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- Numerical simulation (87)
- Coalbed methane (47)
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- Fractal dimension (11)
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- Intelligent mining (11)
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Articles 361 - 390 of 1799
Full-Text Articles in Engineering
Impacts Of The Hydrochemical Characteristics Of Coal Seam Water On The Structures And Metabolic Functions Of Microbial Communities, Wang Gaohao, Duan Shengjie, Wang Bei, Niu Guobin, Liang Yongping, Yu Feilong, Ma Kai, Zhao Weizhong
Impacts Of The Hydrochemical Characteristics Of Coal Seam Water On The Structures And Metabolic Functions Of Microbial Communities, Wang Gaohao, Duan Shengjie, Wang Bei, Niu Guobin, Liang Yongping, Yu Feilong, Ma Kai, Zhao Weizhong
Coal Geology & Exploration
Background The core of coalbed methane (CBM) bioengineering is to inject bio-fracturing fluids rich in efficient methanogenic bacteria into coal reservoirs to promote the conversion of coals to methane. However, the relationships of the hydrochemical characteristics of coal seam water with the structures and metabolic functions of microbial communities remain unclear. Methods This study investigated coal seam water from 12 typical mining areas in Ningxia. Based on microbial classification and sequencing, as well as statistical analysis, this study explored the relationships of pH, anions, cations, and chemical oxygen demand (COD) of coal seam water with the structures and metabolic functions …
Construction And Application Of A Model For Drainage Via Directional Boreholes Against Water Hazards In Deep Vertical Shafts, Zhao Chunhu, Zhu Mingcheng, Ji Yadong, Wang Shidong, Zhang Wenzhong, Zhu Kaipeng, Liu Yingfeng, Shang Hongbo, Li Chaofeng, Fan Min, Li Kai
Construction And Application Of A Model For Drainage Via Directional Boreholes Against Water Hazards In Deep Vertical Shafts, Zhao Chunhu, Zhu Mingcheng, Ji Yadong, Wang Shidong, Zhang Wenzhong, Zhu Kaipeng, Liu Yingfeng, Shang Hongbo, Li Chaofeng, Fan Min, Li Kai
Coal Geology & Exploration
Background Vertical shafts are typically employed in the deep mining areas of Jurassic coalfields in western China. However, the direct exposure of extremely thick Cretaceous aquifers frequently leads to significant water inflow in shafts. Meanwhile, the continuous sand-carrying water inflow and scouring in vertical shafts pose serious safety hazards to the overall quality of shaft walls. Methods In underground water exploration and discharge boreholes, water outlets are below the floors of aquifers to be drained. This allows unpowered water discharge. In other words, water can flow out naturally. By fully leveraging this advantage, combined with the favorable condition of spatial …
Diffusion Mechanisms Of Power-Law Grouts In Water-Rich Sand Layers During Permeation Grouting, Xie Bao, Cheng Hua, Wang Xuesong, Li Mingjing, Liu Xiangyang, Han Xueyu
Diffusion Mechanisms Of Power-Law Grouts In Water-Rich Sand Layers During Permeation Grouting, Xie Bao, Cheng Hua, Wang Xuesong, Li Mingjing, Liu Xiangyang, Han Xueyu
Coal Geology & Exploration
Objective This study aims to clarify the spherical diffusion patterns of power-law grouts in water-rich sand layers during permeation grouting and their influential factors. To this end, permeation grouting experiments were conducted to gain insights into the quantitative impacts of varying grouting parameters on grout diffusion.Methods Using model experiments on spherical diffusion during permeation grouting, this study analyzed the macroscopic diffusion morphologies and microscopic infilling effects of grouts, as well as the trends of permeation and soil pressures during grouting. Then, based on the spherical diffusion equations for permeation grouting that consider multi-effect coupling, this study analyzed the factors …
A Method For Efficient Virtual-Physical Synchronization Of The Digital Twin System Of An Excavation-Supporting Robot Cluster Targeting Coal Pillars Between Mining Faces, Mao Qinghua, Sima Junlei, Ma Hongwei, Wang Chuanwei, Chen Yanzhang, Guo Wenjin, Cui Wenda, Cheng Jiashuai
