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Full-Text Articles in Earth Sciences

Design And Efficiency Assessment Of A Passive Treatment System For Acid Mine Drainage, Yan Ruiwen, Zhu Jun, Zhu Junhao, Lin Gang, Zhang Wanqiu, Jia Zenghua, Wang Wenming, Xi Furui Jul 2025

Design And Efficiency Assessment Of A Passive Treatment System For Acid Mine Drainage, Yan Ruiwen, Zhu Jun, Zhu Junhao, Lin Gang, Zhang Wanqiu, Jia Zenghua, Wang Wenming, Xi Furui

Coal Geology & Exploration

Background Acid mine drainage (AMD) refers to highly acidic, heavy metal-rich effluent generated from mining activities, potentially causing severe environmental contamination. Methods Focusing on the Lujiang alum mine in Anhui Province, this study established a systematic framework for the design and assessment of an integrated passive AMD treatment system using the Phreeqc and AMDTreat software. Based on a comprehensive analysis of the on-site hydrogeochemical characteristics (pH: 2.93‒3.06, Fe: 5.98‒42.52 mg/L, and Al: 18.87‒32.14 mg/L) and physical conditions (flow rate: 50‒96 m3/h, available area: about 50 000 m2), this study proposed a hybrid passive treatment system comprising …


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

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

Coal Geology & Exploration

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


Conversion Relationships And Three-Dimensional Storage And Utilization Modes Of Four Water Resources In An Open-Pit Mining Area, Chen Tianci, Xu Zhimin, Sun Yajun, Fang Jie, Wang Qiangmin, Xiong Xiaofeng, Zhu Yuhao, Lu Zihan, Wan Fei Jul 2025

Conversion Relationships And Three-Dimensional Storage And Utilization Modes Of Four Water Resources In An Open-Pit Mining Area, Chen Tianci, Xu Zhimin, Sun Yajun, Fang Jie, Wang Qiangmin, Xiong Xiaofeng, Zhu Yuhao, Lu Zihan, Wan Fei

Coal Geology & Exploration

Background Open-pit coal mines in China are primarily distributed in arid and semi-arid regions such as Xinjiang and Inner Mongolia. However, the contradiction between coal mining and groundwater resource conservation is increasingly prominent in these regions. Specifically, a substantial amount of mine water inflow produced during coal mining tends to lead to the further loss of groundwater resources within the influence range of a mining area. Concurrently, the failure of efficient mine water storage intensifies the regional water shortage.Methods This study investigated a typical open-pit coal mine in eastern Inner Mongolia. Using methods such as field survey and sampling, …


Advances In Key Technologies For The Management, Restoration, Development, And Utilization Of Coal Mining Subsidence Areas, Meng Zhuanghan, Wang Yutao, Tian Yanzhe Jul 2025

Advances In Key Technologies For The Management, Restoration, Development, And Utilization Of Coal Mining Subsidence Areas, Meng Zhuanghan, Wang Yutao, Tian Yanzhe

Coal Geology & Exploration

Background Coal mining subsidence areas, formed by the exploitation of coal resources, have emerged as severe challenges to the construction of ecological civilization and the sustainable development of the social economy in China. Their management, restoration, development, and utilization play a significant role in ecological security, food security, and energy transformation. Methods This study aims to address the unresolved and emerging issues in the management of coal mining subsidence areas. Based on the core concepts of management, restoration, development, and utilization, this study developed a dual-level zoning basis system combining theories and reality. Accordingly, coal mining subsidence areas in China …


Deformation And Earthquake Potential On The North America - Caribbean - Cocos Triple Junction In Guatemala, Jeremy Maurer, Andreas Eckert, Qiaoqi Sun, Jonathan Obrist-Farner Jul 2025

Deformation And Earthquake Potential On The North America - Caribbean - Cocos Triple Junction In Guatemala, Jeremy Maurer, Andreas Eckert, Qiaoqi Sun, Jonathan Obrist-Farner

