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Research And Practice Of Four-Dimensional In-Situ Stress Fields For Deep Coalbed Methane Production: A Case Study Of The Daning-Jixian Block, Ordos Basin, Wang Chengwang, Chen Yiyu, Gao Deli, Zhao Haifeng, Chen Gaojie Jul 2026

Research And Practice Of Four-Dimensional In-Situ Stress Fields For Deep Coalbed Methane Production: A Case Study Of The Daning-Jixian Block, Ordos Basin, Wang Chengwang, Chen Yiyu, Gao Deli, Zhao Haifeng, Chen Gaojie

Coal Geology & Exploration

Background Deep coalbed methane (CBM) reservoirs are characterized by well-developed microstructures and natural fractures, along with highly heterogeneous rock mechanical properties and in-situ stress field distribution. The CBM production of the reservoirs tends to cause constantly evolving formation pressure and in-situ stress within the control ranges of CBM wells, further enhancing the complexity of stress distribution. Additionally, severe fracturing channeling can be observed between new and old wells. This phenomenon is primarily triggered by in-situ stress variations induced by large-scale fracturing and CBM production. Therefore, accurately assessing the dynamic evolutionary patterns of in-situ stresses in reservoirs after fracturing and during …


Numerical Simulations And Dispersion Analysis Of 3d In-Seam Waves Based On Finite Difference Method On Curvilinear Grids, Liu Dan, Ren Zhiming Jul 2026

Numerical Simulations And Dispersion Analysis Of 3d In-Seam Waves Based On Finite Difference Method On Curvilinear Grids, Liu Dan, Ren Zhiming

Coal Geology & Exploration

Background With the comprehensive advancement in intelligent coal mine construction, creating high-precision, transparent geological models of coal seams and their surrounding strata has emerged as a prerequisite for intelligent coal mining. The accurate identification of concealed geological anomalies, such as folds and faults, within coal seams represents a key challenge in safe coal mining. In-seam seismic exploration has become an important approach to detecting underground concealed structures owing to its advantages, including a considerable detection distance along coal seams, high precision, pronounced frequency dispersion effects, and facilitating the identification of waveform signatures. However, conventional methods for seam wave simulation are …


Hydrodynamic Evolution Simulations And Safety Assessment Of The Deep Reinjection And Storage Of High-Salinity Mine Water, Xu Zhimin, Chen Weixiao, Sun Yajun, Zhang Jian, Chen Tianci, Liu Qi, Chen Ge, Hua Jingfan Jun 2026

Hydrodynamic Evolution Simulations And Safety Assessment Of The Deep Reinjection And Storage Of High-Salinity Mine Water, Xu Zhimin, Chen Weixiao, Sun Yajun, Zhang Jian, Chen Tianci, Liu Qi, Chen Ge, Hua Jingfan

Coal Geology & Exploration

Objective In some mining areas of North China-type coalfields, large volumes of high-salinity mine water produced during coal mining pose dual challenges: high treatment costs to meet discharge standards and the waste of mine water resources due to inefficient utilization before discharge. In recent years, the deep reinjection and storage technology for high-salinity mine water has provided a new approach to this issue. To achieve this technology, it is essential to understand the flow field evolution during mine water reinjection and address reinjection-induced safety problems. Methods This study investigated coal mine A in Jiangsu Province as an example. Using the …


Factors Influencing Productivity And Production System Optimization For Deep Coalbed Methane In The Daning-Jixian Block, Ordos Basin, Zhao Haifeng, Jia Zhaojie, Chen Mengqi, Yang Ziyi, Wang Bin, Lin Hongliang, Yang Yanfeng Feb 2026

Factors Influencing Productivity And Production System Optimization For Deep Coalbed Methane In The Daning-Jixian Block, Ordos Basin, Zhao Haifeng, Jia Zhaojie, Chen Mengqi, Yang Ziyi, Wang Bin, Lin Hongliang, Yang Yanfeng

Coal Geology & Exploration

Objective Deep coalbed methane (CBM) reservoirs are characterized by ultra-low porosity, ultra-low permeability, and super saturation, rendering it impractical to copy the productivity models of shallow coalbed methane and shale gas. Furthermore, the production performance of deep CBM varies significantly across different well sections. However, the impacts of different factors on the productivity of deep CBM remain poorly understood. This study conducted a numerical simulation analysis of the productivity of deep CBM in the Daning-Jixian block along the eastern margin of the Ordos Basin based on the geological characteristics of the block, aiming to explore the impacts of various key …


