Earth Sciences Commons^™

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

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

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

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

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

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

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 …

Tundra Recovery Post-Fire In The Yukon-Kuskokwim Delta, Alaska, Leah K. Clayton, Kevin Schaefer, Elizabeth E. Hoy, Clayton D. Elder, Nancy H. F. French, Gerald V. Frost, Et.Al.

Michigan Tech Publications

The extent of wildfires in tundra ecosystems has dramatically increased since the turn of the 21st century due to climate change and the resulting amplified Arctic warming. We simultaneously studied the recovery of vegetation, subsurface soil moisture, and active layer thickness (ALT) post-fire in the permafrost-underlain uplands of the Yukon-Kuskokwim Delta in southwestern Alaska to understand the interaction between these factors and their potential implications. We used a space-for-time substitution methodology with 2017 Landsat 8 imagery and synthetic aperture radar products, along with 2016 field data, to analyze tundra recovery trajectories in areas burned from 1953 to 2017. We found …

Designing A Cave Air Monitoring System: Guide And Feedback From 15 Years Of Monitoring The Cussac Cave (France), Nicolas Peyraube, Jessica D. Villanueva, Fabien Naessens, Roland Lastennet, Sylvain Mateo, Alain Denis

International Journal of Speleology

Understanding the cave’s ventilation system is important for determining how the cavity interacts with external airflow. This requires a well-designed monitoring system. This article addresses these key aspects: how to build a monitoring system for cave air parameters and how to assess the ventilation of a cave. We proposed a flowchart to help address the issues in: 1) the modularity of a monitoring system, 2) the use of “homemade device” or “ready to use device”, 3) the frequency of measure and its effect on the electrical consumption, 4) the duration of the survey, and 5) the accessibility of the recorded …

Meeting Carbon Dioxide Removal Demand In 2030: The Potential Of Macroalgae Cultivation And Harvest, Lotta Siebert, Jiajun Wu, Lena-Katharina Bednarz, David Keller, Felix Meier, Christine Merk, Sonja Peterson, Wilfried Rickels

Journal of Ocean and Coastal Economics

A growing number of countries have announced net-zero and net-negative emissions targets, but only a few countries provide incentives for carbon dioxide removal (CDR). We derive estimates of countries' hypothetical demand for CDR in 2030 based on their emissions reduction targets under the Paris Agreement. The aggregated average global demand for CDR in the compliance year 2030 is 1064 MtCO₂, 353 MtCO₂, and 124 MtCO₂ for the low, medium, and high-cost CDR scenarios, respectively. This demand comes exclusively from countries and regions with relatively high GDP per capita, relatively high abatement costs and a limited …

Production Of Alinite-Chlormayenite Clinker And Its Hydration Behavior With Increasing Gypsum Content, Marco Simoni, Aniruddha Baral, Zhili Ren, Tristana Y. Duvallet, Robert B. Jewell, Christiane Rößler, Theodore Hanein

Earth and Environmental Sciences Faculty Publications

An alternative low-energy alinite-chlormayenite clinker was produced and its hydration with different gypsum content was studied. The clinker was produced at 1225 ◦C using reagent-grade materials in an electric kiln with alinite, larnite, and chlormayenite content of 48, 24, and 16 wt%, respectively. The hydration kinetics of the clinker with different gypsum additions (0,10, 20, and 40 wt%) did not have a distinct induction period, and the hydration was faster than Portland cement. Alinite was in general more reactive than chlormayenite. In the presence of a limited amount of gypsum (10 and 20 wt%), alinite consumed gypsum to form ettringite …

Accurate Estimation Of Jujube Leaf Chlorophyll Content Using Optimized Spectral Indices And Machine Learning Methods Integrating Geospatial Information, Nigela Tuerxun, Sulei Naibi, Jianghua Zheng, Renjun Wang, Lei Wang, Binbin Lu, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Leaf chlorophyll content (LCC) is vital for photosynthesis and ecosystem functioning; it influences carbon, water, and energy exchanges while serving as an indicator of photosynthetic activity and nitrogen levels in precision agriculture. Hyperspectral data enable precise LCC monitoring by extracting spectral indices through optimal band combination (OBC) and predicting LCC with machine learning. However, OBC faces dimensionality issues, and machine learning models often overlook geographical influences, potentially reducing prediction accuracy. This study hypothesizes that developing spectral indices from important wavelengths and integrating geospatial data into machine learning models can address these issues and increase prediction accuracy. To test this hypothesis, …

