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2024

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Articles 91 - 120 of 347

Full-Text Articles in Oil, Gas, and Energy

Landslide Sensitivity Assessment Of Coal Mining Subsidence Areas Based On Information Value - Machine Learning Coupling Models, Niu Chenhao, Jiao Runcheng, Han Jianfeng, Wang Shengyu, Guo Xuefei, Liu Chang, Han Yucheng, Song Guofeng Sep 2024

Landslide Sensitivity Assessment Of Coal Mining Subsidence Areas Based On Information Value - Machine Learning Coupling Models, Niu Chenhao, Jiao Runcheng, Han Jianfeng, Wang Shengyu, Guo Xuefei, Liu Chang, Han Yucheng, Song Guofeng

Coal Geology & Exploration

Objective Due to their special geological conditions and coal mining background, coal mining subsidence areas are prone to suffer from ground cracks and subsidence, which tend to further induce geological disasters such as landslides. This makes it extremely necessary to conduct landslide sensitivity assessment of these areas using appropriate influencing factors and training models. Methods This study investigated the Xishan coal mine area in Beijing as an example to conduct landslide sensitivity assessment of coal mining subsidence areas by coupling slope units with mathematical statistical and machine learning models. With 10 influencing factors, including topographic and geomorphic factors such as …


Research And Application Of The Seismic Exploration Technique Using Reflected In-Seam Waves In Identifying Folds And Faults In Coal Seams, Wu Guoqing Sep 2024

Research And Application Of The Seismic Exploration Technique Using Reflected In-Seam Waves In Identifying Folds And Faults In Coal Seams, Wu Guoqing

Coal Geology & Exploration

Background Accurately identifying subsurface anomalies is crucial to building a geological transparency system in the transformation to intelligent coal mines. The precise exploration of fold anomalies is a challenge of underground geophysical exploration technology, holding great significance for reducing excavation costs, mining difficulties, and safety risks. Objective and Methods Previous in-seam seismic explorations reveal that folds pose significant impacts on the propagation characteristics of in-seam waves. However, conventional inversion techniques of in-seam waves are difficult to distinguish folds from faults. This study constructed numerical models for faults and folds with similar geometric shapes and equal exploration distances. Specifically, the differences …


A Method For Reconstructing Consecutively Missing Seismic Data Based On Recurrent Feature Reasoning, Li Zijuan, Chang Guangyao, Jia Yongna Sep 2024

A Method For Reconstructing Consecutively Missing Seismic Data Based On Recurrent Feature Reasoning, Li Zijuan, Chang Guangyao, Jia Yongna

Coal Geology & Exploration

Objective Due to the constraints of natural environments like rapids, rifts, and high mountains, the acquired seismic data are often challenged by consecutive missing, affecting subsequent seismic data processing and geologic analysis. Hence, it is necessary to reconstruct the missing data through interpolation. Methods This study proposed a method for reconstructing consecutively missing seismic data based on recurrent feature reasoning. First, the missing seismic data undergo partial convolution operations, in which the weight of the convolution results is adaptively adjusted based on the proportion of valid feature map data in the receptive field, avoiding invalid convolution operations on consecutively missing …


A Neural Network-Based Method For Analyzing Diffracted Wave Velocity, Tao Junhong, Zhao Jingtao, Sheng Tongjie Sep 2024

A Neural Network-Based Method For Analyzing Diffracted Wave Velocity, Tao Junhong, Zhao Jingtao, Sheng Tongjie

Coal Geology & Exploration

Background In seismic imaging, accurate velocity models are crucial for characterizing subsurface structures in a fine-scale manner. Notably, in coal mining, small-scale geological structures like faults and collapse columns are closely associated with mining accidents. These structures typically occur as diffracted waves in seismograms.Objective and Methods To effectively image these small-scale geological bodies, fine-scale velocity modeling using diffracted wave information is particularly important. Hence, this study proposed a neural network-based method for analyzing diffracted-wave velocity. First, diffracted-wave velocity spectra were generated using the gathers of diffracted waves that were separated in the common virtual source domain. Second, a gamma-ray …


Key Technology And Practice Of Deep Borehole Pneumatic Directional Drilling In Broken-Soft Coal Seam In Yangquan Mining Area, Liu Fei, Li Quanxin, Fang Jun, Liu Jianlin, Yang Weifeng, Chu Zhiwei, Zhao Jianguo, Wang Siyi Sep 2024

