Article
Thermodynamics
Yu Shi, Fuqiang Xu, Xianzhi Song, Gaosheng Wang, Yinhui Zuo, Xiaojiang Li, Jiayan Ji
Summary: This study investigates the evolution of rock damage and its impact on changes in rock physical properties in hot dry rock geothermal systems. Results show that damage increases over time but at a slower rate. Damage reduces Young's modulus and increases permeability, affecting the damage evolution. Factors such as initial temperature, injection flow, and stress difference contribute to greater damage, while fracture curvature has a lesser impact.
Article
Thermodynamics
Gang Liu, Zhengwei Yuan, Chunwei Zhou, Zhijing Fu, Zhenghua Rao, Shengming Liao
Summary: Non-planar fractures are crucial for the efficient operation of enhanced geothermal systems as they greatly impact heat and mass transfer. In this study, the influences of non-planar fractures, continuity, and fracture networks on production temperature, mass flow rate, and power generation rate were comprehensively investigated using thermal-hydraulic-mechanical coupling and finite element methods. Results show that non-planar and continuous fractures reduce flow resistance and fluid leakage, leading to improved heat output.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Musa D. Aliyu, Thomas Finkbeiner, Hua-Peng Chen, Rosalind A. Archer
Summary: This paper presents a numerical model to investigate the influence of thermoelasticity on the thermal performance of enhanced geothermal system (EGS) reservoirs. The results demonstrate that thermoelasticity reduces the energy extraction rate and affects reservoir impedance and thermal front propagation.
Article
Green & Sustainable Science & Technology
Pranay Asai, Robert Podgorney, John McLennan, Milind Deo, Joseph Moore
Summary: This study focuses on optimizing the flow distribution in doublet enhanced geothermal systems (EGS). An analytical model based on Kirchhoff's law is developed to analyze several critical parameters related to well designs. Simulation and sensitivity analysis show that anti-parallel doublet systems perform the best in terms of fluid distribution, and fracture permeability, perforation size, and flow rate also influence the flow distribution.
Article
Energy & Fuels
Yueqiang Ma, Ying Li, Quan Gan, Sheng Zhi
Summary: Thermal energy extraction relies on fluid circulation and heat transfer between fluids and rock matrix. Conductive fracture channel provides effective conduits for fluid circulation and heat energy absorption. The vertical depth variation influences heat reservoir quality and fracture pattern due to stress state and tectonic evolution, which is important for thermal energy production and permeability evolution.
Article
Geosciences, Multidisciplinary
Wenjing Lin, Guiling Wang, Haonan Gan, Shengsheng Zhang, Zhen Zhao, Gaofan Yue, Xiting Long
Summary: This paper analyzes regional variation patterns of mantle heat flow and crustal thermal states, constructs models of temperature fields, and discusses the heat source mechanism of Enhanced Geothermal Systems (EGS) in different zones. The results show that differences in the crustal thermal structure of different regions control their deep thermal conditions and EGS heat sources.
Article
Engineering, Geological
Xin Cui, Louis Ngai Yuen Wong
Summary: Enhanced geothermal systems (EGS) are currently the most efficient method to extract heat from hot dry rock (HDR) reservoirs. This study developed a novel 3D thermo-hydro-mechanical coupling model to predict the long-term performance of EGS. The simulation results showed that while EGS maintains high productivity during early injection stages, it degrades rapidly once thermal drawdown occurs.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Green & Sustainable Science & Technology
Chunwei Zhou, Gang Liu, Shengming Liao
Summary: Successful enhanced geothermal systems depend on fluid flow in fractured reservoir with good fissure connectivity. The study proposes a fuzzy inversion model to explore the location of the predominant flow area. The model achieves good inversion results, reduces dependence on initial guess area and property, and has good anti-interference ability.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Thermodynamics
S. M. S. Mortazavi, O. Rezaie Beydokhti, A. R. Khoei
Summary: The study presents a fully coupled numerical model for Thermo-Hydro-Mechanical simulation of Enhanced Geothermal Systems (EGS) based on the local thermal non-equilibrium using the eXtended Finite Element Method (XFEM) and Equivalent Continuum Method (ECM). The model is validated against analytical solutions and its flexibility and applicability are demonstrated by assessing various parameters' effects on the simulation results.
