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Full-Text Articles in Engineering

Factors Influencing The Production Of Coalbed Methane From Deep Reservoirs, Wang Zhenzhi, Fu Xuehai, Pan Jienan, Jin Yi, Wang Haichao Feb 2025

Factors Influencing The Production Of Coalbed Methane From Deep Reservoirs, Wang Zhenzhi, Fu Xuehai, Pan Jienan, Jin Yi, Wang Haichao

Coal Geology & Exploration

Objective The production characteristics of coalbed methane (CBM) from deep reservoirs differ significantly from those of CBM from shallow reservoirs. Key challenges in deep CBM production include maintaining reservoir permeability or minimizing permeability loss, enhancing CBM (CH4) desorption efficiency, and accurately predicting the laws of CH4 diffusion. There is an urgent need to overcome these challenges through technological innovation and theoretical research. Methods This study systematically analyzed the advances in domestic and international research on coal reservoir permeability, CBM desorption, and CBM diffusion. By integrating the classification of production stages of deep coal reservoirs with the dominant …


Migration Characteristics And Storage Forms Of Liquid And Supercritical Co2 In Saline Aquifers, Peng Xiyi, Wang Yanyong, Li Song, Wang Xiaoguang, Cui Guodong, He Yongming Feb 2025

Migration Characteristics And Storage Forms Of Liquid And Supercritical Co2 In Saline Aquifers, Peng Xiyi, Wang Yanyong, Li Song, Wang Xiaoguang, Cui Guodong, He Yongming

Coal Geology & Exploration

Objective CO2 storage in saline aquifers serves as a critical technology used to dramatically reduce greenhouse gas emissions. Owing to the low-temperature marine environment and the pressure from overlying seawater, shallow offshore saline aquifers exhibit significantly different temperature and pressure conditions compared to onshore saline aquifers at equivalent burial depths, allowing CO2 to occur in a liquid state. Compared to supercritical CO2, liquid CO2 features higher density, viscosity, and solubility in formation water, which affect the CO2 migration and storage processes. Previous studies focus primarily on supercritical CO2, lacking a deep understanding …


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, …


Deformation Characteristics And Influential Factors Of The Surface Uplift Of Closed Mines, Luo Jin, Li Yingming, Guo Qingbiao, Zhao Guangming Feb 2025

Deformation Characteristics And Influential Factors Of The Surface Uplift Of Closed Mines, Luo Jin, Li Yingming, Guo Qingbiao, Zhao Guangming

Coal Geology & Exploration

Objective The residual surface deformations of closed mines exhibit prolonged duration and complex evolutionary processes, potentially leading to unconventional phenomena like surface uplift, which affects the re-exploitation and reutilization of closed mines. Methods This investigated a mining area in Huainan, Anhui Province as an example to explore the deformation mechanisms, characteristics, and influential factors of the surface uplift of closed mines. Through numerical simulations, this study analyzed the propagation process of surface uplift with an increase in the groundwater level. Accordingly, this study investigated the quantitative impacts of the mining height, groundwater level, and rock strength of the caving zone …


Strength And Damage Characteristics Of Cemented Gangue Backfill During Saturated Immersion, Yu Xiang, Yang Ke, He Xiang, Hou Yongqiang, Wen Zhiqiang, Zhang Lianfu Feb 2025

Strength And Damage Characteristics Of Cemented Gangue Backfill During Saturated Immersion, Yu Xiang, Yang Ke, He Xiang, Hou Yongqiang, Wen Zhiqiang, Zhang Lianfu

Coal Geology & Exploration

Objective Under the influence of backfill slurry, water inrushes in mining face, and water accumulation in goaves, the water content in cemented gangue backfill varies with the immersion time, thus altering the bearing performance of the backfill. Investigating the strength and damage characteristics of cemented gangue backfill during saturated immersion is crucial for maintaining the stability of the backfill and ensuring the safety of coal mines. Methods Using uniaxial compression tests and scanning electron microscopy (SEM) of cemented gangue backfill during saturated immersion, this study analyzed the law of changes in the backfill strength under varying immersion times. Based on …


Response Characteristics Of The Orthogonal Antennas Of Electromagnetic Azimuthal Resistivity Measurement While Drilling (Mwd) Tool For Coal Mining, Chen Gang Feb 2025

Response Characteristics Of The Orthogonal Antennas Of Electromagnetic Azimuthal Resistivity Measurement While Drilling (Mwd) Tool For Coal Mining, Chen Gang

