Sustainability Commons^™

Fracture Structure Of The Overburden In The Layered Mining Of Extremely Thick Coal Seams: Developmental Patterns Of Caving Zones And Hydraulically Conductive Fracture Zones And Fracture Characteristics, Zhang Xin, Chen Youkuo, Meng Hailun, Qin Qifa, Cheng Xianggang, Huang Rongjie, Dong Hairui, Sun Wenbin, Qiao Wei

Coal Geology & Exploration

Objective The Zhunnan Coalfield, a coalfield on the southern margin of the Junggar Basin in Xinjiang, boasts abundant coal resources. However, water hazards in mines severely constrain the safe and efficient coal production in the coalfield. Since hydraulically conductive fractures in roofs serve as primary hydraulically conductive channels formed in the mining of the mining face, it is particularly crucial to investigate the developmental patterns of these fractures during the layered mining of extremely thick coal seams. Methods This study explored the (9-15)08 mining face of the Liuhuanggou Coal Mine in Xinjiang. Using ground exploration holes and borehole televiewers, this …

An Integrated Ecosystem Monitoring Technology For Coal Mining Subsidence Areas And Its Application In The Shendong Mining Area, Cheng Yang, Liu Wei, Zhang Na, Li Guanjie, Liu Kai, Zhang Chengye, Li Jun

Coal Geology & Exploration

Background The ecosystem monitoring of arid and semi-arid coal mining subsidence areas acts as a significant prerequisite for regional ecosystem conservation and management, holding critical significance for accelerating green mine construction. Methods Based on the Chinese government's regulatory requirements for mine ecosystems, this study analyzed the difficulties in ecosystem monitoring in the coal mining subsidence area of the Shendong mining area (also referred to as the Shendong coal mining subsidence area). By detailing the integrated coal-rock-water-soil-air-vegetation-carbon monitoring technology system, this study determined the factors, principal methods, and technology roadmap for the integrated ecosystem monitoring in the Shendong coal mining subsidence …

Predicted Water Yield Of Open-Pit Metal Mines Based On A Bi-Rnn And Gms Coupling Model, Zhao Yuxing, Li Xiangwen

Coal Geology & Exploration

Objective Accurately predicting water yield of mine before mining can provide directive guidance for preventing potential water hazards and ensuring safe production. Methods To enhance the prediction accuracy and stability of water yield of open-pit metal mines, for which atmospheric precipitation acts as the primary recharge source of water, this study developed a prediction model that coupled a bidirectional recurrent neural network (Bi-RNN) and the Groundwater Modeling System (GMS) software. Specifically, based on historical forecasted precipitation data provided by the Global Forecast System (GFS), the fluctuation pattern of differences between predicted forecasted and actual precipitation was analyzed. After being corrected …

An Experimental Study Of The Application Of The Spectral Acoustic Method To The Advance Detection Of Geologic Structures In Tunnelling Working Site, Zhang Jianguo, Feng Zhicheng, Wei Fengqing, Ma Ji, Zhao Kai, Wang Man, Guo Minggong, Шилов Владимир Иванович

Coal Geology & Exploration

Objective The practice of coal mine production has proved that the vast majority of coal and gas outbursts are controlled by geological structures, and mainly occur in tunnelling working site. Therefore, continuous advanced detection of geological structures is an important technical means to prevent and control coal and gas outbursts in tunnelling working site, and is of great significance to ensure safe production in mines. Methods Based on the research results of spectral acoustic method in Russia for many years, the resonance phenomenon generated at the weakened contact surface of the roof rock layer by the artificial acoustic signal excited …

Application Of Microseismic Monitoring In The Optimization Of Control Strategy For Roofs Composed Of Composite Hard Sandstone Masses, Zhang Yin, Li Jiajun, Zhao Qian, Yang Chenchen, Liu Jiaqi, Zhou Yu

Coal Geology & Exploration

Objective With a gradual increase in the coal mining depth in China, the movement of overlying thick and hard rock layers exerts increasingly complex impacts on the mine pressure. Methods In the Ordos area, the overburden of the mining face of most mines hosts composite hard sandstone masses, serving as key layers characterized by considerable thicknesses, high hardness, and close proximity. Results and Conclusions As a result, the risks of mine earthquakes and dynamic manifestation co-exist in the mining face. With the roof of mining face11-3106 in a coal mine within the Ordos mining area as the engineering background, this …