Numerical Simulation Of Co2 Sequestration Combined With Enhanced Geothermal Energy Extraction In Deep Saline Aquifers, Xie Zehao, Zhang Liehui, Zhao Yulong, Cao Cheng, Kou Zuhao, Zhang Deping, Li Jinlong Jan 2026

Numerical Simulation Of Co2 Sequestration Combined With Enhanced Geothermal Energy Extraction In Deep Saline Aquifers, Xie Zehao, Zhang Liehui, Zhao Yulong, Cao Cheng, Kou Zuhao, Zhang Deping, Li Jinlong

Coal Geology & Exploration

Objectives and Methods Deep saline aquifers represent ideal spaces for geologic CO2 sequestration while also featuring high geothermal gradients and abundant geothermal resources. The combination of CO2 sequestration and geothermal energy extraction holds great significance for enhancing the CO2 sequestration effect and achieving integrated resource development of deep saline aquifers. Therefore, this study proposed a development approach that combined CO2 sequestration with geothermal energy extraction in deep saline aquifers and established a thermo-hydro-chemical coupling numerical simulation model of the gas-water two-phase flow. Accordingly, it explored the optimal injection mode, production and injection well patterns, and injection …


Multi-Field Coupling-Based Numerical Simulations Of Co2 Storage In Saline Aquifers: A Case Study Of The Dingji Coal Mine, Huainan Mining Area, Li Dianshang, Zheng Sijian, Liao Qingfa, Miao Wei, Tian Yuchen, Zhang Helong, Liu Yanzhi, Liu Shiqi Dec 2025

Multi-Field Coupling-Based Numerical Simulations Of Co2 Storage In Saline Aquifers: A Case Study Of The Dingji Coal Mine, Huainan Mining Area, Li Dianshang, Zheng Sijian, Liao Qingfa, Miao Wei, Tian Yuchen, Zhang Helong, Liu Yanzhi, Liu Shiqi

Coal Geology & Exploration

Background Saline aquifers are characterized by extensive distribution, abundant reserves, and substantial potential for CO2 storage, establishing them as the most promising geological media for carbon capture, utilization, and storage (CCUS). CO2 storage in saline aquifers plays a crucial role in mitigating the greenhouse effect and achieving the goals of peak carbon dioxide emissions and carbon neutrality. Thoroughly investigating CO2 storage in deep saline aquifers within the Huainan mining area helps alleviate the regional pressure of carbon emission reduction while also providing important support for expanding the technical pathways of CCUS and promoting its engineering applications. Methods …


A Simulation Study On A Dual-Borehole Dc Resistivity System For Advance Detection Under Varying Angles, Zhou Guanqun, Xu Shaotian, Zhang Weixin, Wang Yafei, Wu Xiaoping, Hu Xiongwu, Chen Xinghai, Cao Yu Dec 2025

A Simulation Study On A Dual-Borehole Dc Resistivity System For Advance Detection Under Varying Angles, Zhou Guanqun, Xu Shaotian, Zhang Weixin, Wang Yafei, Wu Xiaoping, Hu Xiongwu, Chen Xinghai, Cao Yu

Coal Geology & Exploration

Significance Mine direct current (DC) methods, an efficient geophysical exploration technique, can be used to identify and delineate underground electrical resistivity anomalies, serving as a critical means for the advance detection of water-bearing or hydraulically conductive structures ahead of the mining face. Methods By combining the water exploration and discharge boreholes commonly used in coal mining and making reference to the observation system of the ground-based cross-borehole DC resistivity CT method, this study devised a dual-borehole DC resistivity observation system for advance detection. Through numerical simulation using the COMSOL software, this study constructed a homogeneous full-space model, in which a …


Numerical Simulations Of The Overburden Stability In Underfilling Zones During Continuous Mining And Continuous Backfilling Of Coal Mines, Liu Lang, Luo Yixiao, Zhu Mengbo, He Jun, Qu Huisheng, Duan Huaijun, Wei Baoning, Liu Zhizhen Oct 2025