A Method For Efficient Virtual-Physical Synchronization Of The Digital Twin System Of An Excavation-Supporting Robot Cluster Targeting Coal Pillars Between Mining Faces, Mao Qinghua, Sima Junlei, Ma Hongwei, Wang Chuanwei, Chen Yanzhang, Guo Wenjin, Cui Wenda, Cheng Jiashuai
Coal Geology & Exploration
Objective Virtual models for excavation-supporting robot clusters targeting coal pillars between mining faces encounter challenges like a large data size and anomalies in data transmission, which lead to poor virtual-physical synchronization. This study proposed a method for efficient virtual-physical synchronization of the digital twin (DT) system of an excavation-supporting robot cluster using 3D model lightweighting and a trajectory prediction and correction model. Methods Fit-controlling vertices were defined, and their collapse cost factor was introduced to improve the quadratic error metric (QEM) algorithm and to constrain the lightweighting process of the 3D model of an assembly while maintaining fits between components. …
An Improved Mp-Nmo Correction Method Based On Multiparameter Fitting And Its Application, Yang Xiaohui, Yu Pengfei, Zhang Jiawei
An Improved Mp-Nmo Correction Method Based On Multiparameter Fitting And Its Application, Yang Xiaohui, Yu Pengfei, Zhang Jiawei
Coal Geology & Exploration
Objective and Methods Normal moveout (NMO) correction is a core step in seismic data processing. However, the conventional NMO correction method tends to cause wavelet stretching when processing wide-angle or large-offset seismic data, leading to degraded stacking quality and distorted amplitude variation with offset (AVO) attributes. Although the matching pursuit (MP)-NMO correction method can mitigate the stretching effect, it will cause lateral discontinuity due to overlapping seismic events. Therefore, this study developed an improved MP-NMO correction method based on multiparameter fitting. Specifically, during MP decomposition, cubic polynomial fitting was applied to the amplitude, frequencies, and phases of wavelets from the …
Table Of Contents, The Editors
Research On Underground Coal Gasification From 2023 To 2024: A Systematic Review, Qin Yong, Yi Tongsheng, Wang Lingxia
Research On Underground Coal Gasification From 2023 To 2024: A Systematic Review, Qin Yong, Yi Tongsheng, Wang Lingxia
Coal Geology & Exploration
Background The industrialization of underground coal gasification (UCG) technology presents a potential solution for securing the supply of clean energy. The latest wave of exploration into UCG is currently gaining momentum. Methods This review systematically organizes domestic and international literature, expatiates the advances in research on UCG from 2023 to 2024, analyzes the primary challenges in its development, and proposes key areas for future exploration. Advances Transformative technological advancements in the development and utilization of coal energy based on UCG have been proposed. The development of an integrated, synergistic UCG – coalbed methane – carbon capture, utilization, and storage (UCG–CBM–CCUS) …
Evolutionary Pattern And A Calculation Method Of In Situ Gas Pressure Based On Pressure-Retaining Coal Cores, Gao Mingzhong, Song Jie, Cui Pengfei, Li Yongcheng, Wang Zhipeng, Zhou Xuemin, Li Ju, Hao Zongxin, Hao Haichun
Evolutionary Pattern And A Calculation Method Of In Situ Gas Pressure Based On Pressure-Retaining Coal Cores, Gao Mingzhong, Song Jie, Cui Pengfei, Li Yongcheng, Wang Zhipeng, Zhou Xuemin, Li Ju, Hao Zongxin, Hao Haichun
Coal Geology & Exploration
Objective and Methods The in situ gas pressure of coal seams represents a crucial parameter for the safe production of coal mines and the assessment of coalbed methane (CBM) resources. To overcome current limitations in determining the in situ gas pressure, such as prolonged measurement cycles and the influence of multiple parameters on the measurement results, this study conducted isothermal adsorption and volumetric expansion desorption experiments on pressure-retaining coal cores with varying moisture contents using a self-constructed experimental system for gas pressure evolution in pressure-retaining coal cores. As a result, the evolutionary pattern of gas pressure in pressure-retaining coal cores …