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 …

Biomimetic Technologies For Drill Rods: Advances In Research And Development Trends, Wang Chuanliu, Ju Pei

Coal Geology & Exploration

Significance Drill rods are recognized as core tools in drilling engineering, and their performance exerts a significant influence on drilling efficiency and safety. Over recent years, applying biomimetic technologies to drill rod design has gradually emerged as a hot research topic. By imitating the remarkable structures, morphologies, and material properties of living organisms in nature, biomimetic technologies provide entirely new philosophies and approaches for the innovative design of drill rods. Advances This study summarizes the advances in research on biomimetic technologies for drill rods in terms of the biomimetic design of structures, morphologies, and materials. Regarding the biomimetic design of …

A Dc-Unet-Based Image Processing Method For Detecting Fractures Along Roadway Sections Of Coal Mines, Dong Zheng, Zhang Xuhui, Yang Wenjuan, Kang Le, Tang Duwei, Tian Chenhui

Coal Geology & Exploration

Objective Detecting fractures along roadway sections of coal mines allows for the characterization of the geologic conditions of roadways, thus providing guidance for roadway tunneling and support engineering. However, conventional image processing methods for fractures along roadway sections are susceptible to complex environments in underground coal mines, exhibiting a low fracture detection efficiency. Methods This study proposed a novel image processing method for detecting fractures along roadway sections based on a DC-UNet model. This method can be deployed on a mobile terminal and an embedded device, thereby allowing for real-time and effective detection of fractures along roadway sections and enhancing …

Development Of A Power Recovery-Based Dynamic Loading System For Full-Size Drill Rods In Coal Mines, Zhang Jing, Wang Jie

Coal Geology & Exploration

Objective This study aims to simulate the actual forces applied to drill rods during the borehole drilling for gas drainage from underground coal mines to satisfy the requirements of drill rods’ fatigue tests. Methods This study designed a dynamic loading system for full-size drill rods in coal mines. This system consists of a drill rod loading platform, a hydraulic pump unit with power recovery, and a measurement and control system, allowing for the composite loading of dynamic torque, axial force, and radial displacement on drill rods of different specifications. In this system, torque is loaded to drill rods using the …

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 …

Microscopic Fracture Characterization And Permeability Evolutionary Patterns Of Granites Under Cyclic Thermal Shock, He Jiangfu, Ren Chengcheng, He Kun, Yu Qihang, Li Xinru, Deng Xu

Coal Geology & Exploration

Objective This study aims to reveal the microscopic damage characteristics and permeability evolutionary patterns of high-temperature granite reservoirs fractured under cyclic thermal shock produced by low-temperature fluids like drilling fluids and circulating heat recovery media in the exploitation process of the enhanced geothermal systems (EGSs). Methods Using experiments on the fracturing characteristics of high-temperature granites under the conditions of varying cooling methods, numbers of thermal shock cycles, and cooling temperatures, this study determined microstructural characteristic parameters such as compressional wave (P-wave) velocity, pore volumetric fraction, and fractal dimension of granites across a temperature range of 25 to 700 ℃ under …

Identifying The Lithologies And Thicknesses Of Coal Seam Roofs And Floors Based On Multiparameter Logging Of Boreholes, Li Zhe, Gao Baobin, Lei Wenjie, Li Donghui, Li Zixin

Coal Geology & Exploration

Background In the process of coal mining, effective exploration methods for stratigraphic characteristics are crucial to underground operations. The reason is that the accurate stratigraphic characteristics of coal seams, along with the surrounding rocks of coal seam roofs and floors, facilitate the treatment of gas in coal seams, thereby ensuring safe and efficient coal mining. Methods Based on the multiparameter logging of boreholes crossing strata in a bottom drainage roadway, this study highlighted the lowstand, upgoing borehole trajectories, as well as the variations in parameters including natural gamma rays, spontaneous potential, and resistivity. By comprehensive comparison of the trajectories, video-derived …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Influence Mechanisms Of Dynamic Metamorphism On The Evolution Of Micro/Nano Pore Structures In Tectonically Deformed Coals, Liu Hewu, Lyu Xiaoxue, Hou Chenliang, Xiong Zuopeng