Coal Geology & Exploration

Objective and Methods This study aims to determine the factors influencing the detection performance of the electromagnetic azimuthal resistivity measurement while drilling (MWD) tool for coal mining in horizontal wells. Through finite element numerical simulations, this study conducted boundary detection using orthogonal coupling coils with multiple frequencies and coil pitches. This allowed for determining the optimal asymmetric arrangement of coils, as well as the optimal working parameters of frequency, source-detector separation distance, and coil pitch suitable for high-resistivity coal seams. Results and Conclusions The comparative study of orthogonal and inclined coils reveals that in the case of directional signals of …


A Method For High-Accuracy Localization Of Microseismic Sources In Mines Based On Finite Element Simulation, Ning Dianyan, Zhu Kaipeng, Zhu Yongsheng, Yuan Shuxia, Zhou Zhenfang Feb 2025

A Method For High-Accuracy Localization Of Microseismic Sources In Mines Based On Finite Element Simulation, Ning Dianyan, Zhu Kaipeng, Zhu Yongsheng, Yuan Shuxia, Zhou Zhenfang

Coal Geology & Exploration

Objective and Methods Microseismic monitoring technology for mines can reflect the deformations and failure of rock layers by capturing low-frequency vibration signals their internal structure generated during the stress-induced deformation and failure of them. Accordingly, water inrush warnings and geologic hazard prediction can be achieved. Acoustic source localization, allowing for the localization of energy release and the early warning of potential hazards, plays a key role in this technology. Presently, when used for acoustic source localization, the time difference of arrival (TDOA) method is facing issues including high algorithmic complexity, significant impacts of probe arrangement on the localization accuracy, and …


A Temporal Fusion Method For Modeling The Rate Of Penetration During Deep Geological Drilling, Zhou Yang, Lu Chengda, Wu Min, Chen Xin, Yao Ningping, Song Haitao, Zhang Youzhen Feb 2025

A Temporal Fusion Method For Modeling The Rate Of Penetration During Deep Geological Drilling, Zhou Yang, Lu Chengda, Wu Min, Chen Xin, Yao Ningping, Song Haitao, Zhang Youzhen

Coal Geology & Exploration

Objective Given that the rate of penetration (ROP) serves as a key indicator of drilling efficiency, constructing an accurate ROP model holds great significance for optimizing drilling processes and reducing drilling costs. However, deep geological drilling faces challenges such as nonlinearity, non-convex optimization, multiple operating conditions, and temporal variations. Consequently, traditional modeling methods are difficult to adapt to complex geologic environments. Methods To address these challenges, this study proposed a fusion method combined with temporal regulation for ROP modeling: the SVR-MDBO method. Initially, a basic ROP model was constructed using support vector regression (SVR) to solve the nonlinear problem caused …


Frequency-Domain Induced Polarization Responses Of Water-Bearing Anomalous Bodies In The Roadway Tunneling Direction In Coal Mines, Hu Xiongwu, Hu Yuanrong, Wu Rongxin, Yu Hao Feb 2025

Frequency-Domain Induced Polarization Responses Of Water-Bearing Anomalous Bodies In The Roadway Tunneling Direction In Coal Mines, Hu Xiongwu, Hu Yuanrong, Wu Rongxin, Yu Hao

Coal Geology & Exploration

Objective A frequency-domain induced polarization (FDIP) method enables the observation of critical electrical parameters such as frequency dispersivity and complex resistivity of geological bodies, mitigating the multiplicity of solutions in the interpretations of electrical anomalies. This method has emerged as a primary technique for electric method-based advance water detection during roadway tunneling in coal mines. However, the FDIP method primarily focuses on data observation in the direction opposite to roadway tunneling, exhibiting a limited capacity to capture geoelectric information in the roadway tunneling direction. This leads to practical challenges such as unclear orientations of water-bearing anomalous bodies. Therefore, exploring the …


Prospects For Mine Geological Work In The Intelligence Age: Architecture Of The Intelligent Geological Guarantee Technology System For Mine Exploitation, Xia Yucheng, Sun Xueyang, Miao Lintian, Guo Chen, Du Rongjun Jan 2025

Prospects For Mine Geological Work In The Intelligence Age: Architecture Of The Intelligent Geological Guarantee Technology System For Mine Exploitation, Xia Yucheng, Sun Xueyang, Miao Lintian, Guo Chen, Du Rongjun