APPLIED THERMAL ENGINEERING
(2023)
Review
Green & Sustainable Science & Technology
Zhennan Zhu, Shengqi Yang, Pathegama Gamage Ranjith, Wenling Tian, Hong Tian, Jun Zheng, Guosheng Jiang, Bin Dou
Summary: This research analyzed and determined the changes in the mechanical characteristics of granites after various thermal shocks through a comprehensive review of research. The change mechanisms of the mechanical responses of granites after various thermal shocks were revealed by microstructural observations. The macroscale deterioration of the mechanical parameters of various granites after thermal shocks is closely associated with the initiation, development, and coalescence of microcracks.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Geosciences, Multidisciplinary
Saeunn Halldorsdottir, Inga Berre, Eirik Keilegavlen, Gudni Axelsson
Summary: Cooling magma and intrusions are heat sources for hydrothermal systems in volcanic settings. Recent numerical studies have supported the concept of fluid convection in fractures caused by thermal rock contraction. Using numerical simulations, we investigated scenarios for convective downward migration of fractures as a mechanism for the development of hydrothermal systems, and the results support this hypothesis.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Computer Science, Interdisciplinary Applications
Kelvin Bongole, Zhixue Sun, Jun Yao
Summary: The study found that implementing an Enhanced Geothermal System (EGS) beneath the oilfield in the Bongor basin in Chad presents significant advantages in terms of technology, environment, and economy. The use of oilfield produced water and CO2 as heat extraction fluid can improve heat mining efficiency and reduce costs.
SIMULATION MODELLING PRACTICE AND THEORY
(2021)
Article
Green & Sustainable Science & Technology
Matthew L. McLean, D. Nicolas Espinoza
Summary: Viable Enhanced Geothermal Systems require access to large reservoir volumes at high temperatures and sufficient permeability for large production flow rates. However, working fluid injection may decrease recoverable heat energy. This study provides novel numerical simulations of a multi-fracture EGS that considers fracture aperture and its impact on fluid flow and heat recovery. The simulations investigate the reservoir behavior and propose strategies to minimize the severity of thermal short-circuiting.
Article
Engineering, Civil
Luming Zhou, Zhende Zhu, Xinghua Xie
Summary: Hot dry rock (HDR) geothermal energy is an effective alternative to traditional fossil fuels and can be exploited through enhanced geothermal systems (EGS). CO2 may have better performance than water as a working fluid in EGS. The study analyzed the THM coupling mechanism inside the HDR reservoir and validated a dual-medium coupling model. A numerical model was used to compare the heat extraction performance of an EGS using CO2 and water as working fluids.
JOURNAL OF HYDROLOGY
(2023)
Article
Computer Science, Interdisciplinary Applications
S. A. Ghoreishian Amiri, E. Taheri, A. A. Lavasan
Summary: This paper presents a numerical method for modeling coupled thermo-hydro-mechanical processes in porous media saturated with two immiscible fluids. The method combines GFEM, CVFE, and SUCVFE approaches to ensure mass conservation and eliminate oscillations, improving accuracy and efficiency in simulation. The proposed method has been justified through numerical examples and comparison with analytical or numerical solutions.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Geochemistry & Geophysics
Jeremy Riffault, David Dempsey, Satish Karra, Rosalind Archer
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2018)
Article
Environmental Sciences
David Dempsey, Jeremy Riffault
WATER RESOURCES RESEARCH
(2019)
Article
Multidisciplinary Sciences
D. E. Dempsey, S. J. Cronin, S. Mei, A. W. Kempa-Liehr
NATURE COMMUNICATIONS
(2020)
Article
Geochemistry & Geophysics
Alberto Ardid, David Dempsey, Edward Bertrand, Fabian Sepulveda, Pascal Tarits, Flora Solon, Rosalind Archer
Summary: This study introduces a new Bayesian inversion method that integrates MT and borehole MeB data to improve the accuracy of inferring shallow conductor boundaries in geothermal exploration, reducing nonuniqueness and uncertainty.