Numerical Simulations Of The Overburden Stability In Underfilling Zones During Continuous Mining And Continuous Backfilling Of Coal Mines, Liu Lang, Luo Yixiao, Zhu Mengbo, He Jun, Qu Huisheng, Duan Huaijun, Wei Baoning, Liu Zhizhen

Coal Geology & Exploration

Objective and Method Coals serve as a predominant energy source in China. However, coal mining has resulted in increasingly pronounced ecological issues such as ground subsidence and solid waste accumulation. Although the continuous mining and continuous backfilling (CMCB) technology allows for efficient resource recovery and ecological protection through backfilling with coal-based solid waste, the issue of insufficient roof-contact backfilling (termed underfilling) poses a serious threat to the overburden stability during mining. Given the unclear mechanisms behind the influence of coupled multiple factors of underfilling zones in current research, this study constructed three-dimensional numerical models using the 3DEC discrete element software …


Numerical Simulations Of The Influence Of Vegetation Configuration On Dust Migration In Open-Pit Coal Mines, Han Li, Li Renjie, Bi Yinli Oct 2025

Numerical Simulations Of The Influence Of Vegetation Configuration On Dust Migration In Open-Pit Coal Mines, Han Li, Li Renjie, Bi Yinli

Coal Geology & Exploration

Background Dust pollution emerges as a major environmental challenge in the open-pit mining of coal mines. Ecological restoration has found widespread applications in mining areas as a crucial measure. However, there is a lack of systematic studies on the role of vegetation configuration in dust migration. Methods Using the computational fluid dynamics (CFD) method for numerical simulation, this study constructed a comprehensive simulation framework incorporating wind field reconstruction, dust migration, and the dust retention capacity of vegetation. By setting different particle sizes and wind speeds, this study systematically analyzed dust migration patterns. Furthermore, vegetation configuration was introduced into the simulation …


Injection-Production Process Parameters Of Well Group Configurations For Autothermic Pyrolysis In Situ Conversion Of Oil Shale, Zeng Yijian, Zhu Chaofan, Li Yanwei, Shui Haoche, Guo Wei Sep 2025

Injection-Production Process Parameters Of Well Group Configurations For Autothermic Pyrolysis In Situ Conversion Of Oil Shale, Zeng Yijian, Zhu Chaofan, Li Yanwei, Shui Haoche, Guo Wei

Coal Geology & Exploration

Background A well group acts as a multi-well synergistic unit, and its configuration directly determines both the selection of optimal injection–production process and the utilization efficiency of stratigraphic conditions, ultimately affecting the overall performance of resource recovery. Methods Using numerical simulations, this study assessed the performance of autothermic pyrolysis in situ conversion (ATS) under three vertical well group configurations: one injection well and one production well (1I1P), one injection well surrounded by four production wells (1I4P), and one injection well surrounded by six production wells (1I6P). Furthermore, it revealed the synergistic mechanisms between well group configuration and energy efficiency. Results …


Well Spacing Optimization Technology For Coalbed Methane Horizontal Wells, Wang Yuting, Yang Yanhui, Zhang Cong, Wang Xiuwei, Liu Zhong, Chen Jiale, Dong Qing, Sun Tao, Zhang Wuchang, Li Kexin, Wang Qi Aug 2025

Well Spacing Optimization Technology For Coalbed Methane Horizontal Wells, Wang Yuting, Yang Yanhui, Zhang Cong, Wang Xiuwei, Liu Zhong, Chen Jiale, Dong Qing, Sun Tao, Zhang Wuchang, Li Kexin, Wang Qi

Coal Geology & Exploration

Background Well spacing design directly affects the resource utilization and exploitation benefits of blocks. Rational well spacing design plays a significant role in the commercial exploitation of coalbed methane (CBM) fields. Since the beginning of China’s 14th Five-Year Plan, blocks for CBM production in the southern Qinshui Basin have experienced a gradual increase in burial depth, a progressive decline in permeability, and a constant update of primary exploitation technology. Consequently, traditional well spacings fail to meet the requirements for field CBM exploitation any longer. Methods This study investigated the western Qinnan – eastern Mabi block by combining numerical simulations with …