Coal Geology & Exploration

Background and Significance In response to the serious challenges posed by the goals of peak carbon dioxide emissions and carbon neutrality, the intelligentization of coal mines is an inevitable course and a significant sign of the high-quality, sustainable development of the coal industry in the New era. Mine geological work, providing geological foundation and guarantee for underground coal mining, plays an increasingly significant role in the transformation and upgrading of the coal industry for high-quality development. Constructing an intelligent geological guarantee technology system for coal mining by combining mine geology with artificial intelligence (AI) can provide a comprehensive, whole-process geological …


An Analytical Method For The Desorption Superposition Effect In Commingled Production Of Coalbed Methane And Its Application: A Case Study Of The Xiaotun Mine Field In Western Guizhou Province, China, Guo Chen, Ji Yan, Zhao Chenyi, Lu Lingling, Yu Xinhang, Gao Junzhe, Li Houqiang, Zhang Xuyang, Wang Xiang, He Hongbin, Zhang Runhan Jan 2025

An Analytical Method For The Desorption Superposition Effect In Commingled Production Of Coalbed Methane And Its Application: A Case Study Of The Xiaotun Mine Field In Western Guizhou Province, China, Guo Chen, Ji Yan, Zhao Chenyi, Lu Lingling, Yu Xinhang, Gao Junzhe, Li Houqiang, Zhang Xuyang, Wang Xiang, He Hongbin, Zhang Runhan

Coal Geology & Exploration

Objective The commingled production of coalbed methane (CBM) serves as a significant means to increase single-well production. However, production practices reveal that the commingled production of CBM exhibits complex and varied effects and controlling factors, facing technical challenges of identifying gas-producing contributions, predicting gas-producing potential, and optimizing pay interval combinations. The superposition of desorption for gas production among different coal seams determines whether high CBM production can be achieved using commingled production. Methods This study proposed an analytical method for the desorption superposition effect in the commingled production of CBM, involving determining desorption sequences, analyzing the superposition of desorption intervals …


Optical-Electrical-Acoustic Wave Multiparameter Response Characteristics Of Typical Rocks In Coal-Bearing Strata Throughout The Loading Process, Zhang Pingsong, Liu Chang Jan 2025

Optical-Electrical-Acoustic Wave Multiparameter Response Characteristics Of Typical Rocks In Coal-Bearing Strata Throughout The Loading Process, Zhang Pingsong, Liu Chang

Coal Geology & Exploration

Objective The deformations and rupture of rocks under loading will cause potential changes in parameters. Dynamic parameter capture assists in characterizing the generation, propagation, and closure processes of fractures, serving as a significant method for assessing rock quality. Methods Using a multiparameter test system, this study synchronously acquired strain measured using distributed optic fibers, electrode current, and compressional wave (P-wave) velocities of rock specimens under uniaxial loading. Accordingly, this study determined strength vs. parameter characteristic relationship graphs and parametric tomography results, finely describing the multiparameter spatiotemporal evolutionary characteristics of three typical rocks (i.e., sandstone, limestone, and mudstone) throughout the loading …


A U-Net-Based Denoising Method For Semi-Airborne Transient Electromagnetic Data And Its Application, Liu Dong, Feng Hao, Wang Yongxin, Zhou Xiaosheng, Yao Yuhong, Sun Huaifeng Jan 2025

A U-Net-Based Denoising Method For Semi-Airborne Transient Electromagnetic Data And Its Application, Liu Dong, Feng Hao, Wang Yongxin, Zhou Xiaosheng, Yao Yuhong, Sun Huaifeng

Coal Geology & Exploration

Objective and Methods The semi-airborne transient electromagnetic (SATEM) method, an efficient geophysical exploration technique, has been extensively applied to mineral resource exploration, groundwater surveys, and geothermal resource surveys. However, the collected data are frequently susceptible to noise interference, significantly affecting the accuracy of subsequent data processing and interpretation. To address issues such as residual noise and the loss of effective signals, enhance denoising effects, and reduce the influence of subjective factors, this study proposed a denoising method for SATEM data based on the U-Net deep learning architecture (also referred to as the U-Net-based method) by applying U-Net to SATEM data …


China’S Cbm Exploration And Production And Associated Technological Advancements: A Review And Reflections, Ye Jianping Jan 2025

China’S Cbm Exploration And Production And Associated Technological Advancements: A Review And Reflections, Ye Jianping