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The triple junction between the Cocos (CO), North American (NA), and Caribbean (CA) tectonic plates in Guatemala is a region of high seismic risk and includes many large faults and historic earthquakes. Previous analyses of the tectonic system have been overly simplified, resulting in discrepancies between geologically derived and geodetic models of fault slip rate. This study leverages available geodetic, seismic, and geologic data to develop new strain rate maps and faulting models for the region. We find that locking on the regional faults matches historic reports of large earthquakes and that multiple minor fault segments are active and accommodate …


A Uas-Centered Investigation Of Vorticity Characteristics And Cold Pool Structure Across Forward And Left-Flank Boundaries In Supercells, Mark R. De Bruin Jul 2025

A Uas-Centered Investigation Of Vorticity Characteristics And Cold Pool Structure Across Forward And Left-Flank Boundaries In Supercells, Mark R. De Bruin

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Supercell internal boundaries are the locus of tornadogenesis; thus, understanding the characteristics of these boundaries, particularly in terms of vorticity, is important for identifying the role they play in tornado formation. Insight into the overall characteristics of internal boundaries and their possible role in tornadogenesis have been driven by studies reliant on numerical modeling-based experiments. Observational studies often neglect above-surface conditions or, when these observations are made, lack the spatial resolution to resolve boundary characteristics. During TORUS (Targeted Observation by Radars and UAS of Supercells) 2019 and TORUS-LItE (TORUS Left-flank Intensive Experiment) 2023, uncrewed aircraft systems (UAS) and mobile mesonets …


Retraction: A Database Of Teleseismic Shear-Wave Splitting Measurements For The Ordos Block And Adjacent Areas(Seismological Research Letters (2022), 93, 5, (2731–2739), 10.1785/0220210310), Lin Liu, Stephen S. Gao, Kelly H. Liu, Tu Xue, Yan Jia, Sanzhong Li Jul 2025

Retraction: A Database Of Teleseismic Shear-Wave Splitting Measurements For The Ordos Block And Adjacent Areas(Seismological Research Letters (2022), 93, 5, (2731–2739), 10.1785/0220210310), Lin Liu, Stephen S. Gao, Kelly H. Liu, Tu Xue, Yan Jia, Sanzhong Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

An earlier version of this article (Liu et al., 2022) included private data from the Himalayan-III program which should not have been made public. The authors acknowledge and regret their negligence during the selection of the measurements. The impacted data represent only 2.7% of the total data published in this article, and after review, the authors and the editors agree that this unintentional error has no bearing on the work's scientific conclusions. Therefore, we are retracting the impacted data and have made corrections to remove any Himalayan-III program data from the article's text, figures, and supplemental tables.


Investing Hysteresis In Floodplain Dynamics Of Lakes In The Middle St. Johns River Using Sentinel-1 Sar Imagery, Keenan Hubbard Jul 2025

Investing Hysteresis In Floodplain Dynamics Of Lakes In The Middle St. Johns River Using Sentinel-1 Sar Imagery, Keenan Hubbard

Doctoral Dissertations and Master's Theses

Floodplain dynamics are often complex, with hysteresis potentially affecting the temporal relationship between flood stage and flood extent during subsequent inundation phases. This study leverages Sentinel-1 synthetic aperture radar (SAR) imagery to map flood extent in the Middle St. Johns River Lake floodplains and examine the presence of hysteresis during flood events. SAR scenes corresponding to river gauge readings were analyzed from the rising and falling limbs of a flood hydrograph. By comparing these flood maps, we assess differences in inundated areas at equivalent water levels during each stage of the flood event. The findings aim to enhance flood monitoring …


Advances In Research On Noble Gas As Tracers Of Geofluids And Helium Enrichment, Gao Yu, Liu Quanyou, Zhu Dongya, Wu Xiaoqi, Li Pengpeng Jun 2025