Deterioration And Instability Mechanisms Of Water-Rich And Weakly Cemented Open-Pit Slopes, Wang Ming, Wu Zhang, Xu Changyou, Zhao Fu, Meng Xiangchun, Shi Bin, Liu Jingyu, Xu Yongchao, Wang Jingwei, Zhao Lichun Aug 2025

Deterioration And Instability Mechanisms Of Water-Rich And Weakly Cemented Open-Pit Slopes, Wang Ming, Wu Zhang, Xu Changyou, Zhao Fu, Meng Xiangchun, Shi Bin, Liu Jingyu, Xu Yongchao, Wang Jingwei, Zhao Lichun

Coal Geology & Exploration

Background During the mining of an open-pit mine, denudated layers contain loose Neogene and Quaternary aeolian, alluvial, and diluvial deposits, facilitating water storage and conduction. This is prone to cause slope degradation and instability, severely threatening mining safety. Methods Based on results from field surveys and laboratory experiments, this study systematically analyzed the impacts of groundwater on the weak layer along a slope of an open-pit mine in the Huolinhe Coalfield, Inner Mongolia, focusing on its softening effect on mudstones. By establishing a mechanical model for unconsolidated strata, this study derived an equation for calculating the seepage force in the …


Groundwater Rebound And Seepage Characteristics And Water Quality Evolution In A Sealed Mining Area In North China Type Coalfield, Yin Huiyong, Sun Dehui, Dong Fangying, Wang Fanhua, Zhang Lifeng, Wu Tao, Liu Chao, Zeng Yifan Jul 2025

Groundwater Rebound And Seepage Characteristics And Water Quality Evolution In A Sealed Mining Area In North China Type Coalfield, Yin Huiyong, Sun Dehui, Dong Fangying, Wang Fanhua, Zhang Lifeng, Wu Tao, Liu Chao, Zeng Yifan

Coal Geology & Exploration

Background The seepage field and water quality evolution associated with the groundwater rebound induced by the sealing of mining areas significantly affects the prevention and control of mine water hazards, as well as the recycling of water resources. Systematically elucidating the mechanisms underlying the seepage-hydrochemistry synergy of groundwater is recognized as a fundamental scientific issue for promoting the collaborative management and resource development of the water systems in mining areas. Methods Based on the engineering background of the sealed No.116 mining area in the Binhu Coal Mine, Zaozhuang, Shandong Province, this study investigated the groundwater rebound and seepage characteristics, along …


Impacts Of Boundary Conditions And Parameter Heterogeneity On The Simulation And Prediction Of Water Inflow In Coal Mines, Ji Qiang, Wu Zhenjiang, Yao Yingying Jul 2025

Impacts Of Boundary Conditions And Parameter Heterogeneity On The Simulation And Prediction Of Water Inflow In Coal Mines, Ji Qiang, Wu Zhenjiang, Yao Yingying

Coal Geology & Exploration

Background Accurate prediction of water inflow in coal mines is essential for ensuring safe mining operations. Three-dimensional (3D) groundwater numerical models can be used to characterize hydrogeological conditions in mining areas and simulate the dynamic processes of water inflow, providing a theoretical basis for scientifically predicting mining-induced water inflow. However, there is a lack of a clear understanding of the impacts of the boundary conditions with surface water-groundwater interactions and the heterogeneity of aquifer permeability coefficients (K) on the simulation and prediction of water inflow during coal mining. Methods This study developed a 3D transient groundwater numerical model …


An Experimental Study On The Seepage Characteristics Of Sandstones With Different Numbers Of Fractures Before And After Grouting, Chen Juntao, Zhou Haoyu, Yu Junjian, Li Guo, Fan Mingjin, Li Lu, Wang Yunhao Jul 2025

An Experimental Study On The Seepage Characteristics Of Sandstones With Different Numbers Of Fractures Before And After Grouting, Chen Juntao, Zhou Haoyu, Yu Junjian, Li Guo, Fan Mingjin, Li Lu, Wang Yunhao

