Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Engineering

Journal

2024

Institution
Keyword
Publication

Articles 1 - 30 of 279

Full-Text Articles in Physical Sciences and Mathematics

Nickel-Catalyzed Α-Arylation Of Α-Cyanoacetates Enabled By Electrochemistry, Zi-Meng Li, Zhang-Jian Li, Anat Milo, Ping Fang, Tian-Sheng Mei May 2024

Nickel-Catalyzed Α-Arylation Of Α-Cyanoacetates Enabled By Electrochemistry, Zi-Meng Li, Zhang-Jian Li, Anat Milo, Ping Fang, Tian-Sheng Mei

Journal of Electrochemistry

β-Amino acids have a wide range of applications in the field of pharmaceuticals. Utilizing a combination strategy of nickel catalysis and paired electrolysis, a catalytic α-arylation protocol of carbonyl compounds has been developed. This protocol affords various a-aryl-a-cyanoacetates, which can be reduced to high-value-added α-aryl-β-amino acids. The cross-coupling reaction of electron-deficient aryl bromides with a-cyanoacetates achieves the expected products with good yields and functional group compatibility under mild conditions. Excessive electron-richness in initial aryl bromides facilitates the self-coupling of desired products. DFT calculations confirm that the presence of electron-rich aryl substitutions decreases the …


Effects Of Ti Addition On The Characteristics Of Al-10zn-6mg-2si/Zro2 Composites Produced By Squeeze Casting, Qesha Diva Prameshvara, Pipin Indah Lestari, Bondan Tiara Sofyan May 2024

Effects Of Ti Addition On The Characteristics Of Al-10zn-6mg-2si/Zro2 Composites Produced By Squeeze Casting, Qesha Diva Prameshvara, Pipin Indah Lestari, Bondan Tiara Sofyan

Journal of Materials Exploration and Findings

Metal matrix composite (MMC) with 7xxx aluminum matrix is potential for ballistic applications due to the combination of strength, toughness, and light weight. Previous study successfully produced aluminum-based composites with SiC particles which were able to stop type III bullet, however cracks remained on back of the plate. Therefore, in this research, SiC was replaced by zirconia (ZrO2) due to its high fracture toughness. Ti-B grain refiner was added to further improve toughness through grain boundary strengthening mechanism. This research developed 5 vol.% ZrO2 strengthened Al-10Zn-6Mg-2Si composite with addition of Al-5Ti-1B grain refiner produced through squeeze casting …


Integration Of The Ashby Technique And Pahl-Beitz Quantitative Ranking For Railway Axle Material Selection, Helya Chafshoh Nafisah, Jaka Fajar Fatriansyah, Siti Norasmah Surip May 2024

Integration Of The Ashby Technique And Pahl-Beitz Quantitative Ranking For Railway Axle Material Selection, Helya Chafshoh Nafisah, Jaka Fajar Fatriansyah, Siti Norasmah Surip

Journal of Materials Exploration and Findings

Railway axle serves as a vital connection between the train's wheels and its body. However, cyclic loading and high speed can induce fatigue in railway axle, which potentially leads to damage human safety. Therefore, it is important to find materials that have good mechanical properties with the lowest weight and cost. In this paper, a comprehensive method using Ashby chart has been performed to select candidate materials of railway axle. The methods begin with analyzing function by determining the problem, objective function, and constraints. After that, the results obtained are ranked using Pahl and Beitz quantitative weighting method. The results …


Analysis Of The Effect Of Different Surface Preparation Methods On Corrosion Resistance And Adhesion Strength Of Astm A36 Steel Substrate With Surface Tolerant Epoxy Paint As Coating Material, Irwan Wijaya Santoso, Daffa Aqila, Rini Riastuti, Rizal Tresna Ramadhani May 2024

Analysis Of The Effect Of Different Surface Preparation Methods On Corrosion Resistance And Adhesion Strength Of Astm A36 Steel Substrate With Surface Tolerant Epoxy Paint As Coating Material, Irwan Wijaya Santoso, Daffa Aqila, Rini Riastuti, Rizal Tresna Ramadhani