Article
Geosciences, Multidisciplinary
Alberto Ardid, Rosalind Archer, Edward Bertrand, Fabian Sepulveda, Pascal Tarits, David Dempsey
Summary: This study focuses on quantifying first-order components of a rift-hosted geothermal field by integrating electromagnetic, lithological, and temperature data through 1D models and a stochastic framework. By jointly modeling a multichannel dataset, key heat flows within a complex magmatic-volcanic-hydrothermal province can be accurately quantified. This approach could be beneficial for decision makers in the geothermal industry to optimize sustainable electricity generation and well drilling locations.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Liam J. Kelly, Guilherme A. R. Gualda, Darren M. Gravley, David E. Dempsey
Summary: The study highlights the evidence of crystallization and storage of large magma bodies in the Taupo Volcanic Zone in New Zealand decades to centuries before eruptions. It suggests that convective hydrothermal systems are necessary for short-term heat extraction from large magma bodies, rather than purely conductive models, presenting potential future directions for monitoring unstable calderas in environments with abundant hydrothermal activity like the TVZ.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Engineering, Geological
Pengliang Yu, David Dempsey, Rosalind Archer
Summary: Enhanced Geothermal Systems (EGS) have significant untapped renewable energy potential but face technical and financial challenges before widespread deployment. A new horizontal EGS well design with partially bridging multi-stage hydraulic fractures is proposed to improve heat extraction from hot dry rock (HDR), showing promising results for practical implementation.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Multidisciplinary Sciences
Alberto Ardid, David Dempsey, Corentin Caudron, Shane Cronin
Summary: This study identifies a general seismic precursor signal for gas-driven eruptions through correlation analysis of 18 eruptions in New Zealand, Alaska, and Kamchatka. The precursor is manifested in the displacement seismic amplitude ratio between medium and high frequency tremor bands, exhibiting a characteristic rise in the days prior to eruptions. Real-time monitoring of this precursor may improve short-term eruption warning systems at certain volcanoes.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
David E. Dempsey, Jenny Suckale
Summary: Induced seismicity from gas extraction in the Groningen reservoir in the Netherlands has been occurring since the 1990s. The accuracy and relevance of previous earthquake magnitude forecasts for different extraction scenarios are unknown. This study evaluated a prior forecast and proposed a revised model, which suggested a 1% likelihood of the largest event exceeding M 3.8 (tapered model) or M 5.4 (unbounded model) in the period 2021-2030.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Pengliang Yu, David Dempsey, Antonio Pio Rinaldi, Aimee Calibugan, Vanille A. Ritz, Rosalind Archer
Summary: Data-driven models were used to study the correlation between fluid injection and microseismicity in the geothermal fields of Rotokawa (New Zealand) and Hellisheioi (Iceland). The models helped determine the wells with the strongest correlation and explain this association in a reservoir context. However, no link was found between rapid changes in injection rate and seismicity spikes, as suggested by some theoretical models.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
B. Steinke, A. D. Jolly, R. Carniel, D. E. Dempsey, S. J. Cronin
Summary: This study presents an algorithm based on Self-Organizing Maps (SOM) and k-means clustering to recognize patterns in tremor time series recorded at Whakaari/White Island volcano in New Zealand. The algorithm can be applied to different volcanic settings by adjusting the classifier. Hyperparameters are evaluated statistically to determine the ideal SOM parameters. The study categorizes the seismic time series into regimes representing different volcanic states during recent unrest episodes, and the classification results show a clear separation between background regimes and those representing elevated levels of unrest.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
A. Ardid, D. Dempsey, C. Caudron, S. J. Cronin, C. A. Miller, I. Melchor, D. Syahbana, B. Kennedy
Summary: Volcano crater lakes, while picturesque, may hide small eruptions or hydrothermal fluid release events. This study presents a new method to identify these hidden events using seismic data, and it successfully identifies multiple potential events in different volcanoes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geology
David Dempsey, Jennifer D. Eccles, Jonney Huang, Seokho Jeong, Elia Nicolin, Andrew Stolte, Liam Wotherspoon, Brendon A. Bradley
Summary: The study shows that the upper North Island of New Zealand is vulnerable to earthquakes on the Kerepehi and Wairoa North faults, with potential severe shaking near the source and liquefaction. Cities such as Auckland, Hamilton, and Tauranga could experience moderate to very strong shaking.
NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS
(2021)
Proceedings Paper
Green & Sustainable Science & Technology
Rajesh Pawar, David Dempsey, George Guthrie
13TH INTERNATIONAL CONFERENCE ON GREENHOUSE GAS CONTROL TECHNOLOGIES, GHGT-13
(2017)
Article
Energy & Fuels
Luis Salala, Jonathan Argueta, Noel Lopez, Osmany Aparicio, Diana Martinez, Pedro Santos, Arturo Quezada, Oziel Garcia, Jose Erazo, Hiroyuki Yamagishi, Noriyoshi Tsuchiya
Summary: Geothermal systems have significant potential to replace reliance on fossil fuels. El Salvador, being tectonically active, already supplies a significant portion of its electricity demand using volcanic geothermal fields. The study compares different geothermal areas in El Salvador and highlights the controlling factors in the characteristics of geothermal reservoirs.
Article
Energy & Fuels
Lin Jia, Kewen Li, Yun Han, Chi Zhang, Lipeng Zhao
Summary: This study proposes a new approach of retrofitting abandoned oil wells into geothermal wells, and investigates the effects of different parameters on the performance using a numerical model. The results show that the enhanced fracture system significantly improves the efficiency of geothermal energy extraction, and optimal design should control the flow rate and use proppant.
Article
Energy & Fuels
K. H. Kvalsvik, H. Holmberg, R. K. Ramstad, K. Midttomme
Summary: This study proposes a new analytical equation that takes into account the advective heat in fractured rock, improving the accuracy of measuring thermal properties in borehole heat exchangers. The equation is applicable to all thermal response tests and provides a cost-effective alternative to numerical modelling.
Article
Energy & Fuels
Ronald Dipippo
Summary: This paper presents a technique of further preheating the working fluid in geothermal binary plants using extraction turbines, and evaluates the performance at various geofluid temperatures through working equations. The results indicate that this approach can be equally effective in geothermal binary plants as it is in conventional nuclear power plants.
Article
Energy & Fuels
Y. A. Popov, E. M. Chekhonin, E. G. Savelev, D. A. Ostrizhniy, A. B. Shakirov, R. A. Romushkevich, E. A. Babich, B. E. Andreyev, M. Y. Spasennykh, I. A. Sannikova
Summary: This paper describes the results of experimental geothermal studies on the formation surrounding the Savitskaya-300 well in the Volga-Ural oil and gas basin. The study found high thermal heterogeneity and anisotropy in the formation. The paper provides important data on thermal properties and heat flow variations in the well.
Article
Energy & Fuels
Viren Thakore, Hong Wang, Jy-An Wang, Yarom Polsky, Fei Ren
Summary: This paper focuses on the stability of foam-based fracturing fluid under high temperature and high pressure conditions. It is of significant importance for the development of foam fracturing fluid as an alternative to conventional water-based fracturing fluid in Enhanced Geothermal System (EGS). Experimental results show that with the appropriate selection of surfactants and stabilizing agents, stable foams can be obtained. Analytical models are developed to predict the foam stability for different foam compositions, considering the effects of temperature and pressure.
Article
Energy & Fuels
Hong Chang, Sheng Jiang, Haozhi Jiang, Yunjie Li, Zhengheng Gan, Songying Zhao
Summary: This study compared the bearing performance between phase change energy piles (GPEP) and traditional energy piles (TEP) using indoor modeling tests and theoretical formulas. The results showed that GPEP increased the ultimate bearing capacity of a single pile by about 13% compared to TEP. Additionally, the phase change materials effectively restricted the temperature-drag response of energy piles.