Coal Geology & Exploration

Background Grouting in surrounding rocks serves as a conventional approach to controlling disasters in coal mine roadways. The developmental degree of fractures significantly influences the reinforcement and sealing effects of grouting. Methods To determine the changes in the impermeability of fractured surrounding rocks before and after grouting, this study investigated sandstones—the most common sedimentary rocks in coal mines. Using laboratory experiments and numerical simulations, this study explored the permeability variations of sandstone specimens with varying fracture numbers under different confining pressures and assessed the impact of grouting on their seepage performance. Through triaxial compression-seepage experiments using a Rock Top multi-field …


Parameter Optimization For Multistage Horizontal Well Fracturing Based On Multi-Cluster Perforation For Deep Coal Measure Gas: A Case Study Of The Jurassic Baijiahai Area In The Junggar Basin, Wang Bo, Jin Chenghong, Liu Jiang, Wang Zhiwei, Li Shenjian, Sheng Mao Apr 2025

Parameter Optimization For Multistage Horizontal Well Fracturing Based On Multi-Cluster Perforation For Deep Coal Measure Gas: A Case Study Of The Jurassic Baijiahai Area In The Junggar Basin, Wang Bo, Jin Chenghong, Liu Jiang, Wang Zhiwei, Li Shenjian, Sheng Mao

Coal Geology & Exploration

Objective The multistage horizontal well fracturing based on multi-cluster perforation has emerged as an effective approach for the efficient production of deep coal-measure gas (CMG). However, deep coals feature unique rock mechanical properties, fluid loss characteristics of reservoirs, and microfracture developmental characteristics, which differ significantly from those of unconventional shales, tight sandstones, and shallow coals. As a result, existing fracturing experience cannot be directly applied, highlighting the investigation of fracturing parameter optimization tailored for deep CMG production.Methods Focusing on deep CMG reservoirs in the Baijiahai area within the Junggar Basin, this study constructed a model of multistage horizontal well …


Multi-Field Information Fusion-Based Analysis Of The Macroscopic And Mesoscopic Damage Evolution And Location Identification Of Caving And Water-Conducting Fracture Zones For Mining Overburden, Wei Jiangbo, Wang Shuangming, Liu Lang, Wei Baoning, Chong Deyu, Liu Zhizhen, Li Dongkui, Zhuang Dengdeng, Zhou Jing Apr 2025

Multi-Field Information Fusion-Based Analysis Of The Macroscopic And Mesoscopic Damage Evolution And Location Identification Of Caving And Water-Conducting Fracture Zones For Mining Overburden, Wei Jiangbo, Wang Shuangming, Liu Lang, Wei Baoning, Chong Deyu, Liu Zhizhen, Li Dongkui, Zhuang Dengdeng, Zhou Jing

Coal Geology & Exploration

Objective For the coal mining areas in the middle reaches of the Yellow River, there is an urgent need to determine the failure characteristics of the mining overburden and the spatial structural evolution of caving and water-conducting fracture zones in the overburden, which is recognized as the major challenge in coal mining through gangue grouting filling in goaves. Methods To accurately identify the locations of the caving and water-conducting fracture zones in the mining overburden, this study investigated mining face 42205 in the Liangshuijing Coal Mine in northern Shaanxi Province. Using drilling data, this study constructed a numerical model of …


Anisotropy In Non-Darcy Flow In Individual Rough-Walled Rock Fractures, Zhu Yinbin, Liao Zhen, Li Changdong, Liu Hongbin, Jiang Xihui Feb 2025

Anisotropy In Non-Darcy Flow In Individual Rough-Walled Rock Fractures, Zhu Yinbin, Liao Zhen, Li Changdong, Liu Hongbin, Jiang Xihui

Coal Geology & Exploration

Objective Investigating the flow behavior of fluids in individual rough-walled rock fractures is fundamental for fully understanding the seepage characteristics of fluids in rock fracture networks. Methods Rock fractures were artificially synthesized based on the fractal theory, and numerical simulations of seepage along these fractures were performed using the COMSOL Multiphysics software. Then, fracture specimens with the same geometric characteristics as numerical models of fractures were prepared using 3D printing technology. In combination with the self-designed equipment for seepage experiments, this study conducted seepage experiments on these fracture specimens under different injection flow rates to investigate the impacts of varying …


Developmental Patterns And Formation And Evolutionary Mechanisms Of Surface Cracks Induced By The Mining Of Shallowly Buried Coal Seams, Hou Enke, Mu Jiaxin, Xie Xiaoshen, Feng Dong, Yang Lei, Li Yan, He Tao, Bao Kangguang, Chen Xiaosheng Feb 2025