Key Technologies For Surface Control Of Gas Dynamic Disasters In Coal Mines And Their Application, Wang Bo, Xu Fengyin, Liu Wenge, Shao Sihua, Wang Ning, Wen Jiandong, Cheng Guoxi, Qu Zhenghui, Xie Yadong, Han Jiaye, Li Zhi, Xu Bo, Yang Weihua, Zhang Yiteng, Li Changxing
Key Technologies For Surface Control Of Gas Dynamic Disasters In Coal Mines And Their Application, Wang Bo, Xu Fengyin, Liu Wenge, Shao Sihua, Wang Ning, Wen Jiandong, Cheng Guoxi, Qu Zhenghui, Xie Yadong, Han Jiaye, Li Zhi, Xu Bo, Yang Weihua, Zhang Yiteng, Li Changxing
Coal Geology & Exploration
Objective and Significance As the coal mining depth increases, coal mining faces increasingly prominent challenges including coal and gas outbursts, rock bursts, and compound dynamic disasters. Deepening the understanding of disaster-causing mechanisms and developing diversified prevention and control technologies are significant for the safe production of coal mines. Employing the key technologies for coalbed methane (CBM) production to control gas-related dynamic disasters is an inevitable course for the safe production of coal mines. However, large-scale, suitable technology systems are yet to be developed. Methods From the perspective of the application of key technologies for surface CBM production, this study systematically …
Microseismic Monitoring And Assessment Of Segmented Hydraulic Fracturing Of Horizontal Wells In Coal Seam Roofs, Li Quangui, Peng Shuyue, Liang Yunpei, Li Wenxi, Qian Yanan, Cheng Chunhui, Yu Changjun, Zhan Jinfei
Microseismic Monitoring And Assessment Of Segmented Hydraulic Fracturing Of Horizontal Wells In Coal Seam Roofs, Li Quangui, Peng Shuyue, Liang Yunpei, Li Wenxi, Qian Yanan, Cheng Chunhui, Yu Changjun, Zhan Jinfei
Coal Geology & Exploration
Background Microseismic monitoring, a non-destructive monitoring technique, has been extensively applied in the hydraulic fracturing performance assessment of coal seams. However, little attention is paid to the vertical wave velocity gradients in media in the same layer during the construction of layered wave velocity models. This leads to limited precision of travel time calculation and microseismic source localization, thus affecting the assessment accuracy of the hydraulic fracturing of coal seams. Objective and Methods Based on the coal seam segmented hydraulic fracturing project in a mine in Anhui, this study proposes an improved velocity model based on the Universal Kriging interpolation …
Reflections And Implementation Strategies For Constructing A Standard System For Deep Coalbed Methane Exploration And Exploitation, Chen Xinjun, Liu Zengqin, Shen Baojian, Zhao Shihu, Zhang Jiaqi, Ye Jincheng
Reflections And Implementation Strategies For Constructing A Standard System For Deep Coalbed Methane Exploration And Exploitation, Chen Xinjun, Liu Zengqin, Shen Baojian, Zhao Shihu, Zhang Jiaqi, Ye Jincheng
Coal Geology & Exploration
Objective Deep coalbed methane (CBM; burial depths: > 1500 m) in China holds considerable resource potential. As a strategic clean energy, deep CBM is exhibiting increasingly high value of exploitation and utilization. This is of great practical significance for China’s energy structure transformation and the achievement of peak carbon dioxide emissions and carbon neutrality in the country. In recent years, breakthroughs have been made in deep CBM exploration in basins such as Ordos, Sichuan, and Junggar, with a single-well daily gas production exceeding 100 000 m3, marking the initial achievement of large-scale deep CBM exploitation. However, the existing standard …
Dynamic Gas Supply Mechanism And Theoretical Production Modes Of Free Gas-Rich Deep Coal Reservoirs, Chen Shida, Zhang Taiyuan, Tang Dazhen, Xu Hao, Tao Shu, Li Song, Tang Shuling
Dynamic Gas Supply Mechanism And Theoretical Production Modes Of Free Gas-Rich Deep Coal Reservoirs, Chen Shida, Zhang Taiyuan, Tang Dazhen, Xu Hao, Tao Shu, Li Song, Tang Shuling
Coal Geology & Exploration