Article
Energy & Fuels
Qiang Zhang, Tiago Alves
Summary: This study investigates the influence of salt structures and faults on the geothermal potential in the Cleaver Bank High, Southern North Sea, using high-quality 3D seismic reflection data and bottom-hole temperature data. The results show that salt structures and faults play a significant role in the geothermal gradient, with higher gradients found on the footwalls of faults. Three potential geothermal exploration targets are identified based on the findings.
Article
Energy & Fuels
Hubert Langevin, Nicolo Giordano, Jasmin Raymond, Louis Gosselin, Martin Bourbonnais
Summary: This study evaluates the efficiency and cost of solar-assisted geothermal systems in a subarctic climate, and offers recommendations for optimizing ground heat exchanger configurations.
Article
Energy & Fuels
Lei Chen, Jinchuan Zhang, Longfei Xu, Shijing Chen, Qianchao Li, Yuhang Sun, Jie Li, Xingxu Zhao
Summary: This study assesses the geothermal water circulation process of a granite geothermal system in the Lancang area, Yunnan using water chemistry and isotope analysis techniques. The results show that the geothermal water originates from atmospheric precipitation and the granite pluton serves as the main heat source. Additionally, the fault system plays an important role in the discharge and mixing of hot and cold water.
Review
Energy & Fuels
Md Azhar, Somenath Mondal, Anh Minh Tang, Akhileshwar K. Singh
Summary: Contemporary geotechnical engineering practice involves the design and construction of structures that encounter thermal cycles. Understanding the effect of temperature on soil mechanical properties is challenging, but there have been significant contributions from numerous studies. However, to date, there is no comprehensive review that provides a holistic development of the subject and its connection to field applications.
Article
Energy & Fuels
Mark White, Yaroslav Vasyliv, Koenraad Beckers, Mario Martinez, Paolo Balestra, Carlo Parisi, Chad Augustine, Gabriela Bran-Anleu, Roland Horne, Laura Pauley, Giorgia Bettin, Theron Marshall, Anastasia Bernat
Summary: The study presents a comprehensive numerical modeling of closed-loop geothermal systems (CLGSs) and develops a publicly accessible web application for feasibility studies. The results suggest that competitive levelized cost of heat (LCOH) can be achieved, but significant reductions in drilling costs are required to achieve competitive levelized cost of electricity (LCOE). A site-based case study for multi-lateral systems and the analysis of permeable wet rock are also provided, indicating the potential for improved power production with higher reservoir permeability and temperature.
Article
Energy & Fuels
Xiaoming Tian, Oleg Volkov, Denis Voskov
Summary: In this study, an efficient and flexible adjoint-based framework is proposed for history matching and forecasting geothermal energy extraction. The framework reduces the parameter space using Principal Component Analysis and speeds up the iteration process using the adjoint method. Operator-based linearization is used for efficient calculation and matrix assembly. The framework is demonstrated to be highly efficient for a heterogeneous reservoir with multiple realizations, generating reliable history-matching results.
Article
Energy & Fuels
Asrillah Asrillah, Agus Abdullah, Klaus Bauer, Ben Norden, Charlotte M. Krawczyk
Summary: At the Gross Scho center dot nebeck geothermal research platform in the NE German Basin, the degree and direction of azimuthal velocity anisotropy caused by sub-vertical fracturing were determined through analysis of 3-D seismic reflection data. The observed anisotropy above the Zechstein salt roughly correlates to fault structures formed by an upwelling salt pillow, while below the salt, the less pronounced anisotropy and interpreted fracturing follow the trend of the regional stress field.
Article
Energy & Fuels
Kyosuke Okamoto, Yusuke Mukuhira, Dian Darisma, Hiroshi Asanuma, Hirokazu Moriya
Summary: Microseismic monitoring is crucial in geothermal development, and manual phase picking for seismic data is time-consuming. Existing deep learning phase pickers may face challenges in geothermal fields due to their unique features. This study focuses on developing a specialized deep learning model for local seismic networks in geothermal fields, allowing automatic hypocenter determinations and revealing subsurface fine structures.
