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- Keyword
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- Numerical simulation (89)
- Coalbed methane (47)
- Coal mine (39)
- Ordos Basin (33)
- Coalbed methane (CBM) (31)
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- Deep learning (28)
- Gas drainage (28)
- Pore structure (28)
- Deep coalbed methane (CBM) (27)
- Permeability (27)
- Deep coalbed methane (25)
- Hydraulic fracturing (23)
- Tar-rich coal (23)
- Directional drilling (21)
- Underground coal mine (20)
- Coal (17)
- Horizontal well (16)
- Qinshui Basin (16)
- Machine learning (14)
- Open-pit coal mine (14)
- Rock burst (14)
- Shale gas (13)
- Underground coal gasification (UCG) (13)
- Fracture (12)
- Mine water (12)
- Prospect (12)
- Fractal dimension (11)
- Helium (11)
- Intelligent mining (11)
- Microstructure (11)
- Publication Year
Articles 421 - 450 of 1822
Full-Text Articles in Earth Sciences
Engineering Practice Of Advance Gas Control For Crushed Soft Coal Seams Through Directional Fracturing Using A Long Borehole In The Coal Seam Roof, Jia Bingyi, Li Shugang, Chen Dongdong, Zhang Qun
Engineering Practice Of Advance Gas Control For Crushed Soft Coal Seams Through Directional Fracturing Using A Long Borehole In The Coal Seam Roof, Jia Bingyi, Li Shugang, Chen Dongdong, Zhang Qun
Coal Geology & Exploration
Objective and Methods The crushed soft coal seams susceptible to intense coal and gas outbursts exhibit high gas content and pressure. Consequently, during borehole drilling for regional gas pre-drainage in such coal seams, high blowout intensity is prone to cause gas overrun and low drilling efficiency. To accelerate its development, this study analyzed the status and adaptability of existing technologies for regional advance gas drainage and pressure relief, as well as the fracture propagation characteristics of coal seam roofs during indirect fracturing using boreholes near the roofs. Accordingly, this study proposed an advance gas drainage and pressure relief technology for …
Dynamic Evolutionary Pattern Of Fractures In Tectonically Deformed Coal-Bearing Assemblages During Loading, Zhao Pengxiang, Liu Yingying, Li Shugang, Liu Yanqun, Liu Yunchuan, Wang Laolao, Lu Weidong
Dynamic Evolutionary Pattern Of Fractures In Tectonically Deformed Coal-Bearing Assemblages During Loading, Zhao Pengxiang, Liu Yingying, Li Shugang, Liu Yanqun, Liu Yunchuan, Wang Laolao, Lu Weidong
Coal Geology & Exploration
Objective The formation and evolution of fractures in tectonically deformed coals (TDCs) exert a significant influence on the occurrence of dynamic hazards to TDC-bearding combinations under mining disturbance. However, the influence patterns remain unclear. Methods Using a NanoVoxel-3000 high-resolution inspection system for multiscale integrated geotechnical scanning and analysis, this study performed uniaxial compression and CT scanning experiments on TDC-bearing combination specimens. Moreover, this study reconstructed the mesoscopic geometric structures of the specimens using the Avizo software, obtaining three-dimensional visualization models of fractures inside the specimens. Results and Conclusions During loading of a specimen studied, fractures were generated in the TDC …
A New Quantitative Assessment Model For The Joint Roughness Of Rock Masses, Chen Shijiang, Liu Hongwei, Li Tao, Yue Hu, Liu Jiangang, Yu Jiang
A New Quantitative Assessment Model For The Joint Roughness Of Rock Masses, Chen Shijiang, Liu Hongwei, Li Tao, Yue Hu, Liu Jiangang, Yu Jiang
Coal Geology & Exploration
Objective The joint roughness of rock masses significantly affects their mechanical properties such as shear strength and permeability. Therefore, its quantitative characterization is significant for the engineering practices of jointed rock masses. Current research achievements indicate that among statistical parameters, the root mean square (RMS) of first derivatives (Z2) exhibits the strongest correlation with the joint roughness of rock masses, serving as a vital method for characterizing joint roughness. However, the characterization using this parameter is severely affected by the sampling interval (SI). Methods Based on a systematic analysis of the drawbacks of Z2 in characterizing …
Zonal Prediction Of The Heights Of Water-Conducting Fracture Zones Under Varying Overburden Types In North China-Type Coalfields, Xu Dongjing, Zhang Ruiqing, Gao Weifu, Jiang Haonan, Zhu Haifeng, Li Ye, Xia Zhicun