Key Technology And Practice Of Deep Borehole Pneumatic Directional Drilling In Broken-Soft Coal Seam In Yangquan Mining Area, Liu Fei, Li Quanxin, Fang Jun, Liu Jianlin, Yang Weifeng, Chu Zhiwei, Zhao Jianguo, Wang Siyi

Coal Geology & Exploration

Objective In response to the need for precise, proactive, and regional management of gas in the broken-soft coal seam of the Yangquan Mining Area, a technical scheme utilizing pneumatic directional drilling for pre-drainage boreholes was proposed. Methods Based on the analysis of the technical challenges in pneumatic directional drilling, a series of technologies suitable for the broken-soft coal seam in the Yangquan Mining Area were developed. These include stable operation technology for pneumatic downhole motors, precise control technology for drilling boreholes, efficient deep-hole slag discharge technology, and pneumatic milling and salvage technology. The pneumatic directional drilling equipment was optimized, and …


Emergency Response And Critical Technologies For Large-Diameter Boreholes In Mine Rescue Through Surface Drilling, Ma Tan, Zhuge Lei, Zhao Weidong Sep 2024

Emergency Response And Critical Technologies For Large-Diameter Boreholes In Mine Rescue Through Surface Drilling, Ma Tan, Zhuge Lei, Zhao Weidong

Coal Geology & Exploration

Objective Large-diameter lifesaving holes have been successfully applied multiple times in mine rescue through surface drilling. However, they show limitations in emergency response like quick dispatch and cross-regional rescue, and their technological adaptability is insufficient to cope with complex strata. Methods From the perspective of overall emergency rescue, with rescue timeliness as an indicator, this study summarized the critical technologies like response capability enhancement and borehole-forming technology for complex strata. It constructed an emergency handling process for mine rescue through surface drilling, specified the improvements in contingency plan activation, response actions, and response speeds, and established the hierarchical cross-regional rescue …


Accumulation Patterns And Exploitation And Utilization Targets Of Geothermal Resources In The Coal-Bearing Area In North China, Pang Zhonghe, Duan Zhongfeng Sep 2024

Accumulation Patterns And Exploitation And Utilization Targets Of Geothermal Resources In The Coal-Bearing Area In North China, Pang Zhonghe, Duan Zhongfeng

Coal Geology & Exploration

Objective China is a major producer and consumer of coal resources in the world. The urgent need for the transition of the coal industry necessitates the investigation of both the origin and distribution patterns of geothermal resources in the coal-bearing areas of the country. The coal-bearing area in North China, with geothermal reserves accounting for 74.7% of the whole country, stands out as one of the areas with the most abundant geothermal resources nationally. This area encompasses four major coal-bearing basins: the Bohai Bay, Ordos, Qinshui, and Southern North China, with the lithospheric thermal state gradually weakening from east to …


Convection - Heat Transfer Coupling Mechanism For Closed-Loop Heat Extraction From Hydrothermal Resources Using Horizontal Wells, Gu Feng, Li Youwu, Zhang Yue, Gao Ying, Yang Peng, Wang Anran, Cui Jingyun Sep 2024

Convection - Heat Transfer Coupling Mechanism For Closed-Loop Heat Extraction From Hydrothermal Resources Using Horizontal Wells, Gu Feng, Li Youwu, Zhang Yue, Gao Ying, Yang Peng, Wang Anran, Cui Jingyun

Coal Geology & Exploration

Objective Closed-loop heat extraction technology, which extracts geothermal energy without draining geothermal water, has emerged as a research focus in geothermal energy exploitation. However, there is a lack of studies on the impacts of convection in reservoirs on heat transfer. Methods To improve single-well heat extraction, this study proposed a technology of closed-loop heat extraction from hydrothermal reservoirs using horizontal wells. This technology aims to increase the contact area between wellbores and reservoirs while fully leveraging the convection in reservoirs. A flow and heat transfer model characterized by the coupling of horizontal wells, circulating water and reservoirs was established to …


Method Of Selecting The Optimal Variant Of Mine Closure With The Possibility Of Capturing Methane From Underground Excavations, Marian Turek, Małgorzata Magdziarczyk Sep 2024

Method Of Selecting The Optimal Variant Of Mine Closure With The Possibility Of Capturing Methane From Underground Excavations, Marian Turek, Małgorzata Magdziarczyk

Journal of Sustainable Mining

The article presents a method of selecting the optimal option for the closure of a coal mine, from which it is planned to capture the methane remaining in the goaf and deposit it for many years for its economic use. Using the example of several options for the closure of one of the mines, for which the evaluation criteria have been defined, and the weights of their relevance have been determined, it is described how to create a special algorithm for the selection of the optimal option.


