Earth Sciences Commons^™

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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 …

Essential Pillars For The Post-2026 Colorado River Guidelines, Anne Castle, John Fleck, Eric Kuhn, Jack Schmidt, Kathryn Sorensen, Katherine Tara

The Traveling Wilburys of the Colorado River

The process for determining the operating rules for the Colorado River system that will take effect in 2027 is in full swing. While various alternative operating regimes have been proposed, no preferred or consensus alternative has yet emerged. As a group of experienced Colorado River colleagues without affiliation to any Basin State, Tribe, or interested stakeholder, we submit that there are fundamental principles that should form the basis of the ultimate Record of Decision defining management of the Colorado River for the future. We propose the following essential pillars for inclusion in the Post-2026 Guidelines.

Experimental Impacts Into Sloped Targets, J.L.B. Anderson, Tyler S.L. Kadrie, A.L. Miller, C.J. Cline Ii

Research & Creative Achievement Day

Asymmetric craters have been ob-served on sloped surfaces on the Moon [1] and extensively across Vesta [2] and Ceres [3]. For example, Lowell Crater (Fig. 1A) is a large crater on the surface of the Moon that has a small-er crater, Lowell H, which formed when an asteroid impacted the sloped surface of Lowell’s crater rim [1]. The topography map of Lowell H (Fig. 1B) shows the original sloped crater wall, the highly asymmetric and slumped Lowell H crater, and the debris flows that formed during its collapse.

Typically, impact cratering experiments are performed into smooth, flat-lying targets as a …

Geomorphic Monitoring Of Cedar Valley Creek: Investigating The Impact Of Restoration Projects And Stream Systems Over Time, Kyle Borske

Research & Creative Achievement Day

Streams and rivers are dynamic systems shaped by natural forces, but can be influenced by human intervention. This project focuses on Cedar Valley Creek to examine how geomorphic processes such as erosion, deposition, and sediment transport have been influenced over time by restoration efforts. By collecting data during field surveys, areas of instability will be identified and the effectiveness of the restoration project will be determined. This will give an understanding of the long term impacts of restoration projects and further insight on how to artificially maintain stream health.

Rapid Flips Between Warm And Cold Extremes In A Warming World, Sijia Wu, Ming Luo, Gabriel Ngar-Cheung Lau, Wei Zhang, Lin Wang, Zhen Liu, Lijie Lin, Yijing Wang, Erjia Ge, Jianfeng Li, Yuanchao Fan, Yimin Chen, Weilin Liao, Xiaoyu Wang, Xiaocong Xu, Zhixin Qi, Ziwei Huang, Faith Ka Shun Chan, David Yongqin Chen, Xiaoping Liu, Tao Pei

Plants, Soils, and Climate Faculty Publications

Rapid temperature flips are sudden shifts from extreme warm to cold or vice versa–both challenge humans and ecosystems by leaving a very short time to mitigate two contrasting extremes, but are yet to be understood. Here, we provide a global assessment of rapid temperature flips from 1961 to 2100. Warm-to-cold flips favorably follow wetter and cloudier conditions, while cold-to-warm flips exhibit an opposite feature. Of the global areas defined by the Intergovernmental Panel on Climate Change, over 60% have experienced more frequent, intense, and rapid flips since 1961, and this trend will expand to most areas in the future. During …

Trenching And Compost Sustain Grain Yield Increases Over Nine Years On Deep Sands But At A Cost, David J.M. Hall, Tom J. Edwards

Grain and Other Field Crops Research Articles

Context. Crops grown on deep sands on the south coast of WA are limited by soil physical and chemical properties including compaction and poor nutrition. Aims. Crops grown on deep sands on the south coast of Western Australia are limited by soil physical and chemical properties including compaction and poor nutrition. Our aim was to determine what effects deep-placed organic amendments have on soil properties and crop production in a deep sand and whether such amendments are profitable. Methods. A long-term field trial was conducted over nine years (2015–2023) to investigate soil amendments including lime (0 and …