Zonal Prediction Of The Heights Of Water-Conducting Fracture Zones Under Varying Overburden Types In North China-Type Coalfields, Xu Dongjing, Zhang Ruiqing, Gao Weifu, Jiang Haonan, Zhu Haifeng, Li Ye, Xia Zhicun
Coal Geology & Exploration
Background The gradual increase in the exploitation depth and intensity of coal resources in the North China-type coalfields has caused problems such as overburden movement and damage, as well as fracture evolution. These hot topics have attracted considerable attention. Methods A total of 117 sets of measured data on the heights of water-conducting fracture zones in the North China-type coalfields were collected, consisting of 17 sets from hard overburden, 42 sets from moderately hard overburden, and 58 sets from soft overburden. Using these data, this study explored the effects of varying mining heights, mining depths, and lengths of the mining …
A Method For Time Difference Correction For Real-Time Seismic-While-Mining Data, Jin Dan
A Method For Time Difference Correction For Real-Time Seismic-While-Mining Data, Jin Dan
Coal Geology & Exploration
Objective Seismic-while-mining (SWM) data are usually acquired using multiple stations, each of which is equipped with multiple data acquisition traces. However, the SWM data received by these stations exhibit time differences due to the lack of GPS signals underground and the fact that current network synchronization technologies are confined by network delays underground. Given that the time synchronization accuracy directly affects the quality of data processing and imaging, the time difference correction of real-time SWM data is essential for accurate SWM detection. Methods Since current high-precision timing systems on the surface suffer from signal loss underground, this study proposed an …
Influencing Mechanisms Of Microwave Radiation Duration On The Efficiency Of Methane Adsorption In Coals, Hu Yiliang, Bao Yuan, Meng Jiahao, Chen Xueru, Shan Tuo
Influencing Mechanisms Of Microwave Radiation Duration On The Efficiency Of Methane Adsorption In Coals, Hu Yiliang, Bao Yuan, Meng Jiahao, Chen Xueru, Shan Tuo
Coal Geology & Exploration
Objective Microwave radiation duration represents a critical factor in enhancing coalbed methane (CBM) recovery using microwave-aided methods. However, the influencing mechanism of microwave radiation duration on the efficiency of methane adsorption in coal seams remains unclear. This necessitates delving into the specific effects of microwave radiation duration on the adsorption efficiency and unveiling their intrinsic constraints. Methods This study investigated the No.2 coal seam in the Huangling mining area. The coal samples were irradiated for 0‒18 min using 700 W microwaves. Using experiments and analyses including isothermal adsorption, low-temperature liquid N2 adsorption, and Fourier transform infrared spectroscopy (FTIR), this study …
Assessment Indicator System For Siting Of Geologic Co2 Sequestration In Low-Porosity And Low-Permeability Saline Aquifers: A Case Study Of The Ordos Basin, Mou Yu, Wang Haofan, Shaanxi Key Laboratory For Carbon Neutral Technology, Carbon Neutrality College (Yulin), Northwest University, Xi’An 710069, China Xuejun, Ma Jinfeng, Luo Shaocheng, Li Lin, Ding Zhao
Assessment Indicator System For Siting Of Geologic Co2 Sequestration In Low-Porosity And Low-Permeability Saline Aquifers: A Case Study Of The Ordos Basin, Mou Yu, Wang Haofan, Shaanxi Key Laboratory For Carbon Neutral Technology, Carbon Neutrality College (Yulin), Northwest University, Xi’An 710069, China Xuejun, Ma Jinfeng, Luo Shaocheng, Li Lin, Ding Zhao
Coal Geology & Exploration
Objective CO2 injection and geologic sequestration in deep saline aquifers as underground spatial resources represents an important means of achieving the targets of greenhouse gas emission reduction and carbon neutrality. Current assessments of the siting and potential for geologic CO2 sequestration in saline aquifers focus primarily on the macroscopic basin and regional scales, with the assessment indicator system scarcely accounting for the suitability of low-porosity and low-permeability strata. Methods Using data from 192 wells in the Yusheng area, Ordos Basin, this study conducted the division and correlation of intervals bearing no hydrocarbon, carried out lithologic and physical interpretations …