Coal Geology & Exploration

Objective and Methods Based on extensive scientific and technical literature and technical data on coalbed methane (CBM) exploration and production projects, this study conducted a comparative analysis of the development process and latest advances in China’s critical technologies for CBM exploration and production and reviewed the CBM exploration and production history of this country over the past three decades. Accordingly, this study discussed the theoretical and technical challenges in CBM exploration and production and proposed future development directions. Advances The results indicate that the insights into conversion between adsorbed and free deep CBM prove to be a significant theoretical understanding. …


Critical Technologies And Geology-Engineering Integration Practices For Deep Cbm Production In The Yanchuannan Cbm Field, Chen Zhenlong, Wang Yunhai, Liu Xiao, Cui Bin, Yang Song, Li Xin, Fang Qilong Jan 2025

Critical Technologies And Geology-Engineering Integration Practices For Deep Cbm Production In The Yanchuannan Cbm Field, Chen Zhenlong, Wang Yunhai, Liu Xiao, Cui Bin, Yang Song, Li Xin, Fang Qilong

Coal Geology & Exploration

Objective and Methods This study introduces the adjustments for coalbed methane (CBM) production in the Yanchuannan CBM field‒the first deep CBM field in China. Deep CBM production in this CBM field faces challenges including strong heterogeneity of reservoirs, single arrangement mode of production well patterns, low applicability of conventional hydraulic fracturing, excessively long conventional production cycles, and a high proportion of inefficient wells. To address these challenges, a production capacity construction model for efficient deep CBM production of the field was developed through in-depth geology-engineering integration. Results and Conclusions The results indicate that the production capacity construction process of the …


Connotation, Research Status, And Development Directions Of Clean Coal Geology In China, Tang Yuegang, Wang Shaoqing, Wang Xiaoshuai, Guo Xin, Wang Yafeng, Xue Liping, Harold H. Schobert Jan 2025

Connotation, Research Status, And Development Directions Of Clean Coal Geology In China, Tang Yuegang, Wang Shaoqing, Wang Xiaoshuai, Guo Xin, Wang Yafeng, Xue Liping, Harold H. Schobert

Coal Geology & Exploration

Objective The exploration and assessment of low-carbon, zero-emission, and maximized utilization of coal resources, emerge as a focus of coal geology in the 21st century. [Research Advances] Based on the research content of coals and coal geology, along with the domestic and international development trends of clean coal technology (CCT), this study defines clean coal geology in the broad and narrow sense. Clean coal geology in the narrow sense focuses on the geological and geochemical issues related to efficiency enhancement and emission reduction in coal processing and utilization. In contrast, clean coal geology in the broad sense emphasizes …


Table Of Contents, The Editors Jan 2025

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Advances And Trends Of Modern And Contemporary Research On The Geology Of Coal-Measure Minerals In China, Qin Yong Jan 2025

Advances And Trends Of Modern And Contemporary Research On The Geology Of Coal-Measure Minerals In China, Qin Yong

Coal Geology & Exploration

Background Coal-measure minerals (CMMs) play a significant role in ensuring the safe supply of mineral resources in China. Reviewing the advances and trends of research on the geology of CMMs in China holds great historical significance and practical value while potentially providing some insights into subsequent research. Advances Based on textual research and the analysis of logical relations, this study generalized the advances in research on the geology of CMMs in China into four aspects. (1) Increasingly improved geological theory system of CMMs: China’s classic theoretical system of coal field geology was formed in the second half of the 20th …


Gas Drainage And Utilization In Coal Mines In China: History, Technological Advances, And Prospects, Li Guofu, Li Chao, Zhang Bichuan, Xu Yun, Wang Zheng, Zhou Xianjun Jan 2025

Gas Drainage And Utilization In Coal Mines In China: History, Technological Advances, And Prospects, Li Guofu, Li Chao, Zhang Bichuan, Xu Yun, Wang Zheng, Zhou Xianjun

Coal Geology & Exploration

Objective and Methods To promote the research and application of gas drainage and utilization technologies for coal mines, this study systematically summarizes the history of China’s coal mines transitioning from gas pumping to gas drainage, the accurate and effective gas drainage technologies for typical coal mining areas in China, and the latest applications of technologies related to safe gas gathering and transportation, as well as the utilization of gas with a full range of concentrations. This study aims to provide a reference for accelerating the advancement in gas drainage and utilization technologies for coal mines, achieving methane emission reduction, and …


