assemblages formed under different temperature conditions. Through geochemical analysis and petrographic methods, the characteristics of these permeable areas and the alteration of illitic minerals were determined, providing insights into the distribution and composition of illitic minerals in the region.
Article
Energy & Fuels
Santiago N. Maza, Gilda Collo, Diego Morata, Marco Taussi, Jeanne Vidal, Michele Mattioli, Alberto Renzulli
Summary: Sulphate, clay, silica and oxide-hydroxide minerals were identified in the active and fossil zones of Cerro Apacheta volcano in northern Chile through fieldwork, XRD and SEM analysis. The mineral assemblages in the active zone indicate a Superficial advanced argillic alteration facies associated with an acid-sulphate steam-heated environment, while the fossil zone is interpreted as related to a superficial epithermal environment with different mineral associations. The distribution of hydrothermal alterations is likely controlled by the intersection of NW-SE and NE-SW structures, linked to the Pabelloncito graben.
Article
Geology
Yingde Jiang, Pavla Stipska, Karel Schulmann, Carmen Aguilar, Sheng Wang, Robert Anczkiewicz, Jian Zhang, Pengfei Li, Francis Chopin
Summary: The study of a representative region in the central part of the Chinese Altai reveals a complex relationship between Barrovian- and Buchan-type metamorphic series, indicating different evolutionary processes of metamorphism in the geological history.
JOURNAL OF METAMORPHIC GEOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Mehdi Jouhari, Francis Chopin, Mohamed El Houicha, Jean-Francois Ghienne, Karel Schulmann, Jitka Mikova
Summary: Metasandstones from early Cambrian to early Carboniferous stratigraphic successions in Morocco's Rehamna massif were analyzed. The study revealed different sources for the sediments, indicating important tectonic evolution and reorganization of drainage systems.
JOURNAL OF AFRICAN EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Francis Chopin, Remi Lepretre, Mohamed El Houicha, Anne-Sophie Tabaud, Karel Schulmann, Jitka Mikova, Jocelyn Barbarand, Ryma Chebli
Summary: This paper presents new U-Pb geochronological data on granitoids from the Moroccan Meseta Variscan belt. The results show a peak of magmatic activity at 335.2 +/- 0.8 Ma in the Western Meseta and early Visean magmatic activity in the Eastern Meseta. The study also suggests a possible relationship between the magmatic activity and the tectonic events in Northwest Africa. Evaluation: 8 points.
Article
Geosciences, Multidisciplinary
Clement Baujard, Pauline Rolin, Eleonore Dalmais, Regis Hehn, Albert Genter
Summary: The geothermal powerplant in Soultz-sous-Forets, France, is investigating the possibility of producing more energy by reinjecting the geothermal fluid at lower temperatures. A 3D hydrothermal study was conducted to evaluate the impact of colder reinjection on production temperature, showing a decrease of 2 degrees C after 2 years and 3 degrees C after 25 years. The accuracy of the structural model used for simulations was discussed, with a proposal to update it for better reproduction of observations.
Article
Geosciences, Multidisciplinary
Beatrice A. Ledesert, Ronan L. Hebert, Justine Mouchot, Clio Bosia, Guillaume Ravier, Olivier Seibel, Eleonore Dalmais, Mariannick Ledesert, Ghislain Trullenque, Xavier Sengelen, Albert Genter
Summary: The Soultz-Sous-Forets geothermal site in France operates three deep wells for electricity production, but scales formed from (Ba, Sr) sulfate and (Pb, As, Sb) sulfide types impact energy production and waste management. Analysis of scale samples showed that galena is the main precipitate, with different crystal shapes indicating flow turbulence and growth speed differences. Lowering the temperature led to increased scaling phenomenon, affecting the geothermal system.
Article
Geochemistry & Geophysics
Jerome Azzola, Benoit Valley, Jean Schmittbuhl, Albert Genter