Optimization And Application Of Sand Bailing Technology For Coalbed Methane Horizontal Wells, Zhang Fei, Wang Yibing, Cheng Lu, Mei Wenbo, Yang Qi, Shen Wenjie, Cao Chao, Lai Peng, Liao Zhengkai, Xian Bao'an, Bi Yansen
Optimization And Application Of Sand Bailing Technology For Coalbed Methane Horizontal Wells, Zhang Fei, Wang Yibing, Cheng Lu, Mei Wenbo, Yang Qi, Shen Wenjie, Cao Chao, Lai Peng, Liao Zhengkai, Xian Bao'an, Bi Yansen
Coal Geology & Exploration
Objective and Methods Coalbed methane (CBM) horizontal wells face challenges such as sand accumulation in completion strings, pipe wall scaling, and pump sticking, leading to declined CBM production or shutdown of these wells. This severely restricts continuous, stable CBM production. Removing pulverized coals and sands from wellbores through mechanical sand bailing is recognized as an effective technique to restore and improve the CBM production of horizontal wells. To address challenges such as poor string sealing performance, low efficiency, and sand consolidation in mechanical sand bailing, this study created optimized tools including claw-shaped scraper tips, sand-breaking drill bits, eccentric flaps, and …
Application Of A Generative Adversarial Network Algorithm To Filling Blank Strips Of Fractures In Formation Microresistivity Imaging Images, Kang Zhengming, Wu Chensheng, Yang Guodong, Wu Disheng, Wang Ruifei, Yang Xiangyu, Gan Wei
Application Of A Generative Adversarial Network Algorithm To Filling Blank Strips Of Fractures In Formation Microresistivity Imaging Images, Kang Zhengming, Wu Chensheng, Yang Guodong, Wu Disheng, Wang Ruifei, Yang Xiangyu, Gan Wei
Coal Geology & Exploration
Objective Gaps between the electrodes of formation microresistivity imaging (FMI) imagers lead to blank strips in the resistivity images of borehole walls, significantly influencing the parameter assessment for fractures near borehole walls. The absence of full-borehole images renders it challenging to assess the blank strip filling quality for fractures in FMI images. Using a dataset constructed utilizing both simulated and actual data, this study proposed a generative adversarial network (GAN)-based method for filling the blank strips of fractures in FMI images. Methods First, the resistivity logging responses of a fractured formation were simulated using the 3D finite element method. Actual …
An Edge Awareness-Enhanced Visual Slam Method For Underground Coal Mines, Mu Qi, Liang Xin, Guo Yuanjie, Wang Yuhao, Li Zhanli
An Edge Awareness-Enhanced Visual Slam Method For Underground Coal Mines, Mu Qi, Liang Xin, Guo Yuanjie, Wang Yuhao, Li Zhanli
Coal Geology & Exploration
Objective Underground coal mines commonly exhibit low illuminance, weak textures, and structuralization-induced feature degradation. These scenes lead to challenges of insufficient effective features and high mismatch rates to the visual simultaneous localization and mapping (SLAM) system, severely compromising its localization accuracy and robustness. Methods This study proposed an edge awareness-enhanced visual SLAM method. First, an edge-awareness constrained low-illuminance image enhancement module was developed. Specifically, images with clear textures and uniform illumination were obtained using the Retinex algorithm optimized using an adaptive gradient-domain guided filter. This significantly improved feature extraction performance under low and uneven lighting conditions. Second, an edge awareness-enhanced …
Relationship Between Continental Chemical Weathering Trends In The North China Basin And The High-Latitude Glacial Cycles From The Late Carboniferous To The Early Permian, Ling Ziyu, Yang Minfang, Wang Lei, Wang Ye, Zhang Peixin, Liu Haoqing, Shao Longyi, Lu Jing
Relationship Between Continental Chemical Weathering Trends In The North China Basin And The High-Latitude Glacial Cycles From The Late Carboniferous To The Early Permian, Ling Ziyu, Yang Minfang, Wang Lei, Wang Ye, Zhang Peixin, Liu Haoqing, Shao Longyi, Lu Jing
Coal Geology & Exploration
Objective and Methods The Late Paleozoic Ice Age (LPIA; ca. 360‒254 Ma), the only period recording the transition from icehouse to greenhouse conditions throughout the geological history, can provide a deep-time perspective for glacier-environment-climate coevolution and future climate change. To gain a deep understanding of the potential relationship between the continental chemical weathering trends in low-latitude regions and the glacial cycles in the high-latitude Gondwana region from the Late Carboniferous to the Early Permian, this study investigated the mudstones of the Benxi-Taiyuan formations, Liujiang coalfield, North China Basin. Using multiple chemical weathering indices such as chemical index of alteration (CIA), …