Objective and Methods The production processes of adsorbed and free gases and the dynamic partitioning mechanism behind the production efficiency of both gas types are critical scientific issues to be addressed urgently in the exploration and production of deep coalbed methane (CBM). Based on the test and assay data of cores from exploration wells, this study systematically analyzed the theoretical production of deep CBM resources. By integrating the building of mathematical and numerical models, carbon isotope monitoring of methane, and the analysis of production curves, this study revealed the spatiotemporal evolutionary processes of production-induced pressure drop expansion, adsorbed gas desorption, …
An Experimental Study Of Ch4 Displacement By Co2 Under Varying Initial Reservoir Pressures, Xu Jiang, Jiang Shiyu, Peng Shoujian, Wang Zhonghui, Chen Jiaxuan, Niu Huiting
An Experimental Study Of Ch4 Displacement By Co2 Under Varying Initial Reservoir Pressures, Xu Jiang, Jiang Shiyu, Peng Shoujian, Wang Zhonghui, Chen Jiaxuan, Niu Huiting
Coal Geology & Exploration
Objective This study aims to reveal the evolutionary patterns of reservoir parameters during the CO2-enhanced coalbed methane (CO2-ECBM) recovery and the impact of initial reservoir pressure on CBM recovery by gas injection. Methods Based on the multi-field coupling-based physical simulation experiment system of gas injection into coal seams for production growth, this study conducted experiments of CH4 displacement by CO2 under a constant gas injection pressure of 2.0 MPa and initial reservoir pressures of 1.5 MPa, 1.0 MPa, and 0.5 MPa. Accordingly, this study explored the spatiotemporal evolutionary patterns of multiphysical field parameters such …
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
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 …
Measures And Effects Of Eco-Geological Restoration In Well No.4 In The Muli Mining Area, Qinghai Province, China, Zhao Xin, Wang Tong, Wang Weichao, Li Congcong, Li Fei, Jiang Zhikun, Li Jin
Measures And Effects Of Eco-Geological Restoration In Well No.4 In The Muli Mining Area, Qinghai Province, China, Zhao Xin, Wang Tong, Wang Weichao, Li Congcong, Li Fei, Jiang Zhikun, Li Jin
Coal Geology & Exploration
Objective The Muli mining area, located in the hinterland of the Qilian Mountains, Qinghai Province, serves as the source of the Datong River—a major tributary of the Yellow River. This area falls within the alpine permafrost region, exhibiting a sensitive, fragile ecosystem. In the early 21st century, disordered coal mining in this area has caused ecological damage. This has notably posed four challenges in the ecological restoration of well No.4 in this area: (1) high, steep, and unstable slopes of spoil heaps; (2) a large volume of water accumulating in mining pits; (3) permafrost excavation and destruction, and (4) land …
Advances In Research On Lithium In Coal-Bearing Strata And Its Isotopes, Zhang Yun, Wei Yingchun, Cao Daiyong, Li Xin, Jin Liangliang, Dong Bo, Wang Xin
Advances In Research On Lithium In Coal-Bearing Strata And Its Isotopes, Zhang Yun, Wei Yingchun, Cao Daiyong, Li Xin, Jin Liangliang, Dong Bo, Wang Xin
Coal Geology & Exploration
Significance Lithium serves as a significant strategic metal in emerging industries, and lithium isotopes have become crucial geochemical tracers due to their pronounced mass-dependent fractionation effects. Therefore, lithium minerals in coal-bearing strata have emerged as a priority in recent exploration of strategic metallic mineral resources. Investigating the isotopic composition and variation of lithium in coal-bearing strata helps reveal the sources, migration, and enrichment process of lithium while also providing a theoretical basis for lithium exploration and exploitation in coal-bearing strata. Advances This study offers a summary of advances in research on lithium in coal-bearing strata and its isotopes from three …
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
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 …
Intelligent Identification Of The Acoustic Emission Characteristics And Crack Propagation States During Of Coal Failure Based On The Nrbo-Xgboost Model, Zhang Tianjun, Cao Xinshuang, Song Shuang, He Suinan, Xue Yilun, Liu Guoying, Chen Juntao
Intelligent Identification Of The Acoustic Emission Characteristics And Crack Propagation States During Of Coal Failure Based On The Nrbo-Xgboost Model, Zhang Tianjun, Cao Xinshuang, Song Shuang, He Suinan, Xue Yilun, Liu Guoying, Chen Juntao
