Article
Materials Science, Multidisciplinary
Ming Tao, Huatao Zhao, Aliakbar Momeni, Wenzhuo Cao, Yan Zhao
Summary: This research evaluated the damage process and dynamic failure behavior of sandstone rocks containing an elliptical hole. Laboratory tests and numerical simulations were conducted to assess the effect of elliptical hole inclination on the strength and dynamic response of the rocks. The results showed that the rock exhibited the lowest strength when the largest diameter of the hole was perpendicular to the core axis under static and dynamic loading conditions.
INTERNATIONAL JOURNAL OF DAMAGE MECHANICS
(2023)
Article
Geochemistry & Geophysics
Zilong Zhou, Zizi Pi, Yue Jing, Shaofeng Wang
Summary: This study investigated the stress, cracking, and failure properties of pre-holed granite under coupled biaxial loading and unloading conditions using numerical simulations and laboratory experiments. The results showed that the inclination angles of the holes significantly affected the peak biaxial unloading strengths, with different trends observed for different types of specimens. Cracks primarily developed along the X-type shear direction, and failure occurred when cracks extended to the size of the pre-hole. Overall failure was triggered when the pre-hole connected with shear slip near the hole.
Review
Green & Sustainable Science & Technology
Xiaojun Feng, Qinjing Hu, Zeng Ding, Dongming Wang, Xue Zhao, Qilei Wei
Summary: Drainage boreholes in soft coal seams are vulnerable to deformation and failure, affecting gas drainage in coal mines. This study explores the crack propagation, acoustic emission, and electromagnetic radiation characteristics of coals with different diameters and strengths during the failure process. The results show that crack propagation occurs significantly after the load peak stage, and the diameter of the holes significantly affects the axial loading limit.
Article
Mechanics
Rui Zhang, Cheng Zhao, Jinquan Xing, Jialun Niu, Huiguan Chen, Yuan Qian
Summary: The presence of inherent microcracks in granite poses challenges to accurately describe crack propagation and fracture behaviors, which are crucial in engineering applications. Our findings suggest that crack propagation is competitively affected by flaw geometry and inherent microcracks. During semi-circular bending, the width of the fracture process zone is influenced by inherent microcracks, while the length is not. The existence of inherent microcracks widens the fracture process zone and increases its influence scope. The fracture process zone and isolated strain concentration caused by inherent microcracks merge to form a continuous fracture path. In addition, the size dependence of fracture toughness was discussed using simulation data.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Geological
Matej Petruzalek, Z. Jechumtalova, T. Lokajicek, P. Kolar, J. Sileny
Summary: Laboratory loading experiments and acoustic emission (AE) monitoring were conducted on different structured granites to observe the fracturing and study the AE source mechanisms. The results showed that rock structure and grain size heterogeneity play crucial roles in controlling the mechanical properties. AE analysis effectively observed the fracturing process and indicated that microcracking was localized in the circumferential portion of the specimens, with sub-vertical cracks dominating the fracturing.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Ecology
Cheng Pan, Guangming Zhao, Xiangrui Meng, Chunliang Dong, Pengfei Gao
Summary: The mesostructure of brittle rocks plays a significant role in their mechanical properties and failure mode. A breakable polygonal discrete element model was developed to simulate the rock mesostructure, and the results revealed a linear relationship between the compressive strength of the rock and mesostructure parameters.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
Article
Engineering, Mechanical
Yan-Hua Huang, Sheng-Qi Yang, Wen-Ling Tian, Shi-Yan Wu
Summary: In this study, uniaxial compression tests were conducted on preholed granite specimens to analyze the mechanical properties, acoustic emission characteristics, and failure patterns of thermally damaged granite. It was found that the peak strength and elastic modulus of the specimens increased and then decreased with the increasing temperature. Cracks always initiated from the perimeters of the pre-existing hole, and the coalescence modes of cracks between the two pre-existing holes were independent of the temperature. Thermal cracks and increased complexity of fracture surface were observed after the treatment at 150 degrees C. The variations in mineral component and crystal structure contributed to the thermal damage of the granite. The experimental results provide insights into the macromechanical and mesomechanical behaviors of rock at high temperatures.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Mechanics
Y. Wang, J. Q. Han, Z. Y. Song, C. Zhu