Anisotropy In Non-Darcy Flow In Individual Rough-Walled Rock Fractures, Zhu Yinbin, Liao Zhen, Li Changdong, Liu Hongbin, Jiang Xihui
Anisotropy In Non-Darcy Flow In Individual Rough-Walled Rock Fractures, Zhu Yinbin, Liao Zhen, Li Changdong, Liu Hongbin, Jiang Xihui
Coal Geology & Exploration
Objective Investigating the flow behavior of fluids in individual rough-walled rock fractures is fundamental for fully understanding the seepage characteristics of fluids in rock fracture networks. Methods Rock fractures were artificially synthesized based on the fractal theory, and numerical simulations of seepage along these fractures were performed using the COMSOL Multiphysics software. Then, fracture specimens with the same geometric characteristics as numerical models of fractures were prepared using 3D printing technology. In combination with the self-designed equipment for seepage experiments, this study conducted seepage experiments on these fracture specimens under different injection flow rates to investigate the impacts of varying …
Distributed Optical Fiber Acoustic Sensing-Based Optimization Of Microseismic Source Localization In The Hydraulic Fracturing For Coalbed Methane Production, Hua Hao, Cheng Bingjie, Xu Tianji, Yan Zhenqian, Gao Bo, He Cheng
Distributed Optical Fiber Acoustic Sensing-Based Optimization Of Microseismic Source Localization In The Hydraulic Fracturing For Coalbed Methane Production, Hua Hao, Cheng Bingjie, Xu Tianji, Yan Zhenqian, Gao Bo, He Cheng
Coal Geology & Exploration
Objective To achieve safe and efficient hydraulic fracturing, it is necessary to conduct timely and accurate microseismic monitoring in the reservoir stimulation process. The purpose is to analyze and assess the fracturing effects. Methods Using a permanently deployed fiber-optic cable outside the casing of a coalbed methane (CBM) well, this study employed distributed optical fiber acoustic sensing (DAS)for full-borehole, wide-azimuth, and high-density real-time monitoring of microseismic events induced by the hydraulic fracturing of coal seams. Furthermore, this study proposed a novel method for localizing microseismic sources based on information about wave travel time and a source-constrained mapping algorithm. First, effective …
A Model Predictive Control Method For Directional Borehole Trajectories In Underground Coal Mines, Li Hao, Yao Ningping, Lu Chengda, Zhang Jinbao, Wei Hongchao, Wu Jiajun, Li Jinyu
A Model Predictive Control Method For Directional Borehole Trajectories In Underground Coal Mines, Li Hao, Yao Ningping, Lu Chengda, Zhang Jinbao, Wei Hongchao, Wu Jiajun, Li Jinyu
Coal Geology & Exploration
Objective It is challenging to control the borehole trajectories during directional drilling in complex strata in underground coal mines, resulting in significant deviations from the designed trajectories. Given this, this study proposed a method for tracking and controlling directional borehole trajectories based on model predictive control (MPC). Methods Focusing on the directional drilling process conducted using a screw drill, this study investigated the movement patterns of the directional screw drill by analyzing the characteristics of directional drilling in complex strata in underground coal mines. Based on the kinematic theory, this study developed a borehole trajectory extension model for sliding directional …
Analyzing In-Situ Stress Response Characteristics Of Coals Based On Optimized Measurement-While-Drilling Parameters, Zhang Kun, Wang Ke, Ren Jianxi, Feng Shangxin, Chang Pengbo, Zhao Yutao, Miao Yanping, Hu Jian
Analyzing In-Situ Stress Response Characteristics Of Coals Based On Optimized Measurement-While-Drilling Parameters, Zhang Kun, Wang Ke, Ren Jianxi, Feng Shangxin, Chang Pengbo, Zhao Yutao, Miao Yanping, Hu Jian
Coal Geology & Exploration