Journal of Materials Exploration and Findings

In the industrial world, to extend the service life of materials, protection methods are carried out to slow down the material's corrosion rate. The protection method that is often used is the coating method. The coating method is a protection method by coating the substrate material using a coating material to prevent contact between the substrate material and the environment. In this research, the substrate material used is ASTM A36 steel and the coating material used is Surface Tolerant Epoxy paint. The independent variable used in this study lies in the surface preparation method which consists of: solvent cleaning, hand …


Effect Of Recommending Users And Opinions On The Network Connectivity And Idea Generation Process, Sriniwas Pandey, Hiroki Sayama May 2024

Effect Of Recommending Users And Opinions On The Network Connectivity And Idea Generation Process, Sriniwas Pandey, Hiroki Sayama

Northeast Journal of Complex Systems (NEJCS)

The growing reliance on online services underscores the crucial role of recommendation systems, especially on social media platforms seeking increased user engagement. This study investigates how recommendation systems influence the impact of personal behavioral traits on social network dynamics. It explores the interplay between homophily, users’ openness to novel ideas, and recommendation-driven exposure to new opinions. Additionally, the research examines the impact of recommendation systems on the diversity of newly generated ideas, shedding light on the challenges and opportunities in designing effective systems that balance the exploration of new ideas with the risk of reinforcing biases or filtering valuable, unconventional …


Bibliometric Review Of The Landscape And Thematic Structure Of Research On Sustainable Mining In Asean, 1942–2022, Nathatai Janjirawatna, Sirisuhk Rakthin, Philip Hallinger May 2024

Bibliometric Review Of The Landscape And Thematic Structure Of Research On Sustainable Mining In Asean, 1942–2022, Nathatai Janjirawatna, Sirisuhk Rakthin, Philip Hallinger

Journal of Sustainable Mining

This bibliometric review addressed the lack of consolidated information on the current state of sustainable mining in the ASEAN region. The review analyzed bibliographic data associated with 539 Scopus-indexed documents on sustainable mining in ASEAN nations published through the end of 2022. Descriptive statistics identified a great disparity in the scope of research on sustainable mining practices across the ASEAN countries. Surprisingly, a significant portion of the extant research on sustainable mining in the region has been authored by scholars from outside of ASEAN. Keyword analyses highlighted several emerging research topics including life cycle assessment, conservation of natural resources, climate …


Model Of The Effect Of Voltage On Contact Angle In An Electrolytic Cell Reaction, Aaron Essilfie May 2024

Model Of The Effect Of Voltage On Contact Angle In An Electrolytic Cell Reaction, Aaron Essilfie

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

This paper investigates the hypothesis that the contact angle at the meniscus of an electrode-electrolyte can be altered during a redox reaction through the coupled understanding of electrowetting and capillarity rise. Recent studies in electrowetting have focused on dielectric surfaces but research on contact angle at the electrode-electrolyte surface is lacking. The study employs a basic electrolytic cell. By applying principles of electrowetting and capillary rise the research aims to understand the relationship between applied voltage and contact angle, to advancements in electrochemistry and microfluidics.


An Overview Of How To Measure The Kinetic Properties Of An Anode Material For The Chlorine Evolution Reaction, Cameron Vann May 2024

An Overview Of How To Measure The Kinetic Properties Of An Anode Material For The Chlorine Evolution Reaction, Cameron Vann

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The process of generating chlorine gas using electrolysis in aqueous systems is well established. However, a new process requires chlorine to be generated at high temperatures using molten salt. This harsh environment requires a new study of anode materials for the chlorine evolution reaction. Anode materials can be compared by their kinetic parameters, the transfer coefficient α and the exchange current i0. The basic theory of these properties as they relate to the chlorine evolution reaction has been detailed and an analysis method for finding these effective parameters has been shown and demonstrated.


Model To Demonstrate Effects Of Mass Transfer And Applied Current In An Electrolytic Cell, George Ankrah May 2024

Model To Demonstrate Effects Of Mass Transfer And Applied Current In An Electrolytic Cell, George Ankrah

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

This study investigates the relationship between applied current and resulting cell potential in an electrolytic system, considering the transport of electroactive species. By applying Michael Faraday's laws of electrolysis and the Nernst-Planck equation, the behavior of electroactive species in diffusion-controlled systems with and without stirring is modeled. The plots demonstrate how stirring enhances ion transport and establishes a stable Nernst diffusion layer, affecting the kinetics of electrochemical reactions. Understanding these dynamics is crucial for optimizing electrolysis processes.