Key Experimental Technologies And Their Development Directions For The Exploration And Production Of Deep Coalbed Methane, Yan Xia, Xu Fengyin, Xiong Xianyue, Wang Feng, Li Chunhu, Zhang Jiyuan, Xu Borui, Cheng Qianhui, Hu Xiong, Zhu Xueguang, Liang Wei, Yuan Pu, Feng Yanqing, Wei Zhenji Jan 2025

Key Experimental Technologies And Their Development Directions For The Exploration And Production Of Deep Coalbed Methane, Yan Xia, Xu Fengyin, Xiong Xianyue, Wang Feng, Li Chunhu, Zhang Jiyuan, Xu Borui, Cheng Qianhui, Hu Xiong, Zhu Xueguang, Liang Wei, Yuan Pu, Feng Yanqing, Wei Zhenji

Coal Geology & Exploration

Objective Deep coalbed methane (CBM) production enjoys advantages including rapid gas shows, high single-well yield, and continuous resource distribution, which establish deep CBM as a significant target for reserve growth and production addition of natural gas. However, the exploration and production of deep CBM are still confronted with many technical challenges, and there is a lack of studies on key experimental technologies related to the geological characteristics and engineering assessment of deep CBM reservoirs, the occurrence characteristics and production mechanisms of gas and water, the formulation of production systems, and methods for enhanced CBM recovery. Advances in Research Given the …


Spatiotemporal Evolutionary Patterns Of The Hydrochemistry Of Jurassic Conglomerate Aquifers Under The Influence Of Curtain Walls, Chen Luwang, Wu Minghui, Hou Xiaowei, Hu Yongsheng, Zhang Miao, Cai Xinyue, Yin Xiaoxi, Shi Xiaoping Jan 2025

Spatiotemporal Evolutionary Patterns Of The Hydrochemistry Of Jurassic Conglomerate Aquifers Under The Influence Of Curtain Walls, Chen Luwang, Wu Minghui, Hou Xiaowei, Hu Yongsheng, Zhang Miao, Cai Xinyue, Yin Xiaoxi, Shi Xiaoping

Coal Geology & Exploration

Objective Curtain walls, recognized as a primary project for the prevention and control of water disasters in coal mines, will change the dynamic field of groundwater. Furthermore, their dissolution will affect the chemical field of groundwater, leading to variations in its hydrochemical composition. Methods This study investigated the Jurassic conglomerate aquifers in the Zhuxianzhuang Coal Mine, Huaibei coal field. Based on the statistics of conventional hydrochemical composition, Piper diagrams, ion combination proportions, and principal component analysis (PCA), this study explored the impacts of curtain walls on the hydrochemistry of the aquifers and determined the spatiotemporal hydrochemical evolutionary patterns under the …


A Deep Learning-Based Method For The Intelligent Identification Of The Quantity Of Coals Flushed Out During Borehole Hydraulic Flushing, Li Xiaojun, Zhao Mingyang, Li Miao Jan 2025

A Deep Learning-Based Method For The Intelligent Identification Of The Quantity Of Coals Flushed Out During Borehole Hydraulic Flushing, Li Xiaojun, Zhao Mingyang, Li Miao

Coal Geology & Exploration

Objective Given the inaccurate and low-efficiency manual statistics of the quantity of coals flushed out during borehole hydraulic flushing, this study proposed an intelligent identification method that combines YOLOv8n, ResNet34, and PP-OCRv4 algorithms. Methods First, the first-level detection was completed using the YOLOv8n algorithm, which, combined with the ResNet34 and PP-OCRv4 algorithms via parallel cascade, was then employed to conduct second-level processing. Through the above processing and in combination with the method for classification status discrimination based on tracking frame numbers, the framework of an algorithm for automatically calculating the quantity of coals flushed out was established. Subsequently, the deformable …


Coal Mining-Induced Composite Damage To Geological Bodies And Geological Guarantee Against Damage Reduction, Wang Shuangming, Sun Qiang, Hu Xin, Geng Jishi, Hou Enke, Wang Shengquan, Zhou Shutao, Shi Qingmin, Yuan Shihao, Chen Kai, Song Shijie Jan 2025

Coal Mining-Induced Composite Damage To Geological Bodies And Geological Guarantee Against Damage Reduction, Wang Shuangming, Sun Qiang, Hu Xin, Geng Jishi, Hou Enke, Wang Shengquan, Zhou Shutao, Shi Qingmin, Yuan Shihao, Chen Kai, Song Shijie