Coal Geology & Exploration

Objective Micro/nano pore structures in coals act as a significant space for gas occurrence. Exploring the evolutionary mechanisms of micro/nano pore structures in tectonically deformed coals (TDCs) under the influence of dynamic metamorphism assists in gaining a deep understanding of the mechanisms underlying coal and gas outbursts. Methods Using CO₂ adsorption experiments, Fourier transform infrared (FTIR) spectroscopy, and molecular dynamics simulations, this study investigated the evolutionary characteristics and mechanisms of micro/nano pore structures in different TDCs occurring within the No.72 coal seam of the Qi’nan Coal Mine in Suzhou Province. Results and Conclusions The results indicate that with enhanced …

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 …

Construction And Correction Of A 3d Digital Twin For A Complex Gangue-Bearing Coal Seam, Zhang Meichen, Zhao Lijuan, Wang Yadong, Zhang Kai

Coal Geology & Exploration

Objective 3D digital twin for complex gangue-bearing coal seams are designed to achieve an information-based description of physical coal seams and faithfully map their virtual forms. digital twin is identified as a prerequisite for exploring the efficient cutting of intelligent shearers while providing an effective data guarantee for achieving unmanned mining. Methods Using data on samples from the mining face of coal seam 17 in the Yankuang Energy Group Co., Ltd. Shandong Province, this study proposed a methodology that integrates more information about the geological structural conditions of coal seams. Specifically, digital twining of iron sulfide nodules was performed using …

A Calculational Model For 3d Fault Complexity Based On Curvature Analysis And Fractal Dimensions, Yan Junsheng, Liu Zaibin, Fan Tao, Yang Hui, Liu Wenming, Du Wengang, An Lin, Liu Chenguang, Wang Xiaohui

Coal Geology & Exploration

Objective and Methods Faults are identified as one of the most threatening geological structural factors among hidden disaster-causing factors in coal mines. However, the 3D quantitative assessment of them remains challenging. Considering that existing quantitative indicators fail to fully reflect fault morphologies and there is a lack of 3D methods, this study proposed a calculational model for 3D fault complexity based on curvature analysis and fractal dimensions. This model improved the morphologies of traditional measurement volumes of fractal dimensions by employing the Delaunay tetrahedralization algorithm, thus effectively reducing the invalid values in calculating the 3D fractal dimensions of faults. Moreover, …

Exploration Of The Impacts Of Cement Sheath On Casing Stress Based On The Arching Effects Of Formations, An Fengchen, Miao Zhibo, Meng Siwei, Wei Ziying, Zhang Xiao, Zeng Jiaming, Wang Xiaohua

Coal Geology & Exploration

Objective With the growth in the demand for natural oil and gas and the technological progress of their production, the oil and gas well depths have been constantly setting new records. The increase in the depth corresponds to sharply increasing in-situ stress, leading to increasingly severe damage to the casing of ultradeep oil and gas wells. To enhance the bearing capacity of the casing under high in-situ stress, high-strength casing with a large wall thickness is typically employed, a measure which has been proved, however, less effective. Methods This study established a finite element model of the casing-cement sheath-formation system …

Hydrochemical Characteristics And Component Sources Of Water In Underground Reservoirs In The Daliuta Coal Mine, Zhang Haitao, Jiang Binbin, Zhang Haiqin, Li Peng, Wu Min, Hao Jingwei, Hu Yutian

Coal Geology & Exploration

Objective Underground reservoirs in coal mines are capable of storing and purifying mine water. A deep understanding of the hydrochemical characteristics and formation mechanisms of water in underground reservoirs is identified as an important prerequisite for large-scale development of technologies for mine water treatment. Methods This study investigated the underground reservoirs in the Daliuta Coal Mine within the Shendong area by testing and analyzing their influent and effluent water samples. Using methods such as the ion ratio method, multivariate statistical analyses (e.g., correlation analysis and principal component analysis (PCA)), and the positive matrix factorization (PMF) model, this study delved into …