Background The spatial distribution of stress in coals in underground coal mines is a significant factor influencing the safe production of mines and the optimization of mining processes. The quantitative, advanced prediction of in-situ stress in coals is significant for the precise regulation of the underground stress field and the classification of areas with rock burst risks. Methods Using the self-developed monitoring-while-drilling system, this study conducted indoor coal drilling experiments under different drilling conditions and explored the laws of effects of drilling conditions on drilling parameters (e.g., torque and drilling displacement) under varying stresses. Furthermore, this study developed a method …
Design And Simulations Of A Balancing Device With A Hydraulic Circuit For A Fully Hydraulic Top Drive Drilling System For A Drilling Rig Capable Of 10 000-M-Deep Drilling, Luo Chaochun, Wang Qingyan, Fan Liming, Li Haoxuan, Zhong Weiling, Guo Naiming
Design And Simulations Of A Balancing Device With A Hydraulic Circuit For A Fully Hydraulic Top Drive Drilling System For A Drilling Rig Capable Of 10 000-M-Deep Drilling, Luo Chaochun, Wang Qingyan, Fan Liming, Li Haoxuan, Zhong Weiling, Guo Naiming
Coal Geology & Exploration
Objective The balancing device for a fully hydraulic top drive drilling system (TDDS), an important part of a drilling rig capable of 10000-m-deep drilling, is designed to dynamically and accurately regulate the axial load in the screwing and unscrewing processes. This helps protect the threads of drill rod connectors from damage, thereby ensuring the stability and safety of drilling operations. Methods This study designed a balancing device with a hydraulic circuit for the SP.TD-01A fully hydraulic TDDS, aiming to achieve the balancing and bouncing functions required during the application of the TDDS. First, this study determined the structure and principal …
Table Of Contents, The Editors
Sedimentary Characteristics Of Coals In Meandering River And Braided River Facies And During Their Transitions: A Case Study The Walloon Subgroup In The F8 Block In The Surat Basin, Australia, Cui Zehong, Zhao Yibo, Li Zhihua, Li Shengli, Li Weiru
Sedimentary Characteristics Of Coals In Meandering River And Braided River Facies And During Their Transitions: A Case Study The Walloon Subgroup In The F8 Block In The Surat Basin, Australia, Cui Zehong, Zhao Yibo, Li Zhihua, Li Shengli, Li Weiru
Coal Geology & Exploration
Objective Australia is recognized as the fourth largest producer and the second largest exporter of coals in the world. The Bowen-Surat Basin is the largest coal producing basin in this country. The Surat Basin exhibits coal-bearing layers of the Middle Jurassic Walloon Subgroup. This subgroup features a sedimentary environment of fluvial facies, necessitating clarifying the differential sedimentary characteristics and patterns of coal seams in braided river and meandering river facies and during their transitions. Methods Using comprehensive geological analysis methods, as well as seismic data, logs, and core data, this study established the sedimentary pattern of the study area. Using …
Geological-Engineering Integrated Reconnaissance Survey Technology For Skylights As A Hidden Disaster-Causing Factor, Dong Mintao
Geological-Engineering Integrated Reconnaissance Survey Technology For Skylights As A Hidden Disaster-Causing Factor, Dong Mintao
Coal Geology & Exploration
Objective Skylights represent a primary hidden disaster factor in mines in the southern Yushen mining area within the Shanbei Jurassic coalfield, Shaanxi Province. Since they are hidden and difficult to detect, their distribution in the mining area remains unclear, posing pronounced safety hazards. This necessitates developing effective technical means to overcome challenges in the spatial exploration of skylights and ensure mine safety. Methods Focusing on a typical mine in the Yushen mining area as an example, this study explored the spatial distribution characteristics and types of skylights in the study area using the geological-engineering integrated reconnaissance survey technology that combines …
Characteristics And Prediction Methods Of Coal Spontaneous Combustion For Deep Coal Mining In The Ximeng Mining Area, Ma Li, Gao Wenbo, Tuo Longlong, Zhang Pengyu, Zheng Zhou, Guo Ruizhi
Characteristics And Prediction Methods Of Coal Spontaneous Combustion For Deep Coal Mining In The Ximeng Mining Area, Ma Li, Gao Wenbo, Tuo Longlong, Zhang Pengyu, Zheng Zhou, Guo Ruizhi
Coal Geology & Exploration