Summary: The study reveals that communication between the crack network and holes controls the volumetric deformation and final failure modes of the rock. Rock with low flaw angle shows more severe progressive crack unstable propagation. The b value of AE activities exhibits a specific pattern of increase and decrease.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Mechanical
Tao Zhang, Liyuan Yu, Jie Li, Linjian Ma, Haijian Su, Mingwei Zhang, Xingliang Xu, Yuxuan Peng
Summary: This study proposes a novel three-dimensional grain-based model based on the Discrete Element Method (GBM3D-DEM) and successfully reproduces the internal structure of granite. By investigating the effects of micro-strength and micro-elastic modulus of the transgranular contact on the mechanical characteristics and cracking behavior of the sample, as well as the variation of fracture energy, the study confirms the reliability of the proposed model through consistent experimental and numerical results. The study also reveals the significance of micro-strength and micro-elastic modulus of the transgranular contact in determining the mechanical properties and cracking behavior of the sample.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Geological
Xunjian Hu, Haibo Hu, Ni Xie, Yujie Huang, Panpan Guo, Xiaonan Gong
Summary: This study investigates the effect of grain size heterogeneity on the mechanical and microcracking behavior of Lac du Bonnet (LdB) granite. A grain-based model is used, and a grain size heterogeneity index is defined to quantify the heterogeneity. The results show that both grain size heterogeneity and treatment temperature significantly impact the mechanical properties of the granite samples. Empirical formulations are developed to predict the temperature-dependent mechanical properties. The microcracking behavior is also affected by temperature and grain size heterogeneity, including the number, density, orientation, and distribution of cracks.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Nanoscience & Nanotechnology
I Burda, K. Zweiacker, A. Arabi-Hashemi, P. Barriobero-Vila, A. Stutz, R. Koller, H. Roelofs, L. Oberli, M. Lembke, C. Affolter, C. Leinenbach
Summary: Controlling the grain size of steels has a significant impact on their mechanical properties. This study successfully achieved microstructural refinement of a low-alloyed TRIP-assisted bainitic steel through a new industrial thermomechanical treatment. Fatigue tests showed the influence of this treatment on crack propagation behavior. Electron backscatter diffraction, vibrating sample magnetometry, and high-energy synchrotron X-ray diffraction were used to analyze the microstructure near the fatigue crack tip and assess the contribution of martensitic transformation to fracture toughness.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Siyue Fan, Xuming Guo, Qingwei Jiang, Zhenhua Li, Jing Ma
Summary: This article focuses on a new Al-Cu-Mn-Ti-Zr aluminum alloy fabricated by pulsed gas metal arc additive manufacturing to refine the microstructure and alleviate the mechanical property anisotropy. The investigation shows that T6 heat treatment significantly improves the mechanical properties of the alloy samples, but the formation of pores reduces the elongation.
Article
Energy & Fuels
Kareem Ramzy Aboayanah, Afeez K. Popoola, Aly Abdelaziz, Lei Sun, Ekaterina Ossetchkina, Karl Peterson, Giovanni Grasselli
Summary: This paper investigates the impact of pre-existing cracks on thermal cracking processes in granitic rocks using a novel thermo-mechanical grain-based finite discrete element method. The results show that thermal cracks tend to initiate from the tips of pre-existing cracks due to stress concentration, and the number of initiated thermal cracks decreases with increasing pre-existing crack density. Interestingly, increasing the friction coefficient of pre-existing cracks leads to an increase in the number of thermal cracks under different confinement conditions.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Engineering, Mechanical
Yu Wang, Haonan Yang, Jianqiang Han, Chun Zhu
Summary: The study focused on the structural deterioration and fracture evolution behavior of pre-flawed hollow-cylinder granite subjected to multi-stage increasing-amplitude cyclic loads, revealing that rock with high flaw angles exhibit larger volumetric deformation and requires more energy for damage propagation. The research proposed a damage evolution model and analyzed the influence of rock structure on crack network patterns.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Engineering, Geological
Pingye Guo, Mohua Bu, Peng Zhang, Jiamin Wang, Zhaolong Luan, Manchao He