Sustainability Assessment Of Photovoltaic Cells In Cross-Functional Applications, Achyuth Ravilla

Dissertations and Theses

Achieving the G7 countries' net-zero emissions target by 2050 requires integrating photovoltaic (PV) systems into diverse cross-functional applications that support sustainable energy transitions across multiple sectors. This dissertation explores the economic and environmental sustainability of three such applications: agrivoltaics, lower-dimensional materials in perovskite solar cells, and PV-electrochemical water-splitting technologies for hydrogen production. Employing life cycle assessment (LCA) and techno-economic analysis (TEA), we address the knowledge gap in comprehensive evaluations of PV-integrated solutions.

The first chapter assesses agrivoltaic systems (AVS), which combine PV systems with agriculture to mitigate land-use conflicts while enhancing food and energy production. Findings indicate that AVS designs, …

Techniques For Coal Resource Conservation During The Ecological Restoration Of Alpine Mining Areas On Plateaus, Li Congcong, Wang Tong, Zhao Xin, Wang Weichao, Liang Zhenxin

Coal Geology & Exploration

Objective The prolonged coal mining of the Muli coalfield, located in an alpine region in the eastern Qinghai-Tibet Plateau, has posed many ecological challenges, which especially include the presence of considerable quantities of disturbed coal resources in open-pit mining areas. This study aims to achieve scientific and effective coal resource conservation during the ecological restoration of coal mines. Methods Focusing on the Jvhugeng mining area of the Muli coalfield, this study investigated the destruction characteristics of the coal resources in the open-pit mining area. From the perspective of geological mechanisms behind the destruction, this study artificially constructed the roofs of …

3d Reconstruction Of Surface Temperature Field In Spontaneous Combustion Coal Gangue Dump Fire Area And Its Practice, Shao Zhenlu, Zhang Huisong, Deng Rong, Yang Tong, Ma Dong

Coal Geology & Exploration

Objective The spontaneous combustion of coal gangue dumps has severely damaged the ecological environment and affected the production safety, which has become a bottleneck in the process of ecological civilization construction in China. In order to formulate a fire extinguishing plan and implement a fire extinguishing project, it is very important to accurately detect the fire area of the spontaneous combustion coal gangue dump. Methods Herein, the idea of detecting the three-dimensional distribution of high-temperature areas using unmanned aerial vehicle (UAV) based thermal infrared oblique photogrammetry technology was proposed. Meanwhile, the multi-scale Gaussian filtering detail enhancement technology for thermal infrared …

Detrital Zircon Ages Of The Permian Coal-Bearing Rock Series In The Zhongtiao Mountain Area And Their Sedimentological Constraints On Regional Tectonic Activity, Wu Fang, Li Zhenhong, Jing Xianghui, Kou Linlin, Du Zhuang, Liu Bohua

Coal Geology & Exploration

Objective The changes in the material composition of detrital sediments in a sedimentary basin are intimately associated with the uplift and denudation processes of provenance areas. The southern margin of the North China Craton, a primary tectonic unit of the continental area of China, preserves relatively complete geological records of the Permian. The Zhongtiao Mountain area is located in the core of the Fen-Wei graben system on the southern margin of the North China Craton, with the southern margin of the North China Craton and the adjacent Qinling orogenic belt potentially serving as its provenance areas. Therefore, the Zhongtiao Mountain …

A Smogn-Based Mpso-Bp Model To Predict The Height Of A Hydraulically Conductive Fracture Zone, Liu Qi, Liang Zhihao, Zi Jianxiao

Coal Geology & Exploration

Objective The height of a hydraulically conductive fracture zone, a significant factor influencing roof water inrushes and groundwater resource loss, is identified as a research focus of the prevention and control of mine water disasters. Methods To accurately predict the heights of hydraulically conductive fracture zones in coal seam roofs, five parameters were selected as the primary factors influencing hydraulically conductive fracture zones the mining depth: mining height, coal seam inclination, the length of the mining face along its dip direction, proportional coefficient of hard rocks (i.e., the ratio of the cumulative thickness of hard rocks within the statistical height …