Application Of Haines And Terbrugge Chart For Suitable Slope Angles – A Case Study Of Artisanal And Small-Scale Mining, Carol Mgiba, Steven Rupprecht Sep 2024

Application Of Haines And Terbrugge Chart For Suitable Slope Angles – A Case Study Of Artisanal And Small-Scale Mining, Carol Mgiba, Steven Rupprecht

Journal of Sustainable Mining

Significant hazards in Artisanal and small-scale mining (ASM) are rock failure and slope collapse caused by overly steep pit walls, poor mine design and water pressure. There is a lack of expertise and capital in ASM. Providing a simple and cost-effective slope stability analysis and designing systems that can mitigate the risk of slope collapse is essential. This article aims to assess whether stability charts and estimations can be used to establish suitable slope angles to mitigate the overwhelming cases of slope collapse in ASM. The Bieniawski’s Rock Mass Rating system and Heins and Terbrugge stability chart were used to …


Factors Influencing Household Adoption Of Rooftop Solar Power In The Philippines: An Empirical Analysis Using The Contingent Valuation Method, Rosalina Palanca-Tan Sep 2024

Factors Influencing Household Adoption Of Rooftop Solar Power In The Philippines: An Empirical Analysis Using The Contingent Valuation Method, Rosalina Palanca-Tan

Economics Department Faculty Publications

The Philippines possesses significant solar energy potential, yet the adoption of rooftop solar power (RTSP) among households remains limited despite its benefits in reducing electricity costs and contributing to the clean energy transition. This study investigates the determinants influencing households’ willingness to adopt RTSP in Metro Manila and surrounding provinces, utilizing the contingent valuation method. Survey results indicate that economic factors, particularly the potential for electricity bill reduction, along with environmental considerations, are positively associated with adoption intentions. While a substantial portion of households (82%) expressed some level of intention to adopt RTSP, the figure drops to 20% when focusing …


Utilization Of Solar And Wind Power-Generation Systems In The Mining Industry: Recent Trends And Future Prospects, Elaheh Mohammadi Valikandi, Yosoon Choi Aug 2024

Utilization Of Solar And Wind Power-Generation Systems In The Mining Industry: Recent Trends And Future Prospects, Elaheh Mohammadi Valikandi, Yosoon Choi

Journal of Sustainable Mining

In recent years, the mining industry has faced many challenges, such as rising demand, fluctuating energy prices, increasing energy consumption due to declining ore grades, and environmental concerns. According to the Paris Agreement, countries worldwide must focus on decarbonizing their economies to mitigate the global average surface temperature growth. This paper reviews how renewable energy, specifically photovoltaic and wind power systems, can be used to tackle some of these challenges. Operating mines globally, like the South Deep gold mine in South Africa and the MA'ADEN Alumina Refinery in Saudi Arabia, and abandoned mines, such as former coal mines in the …


Polish Energy Sector’S Dependence On Lignite Mining: The Process Of Transition, Marek Widera, Wojciech Naworyta, Paweł Urbański Aug 2024

Polish Energy Sector’S Dependence On Lignite Mining: The Process Of Transition, Marek Widera, Wojciech Naworyta, Paweł Urbański

Journal of Sustainable Mining

This opinion study is devoted to the role of lignite in the Polish energy sector in recent decades, i.e., after the collapse of communism in 1989. Lignite is the primary source of electricity in Poland, second only to hard coal. More than 25–35% of Polish electricity was generated by lignite-fired power plants in 1990–2022. To meet the needs of the energy industry, 46–70 Mt of lignite was mined annually in that period. Hence, Poland was, and still is, one of the world leaders in lignite production. Despite the ongoing transition of the Polish energy sector, changes occur very slowly due …


Table Of Contents, The Editors Aug 2024

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Structure Optimization Of Foam Generator For Soft Coal Seam And Foaming Effect Simulation, Jin Xin Aug 2024