Coal Geology & Exploration
Objective The dynamic hazards of coals are intimately associated with the complexity and uncertainty of coal failure, while accurately identifying the propagation states of coal cracks serves as a critical approach to investigating the instability failure of coals. However, the current identification methods based on the physical quantities of acoustic emission suffer from slow speeds and low efficiency, failing to meet the demand for safe, efficient, and intelligent mining of coal mines. Methods To achieve the intelligent identification of the crack propagation states of coals, this study constructed an optimization model based on the Newton-Raphson-based optimizer (NRBO) and the eXtreme …
Effects Of Coal Seam Dip Angle On Asymmetric Load Transfer Paths In The Overburden Of Inclined Stopes, Zhu Kaipeng, Luo Shenghu, Xie Panshi, Li Zhilin, Fan Juan, Tian Chengyang, Yi Leilei, Xu Hui
Effects Of Coal Seam Dip Angle On Asymmetric Load Transfer Paths In The Overburden Of Inclined Stopes, Zhu Kaipeng, Luo Shenghu, Xie Panshi, Li Zhilin, Fan Juan, Tian Chengyang, Yi Leilei, Xu Hui
Coal Geology & Exploration
Objectives The coal seam dip angle is recognized as the root cause of far more complex load transfer paths in the overburden of inclined stopes compared to those of common coal seams. A clear understanding of the effects of the coal seam dip angle on the load transfer paths holds great significance for the stability control of surrounding rocks in inclined coal seams. Methods Based on the engineering background of a certain coal mine in Xinjiang, this study investigated the asymmetric deformations and failure of the overburden in inclined stopes using physical similar material simulation experiments, finite element numerical simulations, …
Operation Strategy Simulation Of The Heating System For Moderately Deep Geothermal Resources, Zhao Yongzhe, Zhao Baofeng, Hu Zhenyang, Gou Li, Du Dingshan, Liu Chenglu
Operation Strategy Simulation Of The Heating System For Moderately Deep Geothermal Resources, Zhao Yongzhe, Zhao Baofeng, Hu Zhenyang, Gou Li, Du Dingshan, Liu Chenglu
Coal Geology & Exploration
Background The active utilization of moderately deep geothermal resources for heating serves as a critical measure to achieve the goals of peak carbon dioxide emissions and carbon neutrality. Meanwhile, the effectiveness of the operation strategies of the heating system using these resources directly influences heating performance and significantly affects the energy consumption of the heating system. It is necessary to prevent resource waste while utilizing geothermal energy. Methods Based on a heating project using moderately deep geothermal resources in the Guanzhong Basin, Shaanxi Province, this study established a dynamic simulation model using the TRNSYS transient simulation software. Then, this study …
Fracture Activation In The Overburden And Aquiclude Stability Under The Mining Of Close-Distance Coal Seams, Cao Jian, Su Haitao, Wang Chao, Li Jianwei, Li Liang, Mao Xuwei
Fracture Activation In The Overburden And Aquiclude Stability Under The Mining Of Close-Distance Coal Seams, Cao Jian, Su Haitao, Wang Chao, Li Jianwei, Li Liang, Mao Xuwei
Coal Geology & Exploration
Background In the Jurassic coalfield of northern Shaanxi Province, the repeated mining of close-distance coal seams exacerbates the activation of fractures in the overburden. This is prone to cause aquiclude instability, leading to groundwater loss. Methods This study aims to reveal the characteristics of fractures in the overburden and the aquiclude stability in the mining of close-distance coal seams. Using a method combining measurement statistics, physical simulations using similar materials, and theoretical analysis, this study proposed categorizing primary coal-rock combinations based on the water-preserved mining of close-distance coal seams in the Jurassic coalfield of northern Shaanxi. Additionally, this study analyzed …
Inversion Of Electric Field Component EX In The Sotem Method Based On The Improved Particle Swarm Optimization Algorithm, Zhang Jifeng, Chen Changjian, Li Yuteng, You Xiran, Ma Ziben