Summary: This study experimentally investigated the mechanical properties and thermal damage mechanism of granite subjected to high temperature. A novel discrete element numerical model incorporating the real mineral distribution was introduced and validated by experiments. The mechanical behavior, crack propagation behavior, and failure mode of granite after high temperature were studied. The results showed that 450 degrees C was the thermal damage threshold for granite. Below this temperature, the development of thermally-induced microcracks was not significant, while above this temperature, rapid microcrack propagation and deterioration of mechanical properties were observed. The simulation results revealed that the number of thermally-induced microcracks in granite specimens was positively correlated with temperature, and the thermal stress concentration between mineral particles was the main cause of these microcracks. The uniaxial compression failure mode of granite specimens also changed with temperature, with a brittle-plastic transition observed between 600 degrees C and 750 degrees C.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
Sheng-Qi Yang, Miao Chen, Yan Tao
Summary: The anchorage method and pretightening force significantly affect the peak strength and elastic modulus of non-persistent jointed rock mass. Different anchorage methods result in varying mechanical properties, while an increase in pretightening force also has a significant impact on strength and deformation characteristics.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Engineering, Geological
Zhen Yang, Sheng-Qi Yang, Wen-Ling Tian
Summary: This study developed a fully coupled thermo-mechanical model within the framework of ordinary state-based peridynamics to investigate the thermal-mechanical properties and fracture characteristics of granite materials under real-time temperature (RT) and post-temperature (PT) treatments. A modified multi-layer computational method was proposed to eliminate the effect of thermal gradient-induced cracks. The stress-strain and cracking behaviors of both RT and PT samples could be properly simulated using the proposed method.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Energy & Fuels
Wen-Ling Tian, Sheng-Qi Yang, Jian-Guo Wang, Jin-Peng Dong
Summary: The study revealed that conducting triaxial compression tests on thermally treated granite at different temperatures can analyze its mechanical properties, with higher temperatures leading to more severe damage and reduction in peak strength.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2021)
Article
Energy & Fuels
Jing Yang, Sheng-Qi Yang, Guang-Jian Liu, Wen-ling Tian, Ye Li
Summary: The study found that the development of micro-cracks in rock samples shows a trend of high-energy fracture points, low-energy and small fracture regions, extensive fracture regions, and macroscopic fracture zones. The difference in rock failure mode arises from the influence of rock bridges on the high-energy fractures, leading to differences in the formation of main damage zones in rock samples. The variation of the rock bridge inclination angle gradually affects the total number of micro-cracks, proportion of shear cracks, and mixed-mode cracks, causing rock samples to evolve from simple tensile failure mode to complex crack penetration mode.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2021)
Article
Engineering, Environmental
Zhennan Zhu, Shengqi Yang, Pathegama Gamage Ranjith, Hong Tian, Guosheng Jiang, Bin Dou
Summary: Understanding the deformation and failure characteristics of rocks under thermal treatment is crucial in deep rock engineering. A statistical model for rock deformation was established, considering the temperature effect, and the model showed good agreement with experimental data. The improved model captured the void compaction stage of granite after high temperature better than the classic damage model.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Engineering, Geological
Sheng-Qi Yang, Jin-Zhou Tang, Su-Sheng Wang, Dian-Sen Yang, Wen-Tang Zheng
Summary: The objective of this work is to investigate the creep damage mechanism of granite from a nuclear power station. A series of multi-step loading and unloading cycles creep tests of granite were carried out under different confining pressures. The results show that the short-term strength, crack damage threshold, and Young's modulus all increased with the increasing of confining pressure. An exponential function is proposed, which can well describe the relationship between the visco-plastic strain and stress ratio. The damage mechanism of the failed granite specimens is analyzed using an X-ray micro-CT scanning system. A time-dependent damage model is proposed to quantitatively characterize the creep damage and deformation behaviors of granite.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Mechanical
Bo-Wen Sun, Sheng-Qi Yang, Jie Xu, Peng-Fei Yin
Summary: Based on the discrete element method, this study established a numerical model to investigate the macro- and meso-mechanical properties of bedded shale under different unloading paths and bedding inclinations. The results revealed that bedding inclination has a significant influence on mechanical parameters and failure modes under unloading. The peak strength and ultimate bearing capacity showed a U-shaped trend, with maximum values observed at beta = 0 degrees or beta = 90 degrees and minimum values at beta = 30 degrees or beta = 45 degrees. The failure modes varied depending on the bedding inclination, with splitting damage observed at lower initial confining pressure for beta = 0 degrees and shear-slip damage observed for beta = 15-45 degrees. Shale specimens with beta = 60-90 degrees exhibited conjugate shear damage intersecting with the weak surface. The damage caused by unloading and increasing axial stress was greater than that caused by unloading and constant axial strain. The effects of beta = 0 degrees and 90 degrees on microcracking and stress distribution within the specimen were significantly smaller compared to other bedding inclinations.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Sheng-Qi Yang, Ye Li, Guo-Wei Ma, Bo-Wen Sun, Jing Yang, Jie Xu, Yong-Hao Dai