Advances In Research On Noble Gas As Tracers Of Geofluids And Helium Enrichment, Gao Yu, Liu Quanyou, Zhu Dongya, Wu Xiaoqi, Li Pengpeng

Coal Geology & Exploration

Background Noble gases emerge as significant tools for tracing the sources and evolutionary processes of geofluids due to their chemical inertness and different isotopic compositions across varying reservoirs. Helium serves as a noble gas tracer and a scarce resource, and its enrichment mechanisms and exploration potential have attracted wide attention.Methods Based on a summary of the geochemical data of typical gas reservoirs, volcanic gases, and surface hot springs at home and abroad, this study analyzed the interfering factors and end-member value screening in the source apportionment of noble gases. Furthermore, it summarized the applications of noble gas isotopes in …


Current Status And Future Trends Of Seismic Prediction And Assessment Technology For Coalbed Methane Reservoirs, Wu Haibo, Zhang Pingsong, Xu Shi’Ang, Huang Yaping, Dong Shouhua, Cheng Yan, Li Donghui, Zhang Sheng, Zhang Min Jun 2025

Current Status And Future Trends Of Seismic Prediction And Assessment Technology For Coalbed Methane Reservoirs, Wu Haibo, Zhang Pingsong, Xu Shi’Ang, Huang Yaping, Dong Shouhua, Cheng Yan, Li Donghui, Zhang Sheng, Zhang Min

Coal Geology & Exploration

Background The seismic prediction and assessment technology for coalbed methane (CBM) reservoirs has undergone rapid development for over three decades, playing an indispensable role in CBM exploration. Methods This study reviews the development history and current status of core technologies within the seismic prediction and assessment technical system for CBM reservoirs, including seismic-petrophysical tests, modeling and inversion, seismic wavefield simulation, seismic amplitude versus offset (AVO) inversion and seismic attribute inversion, and integrated seismic prediction of the sweet spot areas of CBM reservoir resources and engineering. Furthermore, this study delves into the impacts and limitations of the characteristics of CBM reservoirs, …


Geochemical Nature Of The Geothermal Water From Lanzhou Basin: Implications For The Genesis Of Shallow Helium-Bearing Fluids, Tang Jianzhou, Wang Shuangming, Zhang Zhicheng, Li Ke, Li Changpeng Jun 2025

Geochemical Nature Of The Geothermal Water From Lanzhou Basin: Implications For The Genesis Of Shallow Helium-Bearing Fluids, Tang Jianzhou, Wang Shuangming, Zhang Zhicheng, Li Ke, Li Changpeng

Coal Geology & Exploration

Objective and Methods Investigations on the geochemical nature of geothermal water are vital to the comprehension of the origin of helium-rich fluids in shallow basins. To address this issue, this paper reports the results of the chemical analysis, H-O isotopes and 14C ages from geothermal water and soluble gas components from the well BY-1 in Lanzhou Basin, northeastern margin of Qinghai Tibet Plateau. Chemical analysis of geothermal water samples reveals that the chemical type of geothermal water is NaCl. The show δD value of –78‰, high δ18O value (–8.7‰), low 3H value (<0.4TU), and old 14C …


Impacts Of Metakaolin And Fly Ash On The Performance Of Cement-Based Grouting Materials In Anchoring Engineering, Cheng Zhiyuan, Yang Junpeng, Xue Wei, Wei Daidong, Wang Yimin Jun 2025

Impacts Of Metakaolin And Fly Ash On The Performance Of Cement-Based Grouting Materials In Anchoring Engineering, Cheng Zhiyuan, Yang Junpeng, Xue Wei, Wei Daidong, Wang Yimin

Coal Geology & Exploration

Objective The filling of grouting materials plays a significant role in ensuring the performance of anchoring structures. This study aims to further enhance the fluidity of grouting materials, reduce their dry shrinkage in the curing process, and ensure complete filling. This will help improve the bonding property between the anchoring body and the rock and soil mass to be reinforced. Methods Using cement as the primary material, as well as fly ash and metakaolin as admixtures, this study designed and prepared 20 groups of binary and ternary mixtures and one control group. Through tests of the fluidity, bleeding ratios, and …


