Engineering Commons^™

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

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 …

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 …

A Step By Step Shoreline Attribute Analysis For Selected Waterbodies In The Gulf Of Mexico To Promote The Use Of Living Shorelines, Christoper Boyd, Xutong Niu, Taylor R. Horn

The Journal of Extension

Living Shorelines are being promoted by coastal extension professionals as a more resilient nature-based solution to control shoreline erosion. The Virginia Institute of Marine Sciences Living Shorelines Suitability Model was run in selected waterbodies within the Gulf of Mexico.

The locations of the selected water bodies, coastal data sets used, and shoreline protection recommendations generated by the Model are presented. A step-by-step statistical analysis conducted through ArcGIS Pro from these selected coastal shorelines will illustrate how extension professionals with novice GIS experience can use the model output to promote living shorelines to coastal property owners, city managers, and developers.

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 …

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, …

Processing Of Impulse Noise In Magnetotelluric Data Based On Bidirectional Recurrent Imputation, Yang Kai, Liu Cheng, Li Han, He Jinglong

Coal Geology & Exploration

Objective Magnetotelluric sounding is an exploration method to obtain the underground electrical structure by observing the natural electromagnetic field, which is easily disturbed by noise. Impulse noise, frequently occurring in magnetotelluric sounding, generally exhibits high amplitude and wide frequency bands, producing significant impacts on the data quality. Methods To suppress such noise, this study proposed a method based on a bidirectional recurrent imputation for time series (BRITS) model. First, the data segments with noise interference were deleted. Second, for the magnetotelluric time series with missing data to be imputed, training sets were