Summary: The dynamic compression experiments were conducted on granite specimens after high-temperature treatments, and the fragmentation characteristics were evaluated using fractal dimension and average fragment size. The results showed that the physical properties of the granite were closely related to the temperature, and microcracking occurred at 900 degrees Celsius. The fractal dimension and average fragmentation size were found to be inversely linearly related, and the crack propagation during dynamic compression followed a pattern of initial appearance on the surface and gradual propagation to the interior.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Geological
Zhen Yang, Sheng-Qi Yang, Wenbo Zheng, Dwayne D. Tannant
Summary: This paper presents an improved multi-layer computational method based on fully coupled thermal-mechanical OSB-PD for simulating fracturing in granite under coupled thermal-hydraulic effects. The method includes four computational layers and was verified through simulation and comparison with experimental results. It successfully predicts the behavior of granite specimens subjected to HTHP hydraulic fracturing tests.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Green & Sustainable Science & Technology
Jinzhou Tang, Shengqi Yang, Ke Yang, Wenling Tian, Guangjian Liu, Minke Duan
Summary: A new thermal damage numerical model was proposed to analyze the cracks on pre-cracked red sandstone after thermal treatment. The thermal damage value, obtained by extracting the thermal crack area from SEM images, served as an indicator of the degree of thermal damage. By replacing the flat-joint model with the smooth-joint model based on the thermal damage value, the mechanical behavior and failure patterns of sandstone were accurately simulated. In addition, the critical temperature for strength reduction was found to be 750 degrees C.
Article
Energy & Fuels
Sheng-Qi Yang, Shuai-Bo Xu, Zhen Liu, Bo-Wen Sun, Peng-Fei Yin
Summary: In this study, stress-strain curves of sandstone soaked in 5% NaCl and 5% K2SO4 solutions were obtained under different loading and unloading paths. The results showed that sandstone soaked in 5% NaCl exhibited greater unloading capacity compared to sandstone soaked in 5% K2SO4. The strain change rate during the unloading process was higher for sandstone soaked in 5% K2SO4. The deformation modulus and Poisson's ratio of sandstone soaked in 5% NaCl were greater and less than those of sandstone soaked in 5% K2SO4, respectively. The total energy absorbed by sandstone soaked in 5% NaCl was always lower than that soaked in 5% K2SO4.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2023)
Article
Energy & Fuels
Pengfei Yin, Shengqi Yang, Feng Gao, Wenling Tian
Summary: Drilling wellbores in shale reservoirs can lead to instability due to the stress release and change in stress equilibrium. This study investigated the strength, failure, strain energy evolution, and micro-crack damage of shale specimens under confining pressure unloading conditions. The research revealed that confining pressure unloading induces greater plastic deformation, more micro-crack damage, and a more complex failure pattern.
Editorial Material
Energy & Fuels
Chun Zhu, Shengqi Yang, Yuanyuan Pu, Lijun Sun, Min Wang, Kun Du
Article
Engineering, Geological
Yu Song, Sheng-Qi Yang, Ke-Sheng Li, Peng-Fei Yin, Peng-Zhi Pan
Summary: This study establishes a three-dimensional numerical model to investigate the failure behavior of transversely isotropic rock formations, with a focus on the effects of confining pressure and laminar inclination angle. The results of the numerical simulations show that the confining pressure and laminar angle significantly influence the internal crack evolution patterns of the specimen.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Metallurgy & Metallurgical Engineering
Sheng-qi Yang, Jin-peng Dong, Jing Yang, Zhen Yang, Yan-hua Huang
Summary: Fissures play a significant role in predicting the unstable failure of rock mass engineering. In this research, the effect of bridge angle and confining pressure on the mechanical behavior of granite specimens containing pre-existing fissures was evaluated. The study found that confining pressure affects the strength, deformation characteristics, and crack evolution behavior of the granite specimens.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2022)
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.