Diffusion Mechanisms Of Coal-Measure Helium And Their Implications For Helium Accumulation: A Case Study Of The Taiyuan Formation, Northern Qinshui Basin, China, Ma Yong, Xin Zhiyuan, Chen Jianfa, Li Yuhong, Zhang Xiutao, Jiang Haojie, Chen Zeya Jun 2025

Diffusion Mechanisms Of Coal-Measure Helium And Their Implications For Helium Accumulation: A Case Study Of The Taiyuan Formation, Northern Qinshui Basin, China, Ma Yong, Xin Zhiyuan, Chen Jianfa, Li Yuhong, Zhang Xiutao, Jiang Haojie, Chen Zeya

Coal Geology & Exploration

Objective The global helium-rich gas reservoirs are dominated by conventional natural gas reservoirs. In recent years, helium-bearing natural gas has been discovered in the Carboniferous-Permian coal measures in the Ordos Basin and surrounding regions, revealing the resource potential of coal-measure helium. However, there is almost a total lack of studies on mechanisms underlying the diffusion and migration of coal-measure helium. This severely restricts further research on the accumulation patterns of coal-measure helium.Methods This study investigated a coal seam in the Taiyuan Formation in the northern Qinshui Basin and mudstones in the coal seam roof. Using physical diffusion experiments on …


Table Of Contents, The Editors Jun 2025

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Construction And Application Of A Tcn-Lstm-Svm-Based Time Series Prediction Model For Water Inflow In Coal Seam Roofs, Liu Xuan, Ji Yadong, Zhu Kaipeng, Zhao Chunhu, Li Kai, Li Chaofeng, Yuan Chenhan, Li Panpan, Yan Pengzhen Jun 2025

Construction And Application Of A Tcn-Lstm-Svm-Based Time Series Prediction Model For Water Inflow In Coal Seam Roofs, Liu Xuan, Ji Yadong, Zhu Kaipeng, Zhao Chunhu, Li Kai, Li Chaofeng, Yuan Chenhan, Li Panpan, Yan Pengzhen

Coal Geology & Exploration

Background The accurate prediction of mine water inflow plays a significant role in the prevention and control of water hazards and the safe and efficient production in coal mines. Methods To construct a prediction model of water inflow in mines under threat of water hazards from extremely thick sandstones aquifer in West China, this study investigated a typical mine (also referred to as the studied mine) severely affected by such water hazards in the Binchang mining area of Shaanxi Province. The correlation between the mining footage and water inflow of the mining face was selected as the characteristic variable for …


Technical Advances And Research Directions Of Borehole Geophysical Prospecting For Coal Mines, Cheng Jianyuan, Yan Yu, Li Yuteng, Wang Pan, Zhao Rui, Jiang Bici Jun 2025

Technical Advances And Research Directions Of Borehole Geophysical Prospecting For Coal Mines, Cheng Jianyuan, Yan Yu, Li Yuteng, Wang Pan, Zhao Rui, Jiang Bici

Coal Geology & Exploration

Background High-precision and long-distance exploration of geological conditions is required for coal extraction and disaster prevention in coal mines. However, traditional drilling and geophysical prospecting methods face technical bottlenecks such as insufficient exploration accuracy and limited exploration ranges. Borehole geophysical prospecting technology integrates the reliable and straightforward axial results of drilling with the high-resolution transverse results of geophysical prospecting, providing technical support for safe, efficient, and intelligent coal mining. Based on the construction spaces, this study categorizes borehole geophysical prospecting technology into four types: i.e., intra-borehole, inter-borehole, borehole-surface, and borehole-roadway. Furthermore, it presents the primary advances and applicable conditions of …