Objective The mining of deep coal seams in the Ximeng mining area within the Ordos Basin is subjected to complex environmental conditions like high in-situ stress, large water inflow, and severe air leakage, which lead to the encountered with elevated risks and difficult prediction of coal spontaneous combustion and posing challenges in predicting spontaneous combustion. Methods Coal samples from the Yingpanhao and Shilawusu coal mines in the Ximeng mining area were selected for temperature-programmed spontaneous combustion experiments to determine the characteristic parameters of coal spontaneous combustion under different moisture contents and sulfur mass fractions. Based on these parameters, as well …
Geological Condition Assessment And Selection Of Optimal Favorable Areas For Deep Underground Coal Gasification In The Yanchuannan Block, Li Xin, Chen Zhenlong, Guo Tao, Gao Xiaokang, Xiao Cui, Jin Xiaobo, Wu Caifang, Wang Fangfang
Geological Condition Assessment And Selection Of Optimal Favorable Areas For Deep Underground Coal Gasification In The Yanchuannan Block, Li Xin, Chen Zhenlong, Guo Tao, Gao Xiaokang, Xiao Cui, Jin Xiaobo, Wu Caifang, Wang Fangfang
Coal Geology & Exploration
Objective and Methods Geological condition assessment for underground coal gasification (UCG) allows for considerably reducing the risk of UCG projects, while scientific siting serves as a prerequisite for the success of UCG projects. To achieve the geological condition assessment for deep UCG and the selection of optimal favorable areas in the Yanchuannan block, this study quantified the indices of coal quality, coal seam occurrence, surrounding rocks, hydrogeology, and structures in the No.2 coal seam in the study area. Employing the technique for order preference by similarity to an ideal solution (TOPSIS) method, this study performed mathematical assessments and grading of …
A Method For Intelligent Information Extraction Of Coal Fractures Based On Μct And Deep Learning, Hu Zhazha, Zhang Xun, Jin Yi, Gong Linxian, Huang Wenhui, Ren Jianji, Norbert Klitzsch
A Method For Intelligent Information Extraction Of Coal Fractures Based On Μct And Deep Learning, Hu Zhazha, Zhang Xun, Jin Yi, Gong Linxian, Huang Wenhui, Ren Jianji, Norbert Klitzsch
Coal Geology & Exploration
Objective The fine-scale characterization of fractures in coal reservoirs is significant for the exploration and exploitation of coalbed methane (CBM) resources. Given that the size, orientation, and density of fractures directly affect the permeability of coal seams, the accurate information identification and extraction of fractures in coal seams plays a key role in revealing the formation and propagation mechanisms of fracture networks during reservoir volume fracturing. Conventional methods for fracture information extraction typically rely on manual labeling and feature extraction based on image processing techniques, exhibiting significantly limited accuracy and efficiency. Methods This study proposed a method for fracture information …
Theories, Technologies, And Prospects For The Utilization Of Deep Underground Storage Space, Wei Hengfei, Fang Jie, Shi Junjie, Li Qiuyuan, Yu Beibei, Chen Jing
Theories, Technologies, And Prospects For The Utilization Of Deep Underground Storage Space, Wei Hengfei, Fang Jie, Shi Junjie, Li Qiuyuan, Yu Beibei, Chen Jing
Coal Geology & Exploration
Background The world's energy utilization has shifted from high-carbon, high-polluting, non-renewable energy to low-carbon, clean, renewable energy. In this process, the utilization of low-carbon, clean energy typified by natural gas, wind power, solar energy, and hydrogen energy needs to be coupled with deep underground storage space (DUSS) to offset their regional constraints and instability. Additionally, low- and zero-carbon technologies like carbon dioxide (CO2) geological storage also rely on DUSS. Therefore, investigating the theories, technologies, and prospects of DUSS utilization under the low-carbon background will provide significant guidance for efficient DUSS utilization in China. Methods Based on the investigation …
Factors Influencing The Production Of Coalbed Methane From Deep Reservoirs, Wang Zhenzhi, Fu Xuehai, Pan Jienan, Jin Yi, Wang Haichao
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
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
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
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
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
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
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 …