Inversion Of Electric Field Component EX In The Sotem Method Based On The Improved Particle Swarm Optimization Algorithm, Zhang Jifeng, Chen Changjian, Li Yuteng, You Xiran, Ma Ziben
Coal Geology & Exploration
Objective The inversion of the horizontal electric field component in the grounded-source short offset transient electromagnetic (SOTEM) method using traditional algorithms is prone to fall into local extrema. To address this challenge, this study proposed an improved particle swarm optimization (PSO) algorithm that integrates the center of gravity reverse learning strategy. Methods Based on the center of gravity reverse learning strategy, the improved PSO algorithm can dynamically adjust learning factors and the value of the adaptive inertia weight, thus improving the global search capability and convergence efficiency effectively. The performance of the improved PSO algorithm was verified using the typical …
Characteristics Of Dynamic Mode Ⅱ Fracture Of Frozen Saturated Sandstones Under Varying Low Temperatures And Loading Rates, Zhao Tao, Cui Zhao, Jia Hailiang, Yang Guangyu
Characteristics Of Dynamic Mode Ⅱ Fracture Of Frozen Saturated Sandstones Under Varying Low Temperatures And Loading Rates, Zhao Tao, Cui Zhao, Jia Hailiang, Yang Guangyu
Coal Geology & Exploration
Background Investigating the mode Ⅱ fracture of frozen saturated sandstones under dynamic disturbances, including changes in their critical stress intensity factor (SIF; i.e., fracture toughness) and energy dissipation mechanisms, is crucial for the safe excavation of frozen wellbores through drilling and blasting in coal mines. Methods Using a split Hopkinson pressure bar (SHPB), this study conducted experiments on the dynamic mode Ⅱ fracture of a sandstone specimen using the short core in compression (SCC) method (also referred to as dynamic SCC experiments) under varying temperatures and loading rates. Accordingly, this study analyzed the SIF versus time curves of the frozen …
An Experimental Study On The Yield Strength Of Cement Grout For Grouting In The Limestone Area Of A Coal Seam Floor, Zou Jun, Guo Yan, Gui Herong, Wang Weimin, Chen Zhenlin, Liu Faming, Dai Yanan, Hu Yang, Chen Zengbao, Li Jun, Gao Chuan, Li Heng
An Experimental Study On The Yield Strength Of Cement Grout For Grouting In The Limestone Area Of A Coal Seam Floor, Zou Jun, Guo Yan, Gui Herong, Wang Weimin, Chen Zhenlin, Liu Faming, Dai Yanan, Hu Yang, Chen Zengbao, Li Jun, Gao Chuan, Li Heng
Coal Geology & Exploration
Objective and Methods In recent years, regional grouting through ground directional drilling has become the preferred technique for water disaster prevention and control in floor limestones in a coal mining area. In grouting engineering, the diffusion radius of cement grout, which has always received wide attention, is constrained by multiple factors including the shear yield strength (yield strength for short) and specific gravity of cement grout, along with grouting pressure. The diffusion radius in turn influences the implementation effects of on-site grouting engineering. Among its controlling factors, the yield strength of cement grout cannot be tested on site. Given this, …
Critical Technical Parameters Of Large-Diameter Multi-Stage Casing Drilling For Mine Rescue, Xu Chao, Yao Ningping, Jiang Lei, Tian Hongjie, Liu Zhi, Zhu Ning
Critical Technical Parameters Of Large-Diameter Multi-Stage Casing Drilling For Mine Rescue, Xu Chao, Yao Ningping, Jiang Lei, Tian Hongjie, Liu Zhi, Zhu Ning
Coal Geology & Exploration
Objective This study aims to meet the needs of mine rescue in cave-in accidents occurring in narrow underground spaces and to address the contradiction between equipment miniaturization and the drilling of large-diameter rescue boreholes under complex collapse conditions. Based on the goal of constructing a 60-m-long rescue passageway, this study developed a dual-power, composite drilling process based on multi-stage casing drilling technology for large-diameter horizontal rescue boreholes under complex collapse conditions. Furthermore, this study investigated the critical drilling parameters, aiming to provide a basis for the function development and parameter formulation of rescue equipment. Methods This study designed supporting three-stage …