Structure Optimization Of Foam Generator For Soft Coal Seam And Foaming Effect Simulation, Jin Xin

Coal Geology & Exploration

Objective The application of air screw drilling technology in gas drainage borehole within soft coal seam presents challenges, including severe dust pollution, low drill bit lifespan, and great difficulty in borehole purification. The use of air screw foam drilling technology is an effective way to solve the problem. A foam generator with good foaming performance is one of the keys to implementing the foam drilling technology. However, most current foam generators could not meet the requirements. Methods In response to this issue, a small-sized foam generator was designed based on the spiral foam generator, with an air kinetic energy conversion …


A Petrophysical Modeling-Guided Method For Predicting Parameters Of Low-Permeability Reservoirs, Wang Rui, Li Fang, Liu Shiyou, Sun Wanyuan, Li Songling, Huang Sheng Aug 2024

A Petrophysical Modeling-Guided Method For Predicting Parameters Of Low-Permeability Reservoirs, Wang Rui, Li Fang, Liu Shiyou, Sun Wanyuan, Li Songling, Huang Sheng

Coal Geology & Exploration

Backgroud Accurately predicting reservoir parameters is significant for characterizing subsurface reservoirs, establishing gas accumulation patterns, releasing production capacity, and understanding fluid migration. The traditional approaches based on core measurement or mathematical-petrophysical modeling are limited by the strong multiplicity of solutions and low accuracy of elastic parameters inversion results, making it difficult to meet the demands of modern exploration.Objective and Methods To more effectively predict reservoir parameters, this study proposed a petrophysical modeling-guided method for predicting parameters of low-permeability reservoirs. With the convolutional neural network (CNN) as a deep learning framework, the proposed method can predict water saturation, clay content, …


Production Characteristics Of Deep Coalbed Methane Wells In The Linxing Block And Associated Their Influencing Factors, Wang Zhizhuang, Wu Peng, Sun Qiang, Liu Rui, Wang Lingbo Aug 2024

Production Characteristics Of Deep Coalbed Methane Wells In The Linxing Block And Associated Their Influencing Factors, Wang Zhizhuang, Wu Peng, Sun Qiang, Liu Rui, Wang Lingbo

Coal Geology & Exploration

Objective The production characteristics of deep coalbed methane (CBM) are significantly distinguished from those of middle-shallow CBM, and even the production wells of deep CBM within the same block exhibit different characteristics. Given that relevant research remains in its exploratory stage, gaining a deeper understanding of the factors influencing the differences in production characteristics of deep CBM is significant for the production capacity prediction and production management of the subsequent large-scale production stage. Methods To determine the production characteristics of deep CBM in the Linxing block and their influencing factors, this study examined geological engineering factors including gas content, coal …


Optimization Of Schemes For Multi-Reservoir Commingled Fracturing Of Coal Measures In The Linxing Block, Wang Bo, Zhang Bing, Mi Honggang, Du Jia, Duan Jiajia, Cui Shuhui, Zhang Haozhe, Fu Tianyu Aug 2024

Optimization Of Schemes For Multi-Reservoir Commingled Fracturing Of Coal Measures In The Linxing Block, Wang Bo, Zhang Bing, Mi Honggang, Du Jia, Duan Jiajia, Cui Shuhui, Zhang Haozhe, Fu Tianyu

Coal Geology & Exploration

Objective The coal-bearing strata in the Linxing block on the eastern margin of the Ordos Basin exhibit the alternating occurrence of multiple sequences and vertical thin layers (interlayers). Therefore, multi-reservoir commingled fracturing is essential for the cost-effective, efficient exploitation of coal-measure gas from these coal-bearing strata. The key to successful multi-reservoir commingled fracturing is the achievement of expected fracture heights. The current challenges include the unclear vertically extended distance and morphologies of fractures, along with great deviations between the predicted and actual fracture heights, significantly affecting the volume of reservoirs for production growth. Methods Based on the in-situ stresses on …


Periodic Roof Deformation And Failure And Associated Water Inflow Characteristics During The Mining Of Typical Coal Seams In The Inner Mongolia-Shaanxi Contiguous Area, Zhou Zhenfang, Dong Shuning, Dong Yang, Luo Shenghu, Xue Jiankun, Wang Zhizhou, Wang Shuxuan, Shang Hongbo, Wang Tiantian, Wang Yutong, Wang Tong Aug 2024