Implications Of Helium Accumulation Models In Helium-Rich Basins In China For The Enrichment And Exploration Of Helium In Coal Measures, Li Yunbo, Wang Chengtao, Song Dangyu, Shi Xiaowei, Wang Rongqi Jun 2025

Implications Of Helium Accumulation Models In Helium-Rich Basins In China For The Enrichment And Exploration Of Helium In Coal Measures, Li Yunbo, Wang Chengtao, Song Dangyu, Shi Xiaowei, Wang Rongqi

Coal Geology & Exploration

Background Helium is a strategic resource in serious short supply in China, and intensifying its exploration is crucial to national resource security. China enjoys abundant coal measure gas and significant potential for associated helium accumulation. However, relevant research remains in its infancy. Methods Based on a summary and analysis of helium generation, migration, and accumulation theories in natural gas reservoirs, this study systematically investigated the enrichment patterns of helium in coal measures and proposed exploration targets. Results and Conclusions The insights reveal that the helium resources in China exhibit a distribution pattern of zoning in both north-south and east-west directions. …


Mechanisms Underlying Differential Helium Enrichment In Shale Gas Of Varying Structural Styles In The Southeastern Sichuan Basin, Xin Zhiyuan, Chen Jianfa, Wang Jie, Ma Yong Jun 2025

Mechanisms Underlying Differential Helium Enrichment In Shale Gas Of Varying Structural Styles In The Southeastern Sichuan Basin, Xin Zhiyuan, Chen Jianfa, Wang Jie, Ma Yong

Coal Geology & Exploration

Objective Shale gas reservoirs hold considerable helium reserves despite relatively low helium abundance, establishing them as a critical replacement for helium production growth. The southeastern Sichuan Basin exhibits diverse structural styles with varying preservation conditions, leading to an unclear understanding of the distribution characteristics and enrichment patterns of helium in shale gas. Determining the mechanisms behind the differential helium enrichment in shale gas is significant for the effective utilization of helium in shale gas.Methods Focusing on the typical shale gas reservoirs of different structural styles in the southeastern Sichuan Basin, this study explored the mechanisms underlying differential helium accumulation …


Physical Simulation Experiments On Competitive Dissolution Of Helium In Helium-Containing To Helium-Rich Gas Reservoirs, Zou Yi, Luo Qingyong, Chen Jianfa, Zou Huayao, Du Tao, Liu Xiaoqiang, Cai Xinyong, Yu Chengming, Fang Zilong Jun 2025

Physical Simulation Experiments On Competitive Dissolution Of Helium In Helium-Containing To Helium-Rich Gas Reservoirs, Zou Yi, Luo Qingyong, Chen Jianfa, Zou Huayao, Du Tao, Liu Xiaoqiang, Cai Xinyong, Yu Chengming, Fang Zilong

Coal Geology & Exploration

Background and Purpose Helium is widely applied in high-tech and scientific research fields due to its unique physicochemical properties. Formation water plays a key role in helium migration and enrichment. Typically, in the form of dissolved gas, helium is transported in pores or fractures by formation water. When helium-rich fluids migrate to shallow natural gas reservoirs, helium will experience dissolution and desorption exchange with other gases. This process is affected by formation temperature, pressure, and water salinity, as well as the competitive dissolution between helium and other gases. However, there is a lack of studies on the mechanisms underlying the …


Dominant Factors Causing Helium Deficiency In Coal-Measure Natural Gas In The Kuqa Depression, Tarim Basin, Liu Jiarun, Liu Quanyou, Li Pengpeng, Gao Yu, Lü Jiahao Jun 2025

Dominant Factors Causing Helium Deficiency In Coal-Measure Natural Gas In The Kuqa Depression, Tarim Basin, Liu Jiarun, Liu Quanyou, Li Pengpeng, Gao Yu, Lü Jiahao