Review Of Cyclic Voltammetry Measurements For Uranium In Flinak Molten Salt, Jackson Ivory May 2024

Review Of Cyclic Voltammetry Measurements For Uranium In Flinak Molten Salt, Jackson Ivory

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The electrochemical behavior of uranium FLiNaK molten salts is explored, focusing on cyclic voltammetry (CV) as a powerful tool for redox characterization and diffusion studies. Through a comprehensive review of recent research, the study highlights the significance of CV in understanding electrode kinetics, material compatibility, and process optimization in molten salt environments. The findings underscore the potential of FLiNaK molten salt reactors in advancing nuclear energy technologies, fuel processing, and waste management strategies. Collaborative interdisciplinary efforts are emphasized to address challenges and accelerate innovation in electrochemical methods for nuclear applications.


Generative Machine Learning For Cyber Security, James Halvorsen, Dr. Assefaw Gebremedhin May 2024

Generative Machine Learning For Cyber Security, James Halvorsen, Dr. Assefaw Gebremedhin

Military Cyber Affairs

Automated approaches to cyber security based on machine learning will be necessary to combat the next generation of cyber-attacks. Current machine learning tools, however, are difficult to develop and deploy due to issues such as data availability and high false positive rates. Generative models can help solve data-related issues by creating high quality synthetic data for training and testing. Furthermore, some generative architectures are multipurpose, and when used for tasks such as intrusion detection, can outperform existing classifier models. This paper demonstrates how the future of cyber security stands to benefit from continued research on generative models.


Surface Treatments' Effects On The Capacitor's Dielectric Performance Under Electro-Thermal Stresses, Haider. M. Umran, Feipeng Wang Apr 2024

Surface Treatments' Effects On The Capacitor's Dielectric Performance Under Electro-Thermal Stresses, Haider. M. Umran, Feipeng Wang

Karbala International Journal of Modern Science

Biaxial-oriented polypropylene (BOPP) films are characterized by unfavorable aging behavior because of their poor susceptibility to high temperatures, humidity, and high electric fields. This makes them unqualified to withstand harsh operating conditions, such as in capacitor applications. This study investigates the impact of annealing BOPP samples at 100 °C for five hours after fluorination at different times (15, 30, and 60 minutes) on their electrical and mechanical performance under electro-thermal stresses. Scanning electron microscope (SEM) images confirm that there is an increase in surface roughness and the formation of a dense layer of fluorine-containing groups monotonically with fluorination time. So, …


Electrochemical Syntheses Of Aryl-Substituted Benzothiophenes And Phenanthrenes Using Benzenediazonium Salts As The Aryl Radical Precursors, Li-Yuan Lan, Yang-Ye Jiang, Raymond Daniel Little, Cheng-Chu Zeng Apr 2024

Electrochemical Syntheses Of Aryl-Substituted Benzothiophenes And Phenanthrenes Using Benzenediazonium Salts As The Aryl Radical Precursors, Li-Yuan Lan, Yang-Ye Jiang, Raymond Daniel Little, Cheng-Chu Zeng

Journal of Electrochemistry

Aryl-substituted benzothiophene and phenanthrene are important structural units in medicinal chemistry and materials science. Although extensive effort has been devoted to prepare these compounds and a variety of approaches have been developed to construct the 2-substituted benzothiophene core structure, environmental-friendly and efficient synthetic means are still desired. Based on our previous electrochemical Minisci-type arylation reaction with aryl diazonium salt as the aryl precursor, as well as the work from König’s group, herein, we described the use of paired electrolysis to achieve 2-aryl benzothiophenes and 9-aryl phenanthrenes employing benzenediazonium salts as the aryl radical precursors. Initially, 2-methylthiobenzendiazonium salt 1a and 4-methylbenzene …


Electrocatalytic Cyclopropanation Of Active Methylene Compounds, Liang-Hua Jie, Hai-Chao Xu Apr 2024

Electrocatalytic Cyclopropanation Of Active Methylene Compounds, Liang-Hua Jie, Hai-Chao Xu

Journal of Electrochemistry

The development of novel strategies to access cyclopropanes has become increasingly important due to the vital role of these three-membered ring structures in synthetic intermediates, natural products, and pharmaceuticals. Herein, we present an electrocatalytic method for the synthesis of cyclopropanes through intermolecular dehydrogenative annulation of active methylene compounds and arylalkenes. This electrochemical process requires no chemical oxidants, allowing for a speedy access to various functionalized cyclopropanes from inexpensive and readily available materials.