Developmental Patterns And Formation And Evolutionary Mechanisms Of Surface Cracks Induced By The Mining Of Shallowly Buried Coal Seams, Hou Enke, Mu Jiaxin, Xie Xiaoshen, Feng Dong, Yang Lei, Li Yan, He Tao, Bao Kangguang, Chen Xiaosheng

Coal Geology & Exploration

Objective Surface cracks are recognized as one of the most common geologic hazards in coal mining areas in northern Shaanxi Province. These cracks directly cause damage to surface ecosystems. Furthermore, those penetrating fractures in the overburden act as primary channels for surface water to burst underground, threatening the safe production underground. Methods This study aims to further reveal the developmental patterns of surface cracks induced by the mining of shallowly buried coal seams and elucidate their formation and evolutionary mechanisms. To this end, this study investigated mining face 15218 and 25213 in the Hongliulin Coal Mine in northern Shaanxi. Specifically, …


Commingling Production Of Deep Coal-Measure Gas Through Hydraulic Fracturing: Propagation Patterns Of Induced Fractures And Their Determinants, Chen Hao, Li Guozhang, Qin Yong, Wang Jianguo, Shen Jian, Sun Yuqi, Yuan Erjun, Li Dian Dec 2024

Commingling Production Of Deep Coal-Measure Gas Through Hydraulic Fracturing: Propagation Patterns Of Induced Fractures And Their Determinants, Chen Hao, Li Guozhang, Qin Yong, Wang Jianguo, Shen Jian, Sun Yuqi, Yuan Erjun, Li Dian

Coal Geology & Exploration

Objective The commingling production of coal-measure gas represents a pivotal approach to enhancing the single-well production of unconventional gas in China. However, coal-measure gas reservoirs exhibit distinctly different material compositions and physical properties, leading to uncertainty of the propagation modes and developmental degrees of fractures in different reservoirs during the hydraulic fracturing of coal-measure gas reservoirs subjected to commingling production. Therefore, effectively coordinating the stimulation of multiple reservoirs for multi-gas commingling production is crucial for minimizing production costs and maximizing production capacity. Methods This study investigated the Linxing block along the northeastern margin of the Ordos Basin as an example …


Failure Depths Of Stope Floors Under Dynamic Loading Induced By Roof Breaking, Huang Qisong, Xu Bo, Feng Junjun, Lin Xiaofei, Cheng Jiulong, Peng Jun Dec 2024

Failure Depths Of Stope Floors Under Dynamic Loading Induced By Roof Breaking, Huang Qisong, Xu Bo, Feng Junjun, Lin Xiaofei, Cheng Jiulong, Peng Jun

Coal Geology & Exploration

Objective Accurately assessing the failure depths of stope floors is crucial for assessing floor water inrush risks. Conventional theoretical models for calculating the failure depths generally merely consider static loads from the support pressure and confined water's pressure in stopes, leading to large deviations between calculation results and actual situations. Therefore, constructing a more practical computational model that comprehensively considers the coupled effects of multiple force sources on the failure of deep floors can provide a scientific basis for the effective prevention and control of water hazards in deep coal seam floors. Methods Based on the dynamic elasticity theory and …


Spatiotemporal Response Characteristics Of Transient Electromagnetic Field In Water-Bearing Goaves And Their Applications, Song Guilei, Gong Xufei, Yang Fuqiang, Cui Jianting, Li Zhanling, Liu Lina Dec 2024

Spatiotemporal Response Characteristics Of Transient Electromagnetic Field In Water-Bearing Goaves And Their Applications, Song Guilei, Gong Xufei, Yang Fuqiang, Cui Jianting, Li Zhanling, Liu Lina

Coal Geology & Exploration

Objective and Methods This study aims to enhance the accuracy of the mine transient electromagnetic method (MTEM) in of imaging of water-bearing goaves. Based on the geological conditions of the Gaojialiang Coal Mine, this study simulated the spatiotemporal response characteristics of the induced magnetic field in the water-bearing goaf model under varying stratigraphic spacings using finite element software COMSOL. Accordingly, this study analyzed the distribution patterns of the induced magnetic field on the apparent resistivity pseudosections and the plots of the differentials of longitudinal apparent conductivity. Using the results, the water-bearing conditions of goaves in the Ordos Gaojialiang Coal Mine …