Coal Geology & Exploration

Background Helium is identified as a scarce strategic resource, having found widespread applications in high-tech fields such as high-end manufacturing, aerospace, and national defense due to its stable chemical properties and low boiling point. The Kuqa Depression in the Tarim Basin is a significant natural gas production base in China. Determining the distribution characteristics and controlling factors of helium in coal-measure natural gas in the Kuqa Depression holds great significance.Methods Using two helium resource assessment methods and geological data, this study explored the dominant factors causing helium deficiency in the coal-measure natural gas in the Kuqa Depression.Results and …


Resource Potential And Extraction Technique Design For Helium In Coal Measures, Wang Lei, Tang Maoyin Jun 2025

Resource Potential And Extraction Technique Design For Helium In Coal Measures, Wang Lei, Tang Maoyin

Coal Geology & Exploration

Back ground Helium is an important strategic scarce resource. Presently, helium used in industry originates primarily from natural gas. In contrast, helium in coal measures, generally emerging as coalbed methane (CBM) with a high helium content, serves as a vital supplement to conventional helium resources. In industry, helium extraction from boil off gas (BOG) during natural gas liquefaction is recognized as an important way to obtain helium resources. However, existing studies on helium in coal measures mostly focus on the genesis, enrichment patterns, and geochemical characteristics of helium, while there is a lack of studies on its resource characteristics and …


Effectiveness Assessment And Spatial Distribution Characteristics Of Helium Source Rocks In The Shixi Block Along The Eastern Margin Of The Ordos Basin, Chang Yangmei, Liu Chao, Sun Beilei Jun 2025

Effectiveness Assessment And Spatial Distribution Characteristics Of Helium Source Rocks In The Shixi Block Along The Eastern Margin Of The Ordos Basin, Chang Yangmei, Liu Chao, Sun Beilei

Coal Geology & Exploration

Background Helium gas serves as a significant rare strategic resource. In China, helium resources are relatively scarce and dependent heavily on imports. Therefore, there is a pressing need for the exploration and exploitation of helium resources. Helium source rocks provide a material basis for the formation of helium resources. The Zijinshan pluton serves as a principal source of coal-measure helium along the eastern margin of the Ordos Basin. Previous studies reveal that helium in natural gas within the Shixi Block originates primarily from the decay of radioactive elements in the deep part of the Jianjiagou-Zijinshan plutons. However, there is a …


Backfill-Strip Mining And Co2 Mineralization Sequestration In Coal Mine Goaves: A Synergetic Method And Its Key Technologies, Zhu Mengbo, Liu Lang, Wang Shuangming, Wei Baoning, Rong Ruoyu, Zhang Wenzhong, Zhuang Dengdeng, Jia Qifeng Jun 2025

Backfill-Strip Mining And Co2 Mineralization Sequestration In Coal Mine Goaves: A Synergetic Method And Its Key Technologies, Zhu Mengbo, Liu Lang, Wang Shuangming, Wei Baoning, Rong Ruoyu, Zhang Wenzhong, Zhuang Dengdeng, Jia Qifeng

Coal Geology & Exploration

Objective Coals serve as both the cornerstone of China’s energy security and important industrial raw materials. However, their mining and utilization tend to cause ecological and environmental problems such as CO2 emissions, the generation of solid wastes, and land subsidence. This necessitates reforming coal mining methods to promote the green, low-carbon, and sustainable development of China’s coal industry.Methods Through the comparative analysis of the conditions of CO2 sequestration in goaves corresponding to the caving, room-and-pillar (also known as knife-pillar), and backfill mining methods, this study developed a synergetic method for backfill-strip mining and CO2 mineralization sequestration …


Analyzing The Permeability Enhancement Effect Of Hydraulic Slotting For Low-Permeability Coal Seams Based On A Stress-Diffusion-Seepage Coupling Model, Zhang Hongtu, Zhou Tian, Wang Dengke, Li Botao, Luo Yong, Pan Rongsheng, Tang Jiahao, Lu Weiyong Jun 2025