Electrochemical Advanced Treatment Of Desulfurization Wastewater From Coal-Fired Power Plants, Ju-Cai Wei, Juan Yi, Xu Wu Apr 2024

Electrochemical Advanced Treatment Of Desulfurization Wastewater From Coal-Fired Power Plants, Ju-Cai Wei, Juan Yi, Xu Wu

Journal of Electrochemistry

Zero-emission of desulfurization wastewater is one of the main demands for coal-fired power plants. As typical high salinity wastewater, it is hard to purify the desulfurization wastewater from coal-fired power plants through traditional physicochemical treatment or biochemical treatment, e.g., COD and Cl. A high concentration of Cl ion in desulfurization wastewater restricts wastewater reuse and zero-emission. Electrochemical technology is an attractive method for high salinity wastewater zero-emission, which provides a versatile, efficient, cost-effective, easily automatable, and clean industrial process. For advanced treatment of effluent after triple box process treatment in power plants, this paper reports an electrochemical …


Exploring The Pore Structure Of Reconstructed Soils And Its Effects On Water And Salt Transport Based On Ct Scanning, Li Huakun, Zheng Liugen, Chen Yongchun, Li Bing, Tao Pengfei, Li Hao Apr 2024

Exploring The Pore Structure Of Reconstructed Soils And Its Effects On Water And Salt Transport Based On Ct Scanning, Li Huakun, Zheng Liugen, Chen Yongchun, Li Bing, Tao Pengfei, Li Hao

Coal Geology & Exploration

Coal gangue serves as a critical material for landfilling and reclamation in the subsidence areas of coal mines. However, due to its rough textures and poor water-holding capacity, soils reconstructed using coal gangue exhibit somewhat different pore structures and water-salt transport from undisturbed soils. To explore the changes in the pore structure of the reconstructed soils and their effects on water and salt transport, this study analyzed the differences in the pore structures between four samples from undisturbed soils, the overburden, mud-gangue mixtures, and gangue using CT scanning and image analysis. Furthermore, an indoor experimental device was designed to simulate …


Laws Of Changes In The Energy Of Gas Hydrate-Bearing Coals Under Different Confining Pressures And Saturations, Zhu Wei, Gao Xia, Zhang Baoyong, Wu Qiang Apr 2024

Laws Of Changes In The Energy Of Gas Hydrate-Bearing Coals Under Different Confining Pressures And Saturations, Zhu Wei, Gao Xia, Zhang Baoyong, Wu Qiang

Coal Geology & Exploration

Gas hydration for the solidification of coal seams susceptible to outbursts is a novel technology used to prevent coal and gas outbursts by reducing gas pressure and enhancing coal strength. However, an unclear understanding of the failure characteristics and the energy dissipation law of gas hydrate-bearing coals under different confining pressures and saturations leads to the lack of a theoretical basis for the prevention of dynamic disasters such as field coal and gas outbursts in deep mines. Based on the deviatoric stress-strain curves obtained using triaxial compression tests, this study calculated and analyzed the laws of changes in energy of …


Table Of Contents, The Editors Apr 2024

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Response Mechanism Characteristics Of Mining-Induced Fault Activation, Sun Wenbin, Hao Jianbang, Dai Xianzheng, Kong Lingjun Apr 2024

Response Mechanism Characteristics Of Mining-Induced Fault Activation, Sun Wenbin, Hao Jianbang, Dai Xianzheng, Kong Lingjun