Coal Geology & Exploration

Objective and Background Coals have long served as a predominant energy source in China. With an increase in mining scale and intensity in recent years, the correlations between rocks, soils, hydrosphere, and ecological environment in coal mining areas have been strengthened. Given this, there is an urgent need to, from the perspective of Earth system science, understand the coupling relationships and chain characteristics among factors including the movement and deformations of surrounding rocks, rock bursts, coal and gas outbursts, water inrushes, ground subsidence, water and soil erosion, and damage to ecological environments, aiming to achieve safe, green coal mining. Methods …


Impacts Of Coal Fracture Roughness And Aperture On The Seepage Of Injected Water: An Experimental Study, Wang Gang, Chen Xuechang, Chen Hao, Long Qingming, Liu Yixin Jan 2025

Impacts Of Coal Fracture Roughness And Aperture On The Seepage Of Injected Water: An Experimental Study, Wang Gang, Chen Xuechang, Chen Hao, Long Qingming, Liu Yixin

Coal Geology & Exploration

Objective Water injection into coal seams is recognized as a critical technical measure for dust removal and the prevention and control of coal and gas outbursts and rock bursts in coal mines. The effectiveness of this measure is significantly influenced by the morphological characteristics of fractures, such as their roughness and aperture. Methods This study prepared coal samples containing fractures with different roughness and apertures using sandpaper and polyimide tape, calculated the fracture roughness parameters accurately using a confocal laser scanning microscope (CLSM), and tested the seepage rate of fractured coal samples. Results and Conclusions The results indicate that the …


Fracture-Seepage Characteristic Zones Of The Overburden Of Extra-Thick Coal Seams: Evolutionary Patterns And Their Engineering Applications, Kong Xiangguo, Zhao Tianshuo, Lin Haifei, Zhao Pengxiang, Wang Xu, Cai Yuchu, Ji Pengfei, He Di, Li Ke, Xu Chuanyu Jan 2025

Fracture-Seepage Characteristic Zones Of The Overburden Of Extra-Thick Coal Seams: Evolutionary Patterns And Their Engineering Applications, Kong Xiangguo, Zhao Tianshuo, Lin Haifei, Zhao Pengxiang, Wang Xu, Cai Yuchu, Ji Pengfei, He Di, Li Ke, Xu Chuanyu

Coal Geology & Exploration

Objective and Methods Given that the overburden’s structure significantly influences pressure relief gas extraction, this study aims to explore the gas migration patterns of the overburden of thick coal seams during coal seam mining. To this end, this study analyzed the evolutionary patterns of the fracture morphology and seepage capacity of the overburden using physical similarity simulation experiments. Accordingly, this study investigated the mechanisms behind the evolution of fracture-seepage characteristic zones of the overburden of extra-thick coal seams and proposed a method for identifying fracture-seepage characteristic zones of the overburden. Using this method, this study conducted gas extraction along the …


A Key Technology For Synergistic Backfilling Of Coal-Based Solid Waste And High-Salinity Wastewater, Dong Shuning, Yu Shujiang, Dong Xingling, Zhang Buqin, Guo Xiaoming, Wang Xiaodong, Wang Kai, Zhu Shibin, Wu Boqiang, Liu Lei Jan 2025

A Key Technology For Synergistic Backfilling Of Coal-Based Solid Waste And High-Salinity Wastewater, Dong Shuning, Yu Shujiang, Dong Xingling, Zhang Buqin, Guo Xiaoming, Wang Xiaodong, Wang Kai, Zhu Shibin, Wu Boqiang, Liu Lei

Coal Geology & Exploration

Background and Objective Limited by locations, as well as economic and technical levels, most of the coal-based solid waste is still accumulated in the form of open-air landfills without treatment, thus occupying large quantities of land resources and causing secondary pollution to the environment. The proper treatment and reduction of high-salinity wastewater (e.g., high-salinity mine water and high-salinity water from the coal chemical industry) represent a key link in the achievement of zero liquid discharge. However, existing technologies for high-salinity wastewater treatment are generally confronted with issues such as great initial investment and high operation costs of the treatment engineering. …


Experimental Study Of The Piezoelectricity Of Middle Pleistocene Loess In The Weibei Region, China, Jing Yanlin, Liu Jie, Liu Qingying, Duan Xiaoxiao, Xie Na, Yang Dengke Jan 2025