Transient Electromagnetic Numerical Simulation Based On The Transformer Neural Network, Wang Yunhong Nov 2024

Transient Electromagnetic Numerical Simulation Based On The Transformer Neural Network, Wang Yunhong

Coal Geology & Exploration

Objective The deep learning-based transient electromagnetic (TEM) forward and inverse modeling methods are data-driven, requiring considerable numerical simulation results as supervisory data to train and assess neural networks. The conventional finite-difference time-domain (FDTD) method for TEM numerical simulation necessitates an iterative solution of time-domain Maxwell's equations. Therefore, this method is time-consuming and computationally intensive, failing to meet the data demand of deep learning-based TEM inversion. Methods This study introduced deep learning for TEM numerical simulation. Based on the transformer neural network architecture, a neural network for deep learning-based TEM numerical simulation was designed using an encoder-decoder structure. This neural network …


Evolutionary Pattern And Control Technology Of Mine Pressure When Mining Face For Coal Pillars In Main Roadways Passing Through Abandoned Roadways, Li Zhenhua, Ren Ziyuan, Du Feng, Ren Hao, Wang Wenqiang Oct 2024

Evolutionary Pattern And Control Technology Of Mine Pressure When Mining Face For Coal Pillars In Main Roadways Passing Through Abandoned Roadways, Li Zhenhua, Ren Ziyuan, Du Feng, Ren Hao, Wang Wenqiang

Coal Geology & Exploration

Objective With the adjustment of the mining face layout in mines, the overburden roof of the mining face for coal pillar recovery is frequently difficult to control when the mining face passes through abandoned roadways. Methods To address this challenge, this study investigated the coal pillar mining face outside the No.2 panel in the Zhaogu No.2 Coal Mine in Henan Province, which passes through abandoned roadways. Using methods like theoretical analysis, numerical simulation, and in-situ tests, this study examined the composite structure of the mining face and the broken overburden of abandoned roadways, followed by simulation of the full-cycle evolutionary …


Deep Beam Theory-Based Mechanical Analysis Of Water-Resisting Key Strata Of Coal Seam Floors In A Deep Mining Environment, Wang Bingwen, Zha Wenhua, Lu Haifeng Sep 2024

Deep Beam Theory-Based Mechanical Analysis Of Water-Resisting Key Strata Of Coal Seam Floors In A Deep Mining Environment, Wang Bingwen, Zha Wenhua, Lu Haifeng

Coal Geology & Exploration

Objective An increase in the mining depth of mines poses a more serious threat from highly confined karst water, resulting in water hazards like water inflow and inrushes on the mining faces of coal seams. The key content used to address this issue is to analyze the water pressure resistance of the water-resisting key stratum of the coal seam floor in a deep mining environment. Methods This study simplified a water-resisting key stratum into a rock beam model and then dealt with this model using the deep beam theory in the prediction of water inrushes in deep mining. Specifically, by …


Fracture Mechanical Criteria And Simulation Of Floors With Y-Shaped Branches Of Major Faults In Coal Mines, Li Ang, Sun Jingxin, Zhang Wenzhong, Zhang Zhuang, Yang Yuxuan, Wang Weidong, Lyu Wei, Fan Liuyi Sep 2024

Fracture Mechanical Criteria And Simulation Of Floors With Y-Shaped Branches Of Major Faults In Coal Mines, Li Ang, Sun Jingxin, Zhang Wenzhong, Zhang Zhuang, Yang Yuxuan, Wang Weidong, Lyu Wei, Fan Liuyi

Coal Geology & Exploration

Objective Despite wide distribution, the branches of major faults (also referred to as the fault branches) tend to be overlooked. However, they represent one of the primary causes of water inrush. Methods Under the engineering geological background of the Liuzhuang coal mine in Anhui Province, this study established a fracture mechanical disaster model for fault branches under the impacts of both seepage and stress based on the criteria for compression-shear fracture of rock masses considering the Mohr-Coulomb criterion. Using this model, this study obtained the critical water pressure and the minimum safe distance between the fault branch and the floor's …