Acoustic Velocity Inversion Based On Convolutional Autoencoder Embedded With Fourier Neural Operator, Li Chen, Zhao Haixia, Bai Zhaowei, Hao Yufan

Coal Geology & Exploration

Background Seismic wave inversion serves as an effective method for obtaining the characteristics of structures, lithology, and physical properties of subsurface media using the arrival times, amplitude, and waveforms of seismic waves. Seismic inversion methods based on wave equations iteratively update model parameters using forward modeling. This generally involves extensive numerical simulations and optimization calculations, requiring large quantities of computational resources and time. In recent years, neural operators for deep learning, represented by the Fourier neural operator (FNO), have gained widespread attention. However, the original FNO structure fails to effectively learn the wavefield information with sharp changes in geological structures …

Intelligent Noise Suppression For 3d Post-Stack Seismic Data Of The Junggar Basin, Mao Haibo, Zhou Xin, Li Xiaofeng, Pan Long, Lin Juan, Liu Dawei, Wang Xiaokai

Coal Geology & Exploration

Objective The Junggar Basin is recognized as a significant petroliferous basin in China, and its hydrocarbon exploration targets have shifted to deeper strata. However, the 3D seismic data of this basin suffer from low signal-to-noise ratios (SNRs) and high data volumes due to the basin's complex near-surface conditions, the great depths of exploration targets, and seismic data acquisition methods characterized by wide azimuths, broadbands, and high density. This complicates the identification of hydrocarbon exploration targets, rendering the improvement in the quality of the 3D seismic data by noise suppression vitally important. Methods The progress in the deep learning theory and …

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 …

Surfaced-Related Multiple Attenuation Using The Cnn Method In The Nmo Domain, Huang Zhufu, Liu Jianfeng, Fang Wenqian, Fu Lihua

Coal Geology & Exploration

Objective The presence of surface-related multiples results in a lower accuracy in seismic data interpretations, and the effective multiple attenuation is a key step in seismic data processing. Multiples are coherent noise signals with similar characteristics to effective signals. It is difficult impossible to distinguish multiple signals from full-wave field data using a traditional convolutional neural network (CNN). Additionally, since the surface-related multiples vary significantly with surveyed areas, the CNN method will face more severe challenges when being transferred to other networks. Methods This study developed a CNN method based on the normal moveout correction (NMO) domain by introducing physical …

Impacts And Regulation Mechanisms Of Phase-Change Wall Microspheres On Cement Slurry Performance In Well Cementing, Zheng Mingming, Wu Zurui, Yan Shichun, Hu Yunpeng, He Juan, Zhang Yawei, Xiong Liang, Zhu Chengtao

Coal Geology & Exploration

Objective The current design of low-heat cement slurries prepared by adding microspheres with phase change materials as wall materials for well cementing in strata bearing natural gas hydrates (NGHs) fails to fully account for the impacts of the particle size and mass fraction of the microspheres on the performance of cement slurries. This leads to impaired cement slurry performance and increased costs, further inducing many problems with well cementing quality. Hence, it is significant to analyze the impacts and controlling mechanisms of the microspheres on cement slurry performance. Methods To eliminate the interference of the heat storage effect of the …

An Intelligent Identifying-While-Drilling Method For Geological Features Of Roof Strata In Coal Roadways Based On A 1dcnn-Bilstm-Cbam Model, Lei Zhiyong, Wang Jiawen, Fan Dong, Lu Feifei, Chen Weiming

Coal Geology & Exploration

Objective Most roof accidents in coal roadways occur in potential caving zones such as primary fissure-bearing zones and rock fracture zones. A significant approach to preventing roof accidents is to understand the geological features of roof strata in an accurate and timely manner and optimize support schemes and parameters of roofs. However, current methods for identifying the geological features of roof strata in roadways suffer from issues such as slow identification speeds, low efficiency, and high costs, thus failing to meet the demand for safe, efficient, and intelligent coal mining. Methods This study proposed a neural network model based on …