Application Of Five Seismic Attributes In Natural Fracture Prediction For Deep Coalbed Methane Production Along The Eastern Margin Of The Ordos Basin, Tong Jiangnan, Wang Feng, Zhang Feng, Hou Wei, Li Zhongbai, Ji Liang, Jiang Yanan, Sun Wei
Application Of Five Seismic Attributes In Natural Fracture Prediction For Deep Coalbed Methane Production Along The Eastern Margin Of The Ordos Basin, Tong Jiangnan, Wang Feng, Zhang Feng, Hou Wei, Li Zhongbai, Ji Liang, Jiang Yanan, Sun Wei
Coal Geology & Exploration
Background Natural fractures serve as both the primary storage space for free gas of deep coalbed methane (CBM) and pathways for hydrocarbon migration. Furthermore, these fractures can enhance the porosity and permeability of strata under the deep, high-pressure condition, significantly amplifying the permeability of coal seams. Therefore, the fine-scale characterization of the planar distribution of natural fractures is crucial to deep CBM production.Objectives and Methods This study investigated the No.8 coal seam in the Carboniferous Benxi Formation within the Daning-Jixian block on the eastern margin of the Ordos Basin. Through offset vector tiles (OVT) domain processing of offshore 3D …
Seepage Evolution Patterns And Self-Sealing Characterization Of Mining-Induced Overburden Fractures In Ecologically Vulnerable Mining Areas, Li Jianwei, Sun Yanchao, Zhang Chuanjiu, Ta Xupeng, Cao Jian, Zhang Jian
Seepage Evolution Patterns And Self-Sealing Characterization Of Mining-Induced Overburden Fractures In Ecologically Vulnerable Mining Areas, Li Jianwei, Sun Yanchao, Zhang Chuanjiu, Ta Xupeng, Cao Jian, Zhang Jian
Coal Geology & Exploration
Objective The ecologically vulnerable areas (EVAs) in West China have been significantly affected by coal mining. In these areas, aquifers overlying goaves have been damaged under mining disturbance, being prone to cause water resource loss and desertification. Hence, it is crucial to guide the self-sealing of fractures artificially to preserve and further restore the groundwater level.Methods This study investigated mining face 22108 in the Buertai coal mine in the Inner Mongolia Autonomous Region. Based on the physical simulation experiments using similar materials, numerical calculations, and theoretical analysis, this study delved into the seepage evolution patterns of fractures in the …
Table Of Contents, The Editors
Geological Technological Innovations And Contributions In The Exploration And Development Of The Shenfu Coalfield, Fan Limin
Coal Geology & Exploration
Background The discovery and exploration of the Shenfu coalfield (i.e., a Jurassic coalfield in northern Shaanxi Province) represent the most significant achievement in China’s coal industry during the 6th Five-Year Plan of the country, marking the onset of the strategic westward shift of China’s coal industry. The complex discovery and exploration processes of the Shenfu coalfield have yielded valuable technological innovations. A summary of advances in the geological exploration and research of this coalfield will provide significant implications and references for the geologic work and green development of major coal-producing areas in West China. Advances First, research on the coal …
Mining-Induced Fault Slip: Assessment Model And Method For Determining Fault Instability Ranges, Zhao Hongbao, Zhang Bo, Zhang Chi, Ji Dongliang
Mining-Induced Fault Slip: Assessment Model And Method For Determining Fault Instability Ranges, Zhao Hongbao, Zhang Bo, Zhang Chi, Ji Dongliang
Coal Geology & Exploration
Objective Faults are highly susceptible to activation and slip instability under the influence of mining. This might trigger many disasters such as mine earthquakes, posing serious threats to mine safety. Therefore, it is necessary to analyze the mechanical mechanisms behind mining-induced fault activation and determine the ranges of mutual feedback between mining and fault activation in advance. Methods With the 213B mining face of the Xinzhi coal mine as the engineering background, this study analyzed the fault activation process induced by mining and created an elastic mechanical model for the impacts of mining on the surrounding rocks of faults. Accordingly, …