Research And Application Of The Seismic Exploration Technique Using Reflected In-Seam Waves In Identifying Folds And Faults In Coal Seams, Wu Guoqing Sep 2024

Research And Application Of The Seismic Exploration Technique Using Reflected In-Seam Waves In Identifying Folds And Faults In Coal Seams, Wu Guoqing

Coal Geology & Exploration

Background Accurately identifying subsurface anomalies is crucial to building a geological transparency system in the transformation to intelligent coal mines. The precise exploration of fold anomalies is a challenge of underground geophysical exploration technology, holding great significance for reducing excavation costs, mining difficulties, and safety risks. Objective and Methods Previous in-seam seismic explorations reveal that folds pose significant impacts on the propagation characteristics of in-seam waves. However, conventional inversion techniques of in-seam waves are difficult to distinguish folds from faults. This study constructed numerical models for faults and folds with similar geometric shapes and equal exploration distances. Specifically, the differences …


Structure Optimization Of Foam Generator For Soft Coal Seam And Foaming Effect Simulation, Jin Xin Aug 2024

Structure Optimization Of Foam Generator For Soft Coal Seam And Foaming Effect Simulation, Jin Xin

Coal Geology & Exploration

Objective The application of air screw drilling technology in gas drainage borehole within soft coal seam presents challenges, including severe dust pollution, low drill bit lifespan, and great difficulty in borehole purification. The use of air screw foam drilling technology is an effective way to solve the problem. A foam generator with good foaming performance is one of the keys to implementing the foam drilling technology. However, most current foam generators could not meet the requirements. Methods In response to this issue, a small-sized foam generator was designed based on the spiral foam generator, with an air kinetic energy conversion …


Periodic Roof Deformation And Failure And Associated Water Inflow Characteristics During The Mining Of Typical Coal Seams In The Inner Mongolia-Shaanxi Contiguous Area, Zhou Zhenfang, Dong Shuning, Dong Yang, Luo Shenghu, Xue Jiankun, Wang Zhizhou, Wang Shuxuan, Shang Hongbo, Wang Tiantian, Wang Yutong, Wang Tong Aug 2024

Periodic Roof Deformation And Failure And Associated Water Inflow Characteristics During The Mining Of Typical Coal Seams In The Inner Mongolia-Shaanxi Contiguous Area, Zhou Zhenfang, Dong Shuning, Dong Yang, Luo Shenghu, Xue Jiankun, Wang Zhizhou, Wang Shuxuan, Shang Hongbo, Wang Tiantian, Wang Yutong, Wang Tong

Coal Geology & Exploration

[Objective] The disturbance of coal mine mining damages the aquifer/aquiclude structures of the overburden, causing concentrated water inflow and further affecting safe production in mines. [Methods] Using methods of the physical simulation of similar materials, numerical simulation, and on-site in situ monitoring, this study investigated the water inflow during the mining of the dominant 3-1 coal seam, typically influenced by water in sandstones on the coal seam roof, in the Inner Mongolia-Shaanxi contiguous area. By comparing the measured data of mines with similar geological and mining conditions in the surrounding area, this study delved into the periodic evolutionary patterns of …


Mechanical Characteristics And Fracture Propagation Mechanism Of Deep Coal Reservoirs In The Shenfu Block, Mi Honggang, Wu Jian, Peng Wenchun, Xu Lifu, Li Yong Aug 2024

Mechanical Characteristics And Fracture Propagation Mechanism Of Deep Coal Reservoirs In The Shenfu Block, Mi Honggang, Wu Jian, Peng Wenchun, Xu Lifu, Li Yong

Coal Geology & Exploration

[Objective] Clarifying the mechanical properties and in-situ stress distributions of coal seams, along with the mechanisms behind their control over the morphologies and propagation behavior of artificially induced fractures, is crucial to the fracturing design, well pattern deployment, and coalbed methane (CBM) production of deep coal seams. [Methods] This study investigated the Nos. 8 and 9 coal seams of the Taiyuan Formation in the Shenfu block in the northern portion of the eastern margin of the Ordos Basin. Using data from sonic logging, density logging, injection/falloff well tests, and production, this study systematically analyzed the mechanical …