Coal Geology & Exploration

In the process of coal mining, mining-induced stress perturbation is a key factor leading to fault activation, which is a primary challenge faced by safe coal mining. Fault activation is prone to induce geological disasters such as rock bursts and floor water inrushes of coal mines. Furthermore, it poses a serious threat to mining safety. Using the Flac3D software for numerical simulations and similar material simulation experiments, this study established a model for faults’ stress-displacement responses under coal mining to analyze the mechanisms behind the evolution of fault structure zones in the process of coal mining. Key findings are …


Prediction Of Mine Water Inflow Along Mining Faces Using The Ssa-Cg-Attention Multifactor Model, Ding Yingying, Yin Shangxian, Lian Huiqing, Liu Wei, Li Qixing, Qi Rongrong, Bu Changsen, Xia Xiangxue, Li Shuqian Apr 2024

Prediction Of Mine Water Inflow Along Mining Faces Using The Ssa-Cg-Attention Multifactor Model, Ding Yingying, Yin Shangxian, Lian Huiqing, Liu Wei, Li Qixing, Qi Rongrong, Bu Changsen, Xia Xiangxue, Li Shuqian

Coal Geology & Exploration

Predicting mine water inflow plays an important role in ensuring mine safety, optimizing resource allocation, and improving work efficiency. This study aims to improve the accuracy and stability of the predicted mine water inflow. Given their strong correlations with water inflow, borehole water level and microseismic energy were chosen as multifactor characteristic variables. Using these variables, this study developed the SSA-CG-Attention multifactor prediction model for mine water inflow along mining faces. The new model extracted effective nonlinear local features of data utilizing a new network structure, which was formed by integrating a convolutional neural network (CNN) based on the time …


Three-Dimensional Forward Modeling Using The Transient Electromagnetic Method Under Complex Terrains And The Analysis Of Terrain Effects, Qu Shaobo, Zhu Jiao, Jiang Zhihai, Li Maofei, He Zhilong Apr 2024

Three-Dimensional Forward Modeling Using The Transient Electromagnetic Method Under Complex Terrains And The Analysis Of Terrain Effects, Qu Shaobo, Zhu Jiao, Jiang Zhihai, Li Maofei, He Zhilong

Coal Geology & Exploration

The ground-based transient electromagnetic method (TEM), with unique advantages, has been extensively applied for hydrogeological exploration in coal mines. However, in field exploration, complex terrains tend to cause variations in geometric shapes of transmitting sources and deviations in signals received, reducing exploration accuracy. Hence, by integrating theoretical analysis and numerical simulations with the analysis of actual terrain data, this study systematically investigated the response characteristics of electrical- and magnetic-source TEM fields under complex terrains. Using the vector finite-element electromagnetic forward modeling technique based on second-order backward Euler discretization, this study delved into the laws of influence of peak and valley …


Research On Path Planning Methods For Underground Roadheader Robots, Zhang Xuhui, Zheng Xili, Yang Wenjuan, Li Yuyang, Ma Bing, Dong Zheng, Chen Xin Apr 2024

Research On Path Planning Methods For Underground Roadheader Robots, Zhang Xuhui, Zheng Xili, Yang Wenjuan, Li Yuyang, Ma Bing, Dong Zheng, Chen Xin

Coal Geology & Exploration

In order to solve the problems of difficulty and low efficiency in the movement of robotic roadheaders under conditions of non-full-section roadways in coal mines, the characteristics of unstructured environments in coal mines and the motion characteristics of robotic roadheaders were analyzed, and a path planning method for robotic roadheaders based on deep reinforcement learning was proposed. The tunnel environment was constructed in real time using depth cameras, a virtual model for detecting roadheader-tunnel collisions was established, collision detection was performed in a virtual environment using the hierarchical bounding box method, and an obstacle avoidance strategy under the restrictions of …


Exploring The Detection Performance Of Different Array Configurations For Multi-Electrode Resistivity Method Tomography Using A 2.5d Finite Element Method, Zhao Rongchun, Lyu Yuzeng, Zhang Zhi, Wei Liuye, Pan Hongxu Apr 2024

Exploring The Detection Performance Of Different Array Configurations For Multi-Electrode Resistivity Method Tomography Using A 2.5d Finite Element Method, Zhao Rongchun, Lyu Yuzeng, Zhang Zhi, Wei Liuye, Pan Hongxu