Analyzing The Permeability Enhancement Effect Of Hydraulic Slotting For Low-Permeability Coal Seams Based On A Stress-Diffusion-Seepage Coupling Model, Zhang Hongtu, Zhou Tian, Wang Dengke, Li Botao, Luo Yong, Pan Rongsheng, Tang Jiahao, Lu Weiyong

Coal Geology & Exploration

Objective and Methods This study aims to improve the permeability enhancement effect of coal seams for gas drainage. Targeting the soft, low-permeability coal seams with complex gas occurrence conditions in the Baiping mining area and considering the impacts of effective stress, gas migration, actual gas effects, and tortuosity, this study constructed a stress-diffusion-seepage coupling model based on the pore-fracture dual medium assumption. Using the coupling model, this study simulated the variation patterns of gas content in coal seams during gas drainage under varying gas contents and borehole spacings. Through field tests under different permeability enhancement measures and unloaded coal amounts …


Influencing Patterns Of Low-Temperature Nitrogen On The Pore Structure And Oxidation Characteristics Of Lignite, Xie Shuliang, Wang Gang, Qu Qingdong, Liu Hao, Sun Lulu Jun 2025

Influencing Patterns Of Low-Temperature Nitrogen On The Pore Structure And Oxidation Characteristics Of Lignite, Xie Shuliang, Wang Gang, Qu Qingdong, Liu Hao, Sun Lulu

Coal Geology & Exploration

Objective During fire prevention and extinguishment for mines, injecting normal-temperature nitrogen into goaves can only play an inerting role. Meanwhile, the preparation of liquid nitrogen is complicated and costly. Therefore, in the Wudong Coal Mine in Xinjiang, low-temperature gaseous nitrogen of –40 ℃ was prepared using nitrogen cooling devices and then injected into goaves to prevent the spontaneous combustion of residual coals. However, the influencing patterns of low-temperature nitrogen on the pore structures and oxidation characteristics of residual coals in goaves remain poorly understood. This tends to affect the prediction and forecast of the secondary oxidation of residual coals in …


Chemical Temporary Plugging-Based Full-Bore Reconstruction Technology For Old Wellbores For The Collaborative Production Of Tight-Sand Gas And Deep Coalbed Methane, Yang Fan, Tan Zhanglong, Hu Jiachen, An Qi, Li Yu, Yang Ruiyue, Lin Junwen, Sun Zening, Jing Meiyang Jun 2025

Chemical Temporary Plugging-Based Full-Bore Reconstruction Technology For Old Wellbores For The Collaborative Production Of Tight-Sand Gas And Deep Coalbed Methane, Yang Fan, Tan Zhanglong, Hu Jiachen, An Qi, Li Yu, Yang Ruiyue, Lin Junwen, Sun Zening, Jing Meiyang

Coal Geology & Exploration

Objective In China, the Ordos Basin boasts abundant coal-measure gas resources, holding considerable potential for resource development. As the development deepens, the proportion of depleted, stripper, and inefficient wells for tight-sand gas in coal measures has gradually decreased year by year. The collaborative production of tight-sand gas and deep coalbed methane (CBM) has emerged as a significant approach to effectively releasing production capacity.Methods To achieve the reconstruction of old wellbores and commingled production of new and old layers, this study proposed a technology of chemical temporary plugging-based full-bore reconstruction of old wellbores of tight-sand gas combined with the large-scale …


Prediction Of Geological And Engineering Integrated Sweet Spots Of Deep Coalbed Methane, Chen Zhengrong, Liu Wei, Zhu Xueshen, Tian Yongjing, Xie Xin Jun 2025

Prediction Of Geological And Engineering Integrated Sweet Spots Of Deep Coalbed Methane, Chen Zhengrong, Liu Wei, Zhu Xueshen, Tian Yongjing, Xie Xin