Clay Minerals Origin And Paleoclimate Implications In Quaternary Deposits Of The Saïs Plain, Fez-Morocco, Ayman Agharabi, L. Karrat, Frank R. Ettensohn, N. Har, L. Gourari, H. Bedelean, C. Balica, C. V. Mircescu

Earth and Environmental Sciences Faculty Publications

The city of Fez in northern Morocco is situated on northeastern parts of the Saïs Plain, an alluvial basin. It is spreading southwesterly onto Pleistocene sediments consisting primarily of alluvial, channel-fill conglomerates and overbank deposits, as well as Holocene tufas. As urban develop- ment expands, human activities are increasingly eradicating these deposits, about which little is known. This study focuses on the clay-mineral composition of these Pleistocene overbank de- posits, informally known as the “Red” and “Yellow” units, as well as of the Holocene tufas. In contrast to previous research that has emphasized the industrial uses of nearby Miocene marls. …

Characterization Of Btex Species At Texas Commission On Environmental Quality (Tceq) Continuous Ambient Monitoring Station (Cams) Sites In Houston, Texas, Usa During 2018, Amit U. Raysoni, Sai Deepak Pinakana, August Luna, Esmeralda Mendez, Gabriel Ibarra-Mejia

School of Earth, Environmental, & Marine Sciences Faculty Publications

Volatile Organic Compounds (VOCs) in the atmosphere negatively impact human and environmental health. Various sources of VOCs include gasoline evaporation, solvent usage, traffic, etc. A dataset 1-year (2018) consisting of BTEX (benzene, toluene, ethylbenzene, and m, p, and o-xylenes) concentrations in Houston, Texas, was analyzed to understand the spatial trends and sources of BTEX in the region. This study assesses 24-hour data concentrations from the Continuous Ambient Monitoring Station (CAMS) operated by the TCEQ Texas Commission on Environmental Quality (TCEQ) in Houston. Spatial variations of the BTEX species across the various TCEQ CAMS sites were determined using multiple statistical analyses, …

Modelled Flooding Impacts On Lower Fish River Watershed, Sebastian Loschner

Shelby Hall Graduate Research Forum Posters

This study investigates the impacts of compound flooding in the Lower Fish River watershed, Baldwin County, Alabama, with a focus on the potential effects of sea level rise due to climate change. Coastal flooding, particularly in smaller watersheds, is a growing concern as it results from the interaction of multiple factors, including rainfall, tidal changes, and extreme weather events. Compound flooding, which involves multiple flood drivers, is expected to worsen with climate change, as increased precipitation and rising sea levels create heightened flood risks. However, existing research on compound flooding predominantly focuses on large-scale watersheds, leaving a knowledge gap in …

Detection, Characterization, And Antibiotic Resistance Profiling Of Multidrug-Resistant Bacteria Isolated From Circulating Currency In The Northeastern Region Of Bangladesh, Moshiul Alam Mishu, Ashik Imran, Akash Saha, Shahida Ferdousee, Md. Rubiath Islam, Mohammad Abdullah-Al-Shoeb, Shahidul Islam, Muhammad Abul Kalam Azad

School of Earth, Environmental, & Marine Sciences Faculty Publications

Objectives

The study aims to investigate the prevalence of multidrug resistant bacteria on paper and coin currency obtained from various occupational groups in Bangladesh and to identify the bacterial species present. The research further seeks to evaluate the antibiotic resistance patterns of the identified bacterial isolates.

Methods

84 paper currency notes and 56 coins were collected from seven different sources. Bacterial contamination was assessed using standard bacteriological and biochemical tests to identify and characterize the bacteria. Antibiotic susceptibility of the isolated strains was evaluated using an antibiogram study.

Results

A total of 368 bacterial isolates were detected across the sampled …

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

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

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

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

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

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

Coal Geology & Exploration

No abstract provided.

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

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

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

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

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

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

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 …