Coal Geology & Exploration

Multi-electrode resistivity method is equipped with various electrode array configurations. Due to their different electrode arrangements, various electrode array configurations tend to exhibit significantly varying detection effects under different survey environments. Hence, to achieve satisfactory detection effects using high-resolution electrical resistivity tomography, it is necessary to explore the strategy for choosing appropriate array configurations targeting different objects in practical work. Given the high applicability of the method, its forward and inversion calculations remain a critical task. Based on the differential equations to be satisfied by the point source potential in a three-dimensional structure, this study derived the variational problem to …


Intelligent Identification Method For Overburden Three Zones Of A Goaf, Li Jianwen, Zhao Wen, Wu Zhenkun, Xu Xiaobing, Wang Qingtao, Duan Longchen Apr 2024

Intelligent Identification Method For Overburden Three Zones Of A Goaf, Li Jianwen, Zhao Wen, Wu Zhenkun, Xu Xiaobing, Wang Qingtao, Duan Longchen

Coal Geology & Exploration

In this paper, an intelligent identification method was proposed to ascertain overlying strata failure types and fracture development in the overlying strata of a goaf, and identify three zones (sagging zone, fractured zone and caving zone) quickly and accurately. This method is expected to be a basis in later development of goaf treatment plans. A coal mine goaf in Shandong Province was introduced for case study, where the Bayesian Online Changepoint Detection (BOCD) algorithm was employed to analyze the changes and response characteristics of the drilling fluid loss and drilling rate over the drilling process at the boundaries of three …


Exploring Dynamic Parameters And Tooth Structure Of Self-Propelled Borehole Repairing Drill Bits, Liu Yong, Li Yang, Wei Jianping, Yuan Yongwang, Dai Shuo, Li Linyu Apr 2024

Exploring Dynamic Parameters And Tooth Structure Of Self-Propelled Borehole Repairing Drill Bits, Liu Yong, Li Yang, Wei Jianping, Yuan Yongwang, Dai Shuo, Li Linyu

Coal Geology & Exploration

Self-propelled borehole repairing drill bits provide an effective technique for repairing long boreholes that have failed. In order to further improve the borehole repair speed and gas drainage efficiency, based on the theory of jet recoil, the relationship between the jet recoil force and nozzle parameters was analyzed, and a theoretical model was established for rotational mechanics of self-propelled borehole repairing drill bits. Subsequently, the coal-breaking processes of drill bits with different tooth structures were simulated using LS-DYNA, the failure modes in coal mass broken by cutting teeth and the rules of variation in the volume of coal broken by …


Research On Tar-Rich Coals: Progress And Prospects, Wang Shuangming, Bao Yuan, Hao Yonghui, Wang Shengquan, Shi Qingmin, Li Dan, Hu Yiliang Apr 2024

Research On Tar-Rich Coals: Progress And Prospects, Wang Shuangming, Bao Yuan, Hao Yonghui, Wang Shengquan, Shi Qingmin, Li Dan, Hu Yiliang

Coal Geology & Exploration

Tar-rich coals are a coal-based oil and gas resource that integrates the properties of coal, oil, and gas. Given China's energy endowment of abundant coal resources but limited oil and gas reserves, exploiting tar-rich coals plays a significant role in alleviating China's tight supply of oil and gas resources and achieving green development and low-carbon utilization of coals. Using tar-rich coals as the keyword, we searched the CNKI and Web of Science databases for academic articles and patents published from 1985 to the end of 2023. Based on the search results, we statistically analyzed the process and main aspects of …


Mechanism And Application Of Cross-Interface Fracturing For Permeability Enhancement Through The Roof Blasting Of Tectonic Coal Seams, Gao Kui, Wang Youwei, Qiao Guodong, Tian Yu, Fu Shigui Apr 2024

Mechanism And Application Of Cross-Interface Fracturing For Permeability Enhancement Through The Roof Blasting Of Tectonic Coal Seams, Gao Kui, Wang Youwei, Qiao Guodong, Tian Yu, Fu Shigui