Experimental Study Of The Piezoelectricity Of Middle Pleistocene Loess In The Weibei Region, China, Jing Yanlin, Liu Jie, Liu Qingying, Duan Xiaoxiao, Xie Na, Yang Dengke

Coal Geology & Exploration

Objective Quartz, the piezoelectric material discovered the earliest, has found widespread applications in industry, military fields, and daily life due to its piezoelectricity. The widely distributed loess worldwide is composed primarily of quartz, accounting for 37.0% to 69.9%. However, there is a lack of studies on the piezoelectricity of loess both domestically and internationally. Methods This study investigated the ${\mathrm{Q}}_2^{{\mathrm{eol}}} $ loess from the Weibei Loess Tableland in Shaanxi Province as an example to explore the piezoelectricity of loess. The piezoelectric coefficient of the loess was measured, and its piezoelectric voltage under the action of static loading and vibration was …


Deformations And Seepage-Induced Erosion Of Fractured Rocks In Fault Under Confined Settings, Sun Wenbin, Tian Dianjin, Ma Cheng, Xue Yanchao, Yang Can, Zhu Kaipeng Jan 2025

Deformations And Seepage-Induced Erosion Of Fractured Rocks In Fault Under Confined Settings, Sun Wenbin, Tian Dianjin, Ma Cheng, Xue Yanchao, Yang Can, Zhu Kaipeng

Coal Geology & Exploration

Objective Most of the mining areas in China have entered the deep mining stage. In this case, the risks of mine water inrushes increase significantly due to the complex deep hydrogeological conditions, a significant increase in the number of hidden disaster-causing factors, and the existence of faults. Methods Using a deformation-seepage experiment system for fractured rocks, this study investigated the characteristics of compressive deformations and seepage-induced erosion of fractured rocks in faults. By analyzing the impacts of particle-size distribution combinations, saturation state, and seepage pressure, on the deformation-permeability characteristics of fractured rocks under confined axial compression, this study investigated the …


Characteristics Of Cenozoic Volcanic Edifices In The Pingnan Area, Xihu Sag, Sun Naiquan, Jiang Donghui, Pan Jie, Gao Yang, Pu Renhai, Dong Xinxu Jan 2025

Characteristics Of Cenozoic Volcanic Edifices In The Pingnan Area, Xihu Sag, Sun Naiquan, Jiang Donghui, Pan Jie, Gao Yang, Pu Renhai, Dong Xinxu

Coal Geology & Exploration

Significance Igneous rocks are well-developed in the southern Pinghu slope zone, Xihu Sag, East China Sea Shelf Basin. In this zone, the increased local geotemperature caused by magmatic activity produced significant impacts on the thermal evolution of source rocks and the formation of secondary pores in sandstone reservoirs and also serves as a significant indicator of regional tectonic movements, thus holding great significance for understanding the regional geological history. Objective and Methods This study aims to determine the formation stages and distribution patterns of igneous rocks as the cap rocks in the southern Pinghu slope zone. Using previous study results …


An Intelligent Lithology Identification Method For Sandstone And Mudstone Strata And Its Applications: A Case Study Of The Jurassic Strata In The Lunnan Area, Xinjiang, China, Cai Ming, Zhou Qingwen, Yang Cong, Chen Feng, Wu Dong, Lin Wang, Zhang Chengguang, Zhang Yuanjun, Miao Yuxin Jan 2025

An Intelligent Lithology Identification Method For Sandstone And Mudstone Strata And Its Applications: A Case Study Of The Jurassic Strata In The Lunnan Area, Xinjiang, China, Cai Ming, Zhou Qingwen, Yang Cong, Chen Feng, Wu Dong, Lin Wang, Zhang Chengguang, Zhang Yuanjun, Miao Yuxin

Coal Geology & Exploration

Objective Lithology identification lays the foundation for fine-scale reservoir evaluation. However, traditional identification methods generally utilize the interactive relationships between only 2‒3 logging parameters, suffering from low utilization rates of logging information and low identification accuracy for strata with small differences in logging responses. This seriously restricts the effects of old well reexamination. The efficient, intelligent CatBoost classification algorithm can fully mine the correlations between multi-source logging information and lithology. Methods This study investigated the Jurassic sandstone and mudstone reservoirs in the Lunnan area, Xinjiang, China. Using five logging parameters determined through sensitivity analysis, i.e., natural gamma-ray value, spontaneous potential, …