Coal Geology & Exploration

Objective Deep coalbed methane (CBM) has emerged as a hot topic in CBM resource development. However, deep CBM has characteristics such as great burial depths, complex stress environments, and strong reservoir heterogeneity, which seriously restrict sweet spot prediction and accurate well location deployment in its large-scale exploitation. Methods This study investigated a deep CBM field along the eastern margin of the Ordos Basin. Using sonic, density, and caliper logging, this study developed a coal structure index model for deep coals. By introducing the coal structure index based on the coal structure differences in deep coal seams and combining factors including …


The Borehol Wall Image Digital Description Method Of The Overlying Rock Structural Planes Evdution Process In Deep Mining, Wang Jinchao, Zou Junpeng, Li Shenghai, Wang Chao, Li Xiaobin Jun 2025

The Borehol Wall Image Digital Description Method Of The Overlying Rock Structural Planes Evdution Process In Deep Mining, Wang Jinchao, Zou Junpeng, Li Shenghai, Wang Chao, Li Xiaobin

Coal Geology & Exploration

Objective In China, as mineral resource mining is increasingly expanding towards the deep parts of the Earth, the safe and efficient exploitation of deep resources has become a major strategic and technological challenge at the national level to be addressed urgently. Understanding the movement patterns of mining-affected strata in deep environments will assist in improving the intelligent prevention and control of mine disasters, thereby ensuring the safe and efficient exploitation of deep resources. Methods Targeting the complex and diverse forms of the overburden’s structural planes in deep mining, as well as a lack of characterization methods tailored to the evolutionary …


A Method Integrating A Non-Stationary Random Field For Constrained Inversion Of Csamt Data, Dai Qianwei, Guo Luyao, Wu Yun, Xiong Zhexian, Duan Dan, Bao Zhonglin, Wu Hongfei, Hao Fengyun Jun 2025

A Method Integrating A Non-Stationary Random Field For Constrained Inversion Of Csamt Data, Dai Qianwei, Guo Luyao, Wu Yun, Xiong Zhexian, Duan Dan, Bao Zhonglin, Wu Hongfei, Hao Fengyun

Coal Geology & Exploration

Objective The inversion of controlled-source audio-frequency magnetotelluric (CSAMT) data remains challenging due to two key issues: computational efficiency and resolution. To tackle these two issues, especially the over-smoothing effect caused by traditional regularization methods in estimating complex geological structures, this study proposed an improved regularization inversion method to reflect the spatial distribution characteristics of subsurface physical property parameters more accurately. Methods The proposed method was developed using the method for establishing the stochastic partial differential equation (SPDE) based on the Matérn covariance function. By introducing vector fields and the shape parameters of a range ellipse, this method fully considered both …


A Visual Positioning Method For Tunnel Boring Machines In Underground Coal Mines Based On Anchor Net Features, Zhang Xuhui, Chi Yunkai, Du Yuyang, Jiang Junying, Yang Wenjuan, Zhao Youjun, Wan Jicheng, Wang Yanqun, Tian Chenhui Jun 2025

A Visual Positioning Method For Tunnel Boring Machines In Underground Coal Mines Based On Anchor Net Features, Zhang Xuhui, Chi Yunkai, Du Yuyang, Jiang Junying, Yang Wenjuan, Zhao Youjun, Wan Jicheng, Wang Yanqun, Tian Chenhui

Coal Geology & Exploration

Background Precise positioning of tunnel boring machines (TBMs) in underground coal mines plays a fundamental role in the automated and intelligent guidance and control of fully mechanized heading face. However, traditional visual positioning methods show limited application effects in underground roadways due to their narrow and enclosed spaces, insufficient illumination, and sparse textures. This study proposed a visual positioning method for TBMs in underground coal mines based on anchor net features.Methods A three-stream depthwise separable convolutional neural network (TSCR-NET) for image enhancement was employed to estimate the reflection, illumination, and noise in images individually. Through illumination adjustment while suppressing …