Periodic Roof Deformation And Failure And Associated Water Inflow Characteristics During The Mining Of Typical Coal Seams In The Inner Mongolia-Shaanxi Contiguous Area, Zhou Zhenfang, Dong Shuning, Dong Yang, Luo Shenghu, Xue Jiankun, Wang Zhizhou, Wang Shuxuan, Shang Hongbo, Wang Tiantian, Wang Yutong, Wang Tong

Coal Geology & Exploration

[Objective] The disturbance of coal mine mining damages the aquifer/aquiclude structures of the overburden, causing concentrated water inflow and further affecting safe production in mines. [Methods] Using methods of the physical simulation of similar materials, numerical simulation, and on-site in situ monitoring, this study investigated the water inflow during the mining of the dominant 3-1 coal seam, typically influenced by water in sandstones on the coal seam roof, in the Inner Mongolia-Shaanxi contiguous area. By comparing the measured data of mines with similar geological and mining conditions in the surrounding area, this study delved into the periodic evolutionary patterns of …


A Non-Uniform Interpolation Method For Seismic Data Based On A Diffusion Probabilistic Model, Chen Yao, Yu Siwei, Lin Rongzhi Aug 2024

A Non-Uniform Interpolation Method For Seismic Data Based On A Diffusion Probabilistic Model, Chen Yao, Yu Siwei, Lin Rongzhi

Coal Geology & Exploration

Objective The non-uniform interpolation of seismic data is identified as a prolonged challenge in energy exploration. Since geophones cannot be precisely placed at positions corresponding to theoretical grid points, current uniform interpolation techniques frequently suffer deviations and detail distortion. Methods This study proposed a novel non-uniform interpolation method based on a diffusion probabilistic model, which is an emerging generative model in deep learning that involves the diffusion and generation processes. In the diffusion process, noise is added to the complete seismic data iteratively to train the denoising capability of the neural network. In the generation process, the neural network is …


Enrichment Patterns And Exploration Countermeasures Of Deep Coalbed Methane In The Linxing-Shenfu Block On The Eastern Margin Of The Ordos Basin, Xu Changgui, Ji Hongquan, Wang Cunwu, Zhu Xueshen Aug 2024

Enrichment Patterns And Exploration Countermeasures Of Deep Coalbed Methane In The Linxing-Shenfu Block On The Eastern Margin Of The Ordos Basin, Xu Changgui, Ji Hongquan, Wang Cunwu, Zhu Xueshen

Coal Geology & Exploration

Objective Some insights have been gained into the enrichment and accumulation patterns of deep coalbed methane (CBM) in high-rank coal seams on the eastern margin of the Ordos Basin, represented by the Daning-Jixian block. However, the exploration of deep CBM in medium-rank coal seams in the Linxing-Shenfu block, located in the northern segment of the basin's eastern margin remains in its initial stage, leading to an inaccurate and unclear understanding of the enrichment and accumulation patterns. This necessitates summarizing these patterns to effectively guide deep CBM exploration and exploitation. Methods Focusing on the Nos.8 and 9 coal seams of the …


Discovery Of A Large Gas Field Of Deep Coalbed Methane In The Shenfu Block And Its Implications, Zhu Guanghui, Ji Hongquan, Mi Honggang, Zhang Yingchun, Sun Qiang, Zhao Wei, Zhu Xueshen, Kang Lifang, Wang Yuchuan Aug 2024

Discovery Of A Large Gas Field Of Deep Coalbed Methane In The Shenfu Block And Its Implications, Zhu Guanghui, Ji Hongquan, Mi Honggang, Zhang Yingchun, Sun Qiang, Zhao Wei, Zhu Xueshen, Kang Lifang, Wang Yuchuan

Coal Geology & Exploration

Background After explorations of unconventional natural gas for nearly two decades in the Shenfu block on the eastern margin of the Ordos Basin, deep coalbed methane (CBM) with reserves of 100 billion m3 was discovered in this block in 2023. However, the preliminary exploration of deep CBM in this block faces challenges of insufficient understanding of geological laws, immature fracturing technologies, and a lack of production technologies and experience.Methods and Results Driven by both management and technological innovations, encouraging exploration results have been achieved. The management innovations include: (1) The implementation of a complementary and three-dimensional exploration model …


Predicting The “Sweet Spot” Of Deep Coalbed Methane Based On Resource Conditions And Fracability, Zhao Zhigang, Zhu Xueshen, Wang Cunwu, Zhu Yanhe, Lyu Yumin, Chen Silu, Qi Yu, Tian Yongjing Aug 2024

Predicting The “Sweet Spot” Of Deep Coalbed Methane Based On Resource Conditions And Fracability, Zhao Zhigang, Zhu Xueshen, Wang Cunwu, Zhu Yanhe, Lyu Yumin, Chen Silu, Qi Yu, Tian Yongjing

Coal Geology & Exploration

Objective China has made breakthroughs in the exploration of large-scale deep coalbed methane (CBM) reservoirs along the eastern margin of the Ordos Basin. However, effectively converting the reserves of these reservoirs into production and achieving their efficient exploitation remain unclear. Methods Based on the geological, tests, fracturing, and production performance data, this study conducted research into the assessment of geological-engineering dual “sweet spots” of deep CBM in the southern Shenfu block by focusing on the resource conditions and fracability of deep CBM reservoirs. [Results and Conclusions] Key findings are as follows: (1) The study area hosts suitable coal-forming facies zones …


Mechanical Characteristics And Fracture Propagation Mechanism Of Deep Coal Reservoirs In The Shenfu Block, Mi Honggang, Wu Jian, Peng Wenchun, Xu Lifu, Li Yong Aug 2024

Mechanical Characteristics And Fracture Propagation Mechanism Of Deep Coal Reservoirs In The Shenfu Block, Mi Honggang, Wu Jian, Peng Wenchun, Xu Lifu, Li Yong

Coal Geology & Exploration

[Objective] Clarifying the mechanical properties and in-situ stress distributions of coal seams, along with the mechanisms behind their control over the morphologies and propagation behavior of artificially induced fractures, is crucial to the fracturing design, well pattern deployment, and coalbed methane (CBM) production of deep coal seams. [Methods] This study investigated the Nos. 8 and 9 coal seams of the Taiyuan Formation in the Shenfu block in the northern portion of the eastern margin of the Ordos Basin. Using data from sonic logging, density logging, injection/falloff well tests, and production, this study systematically analyzed the mechanical …


Critical Drilling And Completion Techniques For Deep Coalbed Methane In The Shenfu Block And Their Applications, Wang Peng, Li Bin, Wang Kunjian, Zhang Hongjie, Zhang Yingchun, Du Jia, Zhang Linqiang, Wang Xiaoqi, Su Haiyan, Chen Guanghui, Yang Ruiyue Aug 2024

Critical Drilling And Completion Techniques For Deep Coalbed Methane In The Shenfu Block And Their Applications, Wang Peng, Li Bin, Wang Kunjian, Zhang Hongjie, Zhang Yingchun, Du Jia, Zhang Linqiang, Wang Xiaoqi, Su Haiyan, Chen Guanghui, Yang Ruiyue

Coal Geology & Exploration

Objective Deep coal seams exhibit high in-situ stress, moderate to high temperatures, ultra-low permeability, high compressibility, and significant heterogeneity, leading to the absence of mature technical systems for their exploitation presently. The complex geological characteristics of deep coal seams pose new technical challenges to their drilling and completion engineering, rendering it urgent to tackle theoretical and technical challenges in drilling and completion tailored to the geological characteristics of deep coal seam reservoirs. The purpose is to achieve the reserve growth and production addition of hydrocarbons in order to guarantee China’s strategic energy security. Methods Based on the pilot tests for …


Technology For Efficient Production Of Deep Coalbed Methane In The Shenfu Block, Li Bin, Yang Fan, Zhang Hongjie, Feng Lei, An Qi, Hao Zhaobing Aug 2024

Technology For Efficient Production Of Deep Coalbed Methane In The Shenfu Block, Li Bin, Yang Fan, Zhang Hongjie, Feng Lei, An Qi, Hao Zhaobing

Coal Geology & Exploration

Objective Deep coalbed methane (CBM), representing one crucial resource successor for ensuring the oil and gas security of China and achieving peak carbon dioxide emissions and carbon neutrality of the country, exhibits broad prospects for production. However, due to the small low universality of CBM production technologies under varying geological conditions, a technology that has been successfully applied in some blocks cannot be directly extended to other blocks. This leads to blind deployment of well types and well patterns in the early-stage exploration and development of new blocks to a certain extent. Given this, it is necessary to develop a …


Pore Structure And Differential Fluid Occurrence Of Deep Coal Seams, Wu Jian, Sun Qiang, Shi Xuefeng, Gao Lijun Aug 2024

Pore Structure And Differential Fluid Occurrence Of Deep Coal Seams, Wu Jian, Sun Qiang, Shi Xuefeng, Gao Lijun

Coal Geology & Exploration

Objective Breakthroughs have been achieved in deep coalbed methane (CBM) exploration along the eastern margin of the Ordos Basin, exhibiting the characteristics of local breakthroughs but regional differential CBM production in multiple blocks. The pores and fractures in deep coal reservoirs, serving as the material spaces for fluid occurrence and occurrence, are critical to the differential development across deep CBM blocks. Methods In this study, coal samples were collected systematically from the deep part of the Shenfu block located along the eastern margin of the Ordos Basin. Using conventional tests on porosity, permeability, and physical properties, as well as CO …


Fracturing Characteristics And Instability Modes Of Deep Primary Coal-Rock Combinations Under Triaxial Compression, Li Chunyuan Aug 2024

Fracturing Characteristics And Instability Modes Of Deep Primary Coal-Rock Combinations Under Triaxial Compression, Li Chunyuan

Coal Geology & Exploration

[Objective] Deep coal-bearing strata contain primary interfaces and layered composite structures. Under the mining disturbance, the fracturing and instability of the primary composite structures of layered coal-rock combinations prove to be a principal cause of disasters such as water inrushes. [Methods] This study aims to explore the impacts of the structures of deep primary coal-rock combinations on the stability of layered rock masses during coal mining. Using fracturing tests under triaxial compression and CT-based reconstruction conducted in the laboratory, this study determined the fracturing differences between deep primary coal-rock combinations and single coal or rock masses. Based on the analyses …


A Cylindrical Permeation And Diffusion Model For Bingham Grout In Water-Rich Sand Layers And Its Experimental Research, Wang Xuesong, Cheng Hua, Yao Zhishu, Rong Chuanxin, Xie Bao Aug 2024

A Cylindrical Permeation And Diffusion Model For Bingham Grout In Water-Rich Sand Layers And Its Experimental Research, Wang Xuesong, Cheng Hua, Yao Zhishu, Rong Chuanxin, Xie Bao

Coal Geology & Exploration

Objective The disaster prevention and control for water-rich sand layers pose a major challenge to the safe construction of tunnels and deep foundation pits. Typically, the impermeability and bearing capacity of highly water-rich and weakly cemented sand layers are enhanced through permeation grouting via sleeve valve tubes, with resulting grouting concretions being approximately cylindrical. Methods To explore the cylindrical diffusion mechanism of permeation grouting in sand layers, this study constructed a cylindrical diffusion model of radial tube flow for the permeation grouting of Bingham grout in sand layers while considering the tortuosity effects. Subsequently, this study developed a set of …


Characteristics And Transformations Of Mineral Phases In Burnt Rocks, Yalikun Rexiti, Huang Lei, Yang Fan, Xue Xiaoyuan, Song Shijun, Hu Jian, Zhang Zeyu, Ji Zhongkui Aug 2024

Characteristics And Transformations Of Mineral Phases In Burnt Rocks, Yalikun Rexiti, Huang Lei, Yang Fan, Xue Xiaoyuan, Song Shijun, Hu Jian, Zhang Zeyu, Ji Zhongkui

Coal Geology & Exploration

Objective Burnt rocks are special rocks formed by the surrounding rocks that are baked due to the spontaneous combustion of coal seams. They are extensively distributed in the Yan’an Formation on the northeastern margin of the Ordos Basin. However, the characteristics and formation mechanisms of burning-associated mineral phases in these rocks remain unclear. Methods This study conducted analytical tests and high-temperature heating simulations of protolith to analyze the mineral phases of underground burnt rocks in the Zhangjiamao Coal Mine, Shaanxi Province. Results and Conclusions The results indicate that the underground burnt rocks exhibit enrichment in mafic components, abnormal migration of …