Innovative Machine Learning, Isotopic, And Hydrogeochemical Techniques For Groundwater Analysis In Arid Landscapes In Egypt’S Eastern Desert, Saad Ahmed Mohallel, Hesham Morgan, Ali Elgendy, Surendra Maharjan, Shahryar Fazli, Wenzhao Li, Rejoice Thomas, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Groundwater serves as a lifeline in Egypt’s hyper-arid Eastern Desert, particularly for agricultural and domestic uses. However, a comprehensive understanding of groundwater origin, quality, and recharge dynamics in the region remains limited due to geological complexity, data scarcity, and the high cost of isotopic analysis. This study addresses these challenges by integrating stable isotopes (δ¹⁸O and δ²H), hydrogeochemical parameters, remote sensing, and explainable artificial intelligence (AI) to investigate groundwater dynamics and support sustainable water management strategies. A total of 34 groundwater samples were collected from three key aquifers: the Quaternary alluvium, Nubian Sandstone, and fractured Basement aquifers. Hydrochemical analyses and …

Decadal To Millennial-Scale Morphodynamic Evolution Of Microtidal Marshes, Samuel Mason Zapp

LSU Doctoral Dissertations

Tidal marshes are susceptible to rapidly converting to open water due to their low elevations within the tidal frame. A continuous supply of externally supplied mineral sediment and in situ organic material production is necessary to offset elevation losses from relative sea level rise and erosion. Complex feedbacks between hydrodynamics, the erosion, transport, and deposition of sediment, and physical modification of the landscape by the establishment of intertidal vegetation govern the spatial and temporal patterns of elevation response. This dissertation focuses on modeling how these dynamics drive marsh landscape evolution in the past, present, and into the future under changing …

Development Of Isoscapes For Hong Kong Freshwater Streams As A Basis For Ecological Studies, Hon Tim Yip

Lingnan Theses (MPhil & PhD)

Applications of isoscapes in terrestrial and marine ecosystems have grown notably as a tool for studying animal movement. However, isoscapes are rarely used in freshwater ecosystem because current iterations of isoscapes commonly model baseline distributions of bulk stable isotope analysis (SIA) data, which may be inadequate for providing the necessary resolution for fine spatial scale stream environments. This issue could potentially be addressed using compound specific stable isotope analysis, a new method that measures the isotopic composition of individual compounds to provide more comprehensive information than bulk SIA. My study focuses on δ¹³C of essential amino acids (EAA-δ …

The Effect Of Soil Conditioner And Growth Booster On The Agronomic Characters And Number Of Nodules Of Black Soybean, Tien Turmuktini, I Putu Rahmat Santoso, Lia Amalia, Nunung Sondari, Elly Roosma Ria, Yenny Muliani, Endang Kantikowati, Tualar Simarmata

Jurnal Kultivasi

Soil Conditioner & Growth Booster (SCGB) is a potion that was made to be used as a soil conditioner and plant growth promoter. SCGB is made from organic matter, biological fertilizers, soil ameliorants, and microelements. This research aims to determine the best dosage of SCGB on the agronomic characters, effective nodules, and black soybean variety ‘Detam-1’ yield. This research was conducted in the experimental field of the Faculty of Agriculture, Winaya Mukti University, Sumedang, Indonesia. This experiment used a simple randomized block design (RBD) with six treatments (0, 3, 6, 9, 12, 15 kg/ha) and repeated 4 times. The observation …

Mgrre_Geolog_Collections Weber, Harry B 1 21011286290000, Mgrre Western Michigan University

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Mgrre_Geolog_Collections Crowley, Orville 1 21037290830000, Mgrre Western Michigan University

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Mgrre_Geolog_Collections Lopez, Byrdie Et Al 1 21015284730000, Mgrre Western Michigan University

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Mgrre_Geolog_Collections Brown, Chloey 1 21049283400000, Mgrre Western Michigan University

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Mgrre_Geolog_Collections Buell, Darius & Charlotte, & Wallrich, W&R 1 21009292220000, Mgrre Western Michigan University

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