Coal Geology & Exploration

Deep coal mining is challenging due to deteriorating geological conditions. After undergoing multiphase tectonic movements, primary coals have evolved into soft tectonic coal seams with low permeability and high gas content, complicating drilling in coal seams. In this case, the blasting-induced fractures are not well-developed and are prone to be re-compacted. So far, no fundamental breakthrough has been achieved in the key technology of fracturing for permeability enhancement technology through the roof blasting of tectonic coal seams. Given this, this study established test models for similar simulation tests and numerical analysis on the roof blasting of coal seams. By monitoring …


Preliminarily Exploring The Theories And Technologies For Coalbed Methane Production Using Horizontal Wells: Comparison Of Conditions For Coalbed Methane And Shale Gas Exploitation, Wang Hongyan, Duan Yaoyao, Liu Honglin, Zhao Qun, Chen Shangbin, Lu Haibing, Shi Zhensheng, Sun Qinping, Chen Zhenhong, Zhou Shangwen, Yang Mingwei, Wang Cong Apr 2024

Preliminarily Exploring The Theories And Technologies For Coalbed Methane Production Using Horizontal Wells: Comparison Of Conditions For Coalbed Methane And Shale Gas Exploitation, Wang Hongyan, Duan Yaoyao, Liu Honglin, Zhao Qun, Chen Shangbin, Lu Haibing, Shi Zhensheng, Sun Qinping, Chen Zhenhong, Zhou Shangwen, Yang Mingwei, Wang Cong

Coal Geology & Exploration

Through 30 years of unremitting explorations, coalbed methane (CBM) wells in China have gradually transitioned from vertical to horizontal wells. However, the lack of basic theories on CBM production using horizontal wells is the main challenge to current CBM development. Compared to shales, coal seams exhibit heterogeneity and a minor presence of foliations and brittle minerals, hindering the formation of volumetric fracture networks. Nevertheless, the roofs and floors of coal seams have high sealing capacities and mechanical strength, creating excellent conditions for hydraulic fracturing. Some fractures in coals are filled with calcite, rendering acidification conducive to the improvement of reservoir …


Accumulation Characteristics And Exploration Prospects Of Deep Coalbed Methane In The Longtan Formation Of The Nanchuan Block On The Southeastern Margin Of The Sichuan Basin, Guo Tao, Jin Xiaobo, Wu Didi, Xie Fei, Liu Jinxian Apr 2024

Accumulation Characteristics And Exploration Prospects Of Deep Coalbed Methane In The Longtan Formation Of The Nanchuan Block On The Southeastern Margin Of The Sichuan Basin, Guo Tao, Jin Xiaobo, Wu Didi, Xie Fei, Liu Jinxian

Coal Geology & Exploration

Vertical well Y2 in the Nanchuan bloc on the southeastern margin of the Sichuan Basin has yielded daily production of natural flowing gas of 13000 m3, signifying a strategic breakthrough in deep coalbed methane (CBM) exploration on the margin. This study aims to systematically reveal the enrichment and high-yield patterns of CBM in the Nanchuan block. Using data on the regional geology, tests, assays, and production, this study investigated the accumulation characteristic and conducted exploration potential evaluation for deep CBM in the Nanchuan block from the perspective of the quality, pore and fissure characteristics, gas content, and fracability …


Fracture Propagation Mechanism In Directional Perforation And Hydraulic Fracturing Of Coal Seam Horizontal Wells, Pang Tao, Jiang Zaibing, Hui Jiangtao, Jia Bingyi Apr 2024

Fracture Propagation Mechanism In Directional Perforation And Hydraulic Fracturing Of Coal Seam Horizontal Wells, Pang Tao, Jiang Zaibing, Hui Jiangtao, Jia Bingyi

Coal Geology & Exploration

Horizontal well perforation and fracturing in complex coal-bearing strata are key to increasing coal seam permeability and enhancing gas extraction efficiency, with the formation structure and perforation location determining fracture propagation. Considering the characteristics of formation structure and perforation locations, a fracturing geological model is established. Based on the finite element method, a numerical model is constructed to study the effects of perforation location, formation conditions, and the difference between vertical stress and horizontal stress on fracture perforation. Engineering verification is conducted, and construction suggestions are proposed. Key findings are as follows: There are three scenarios for the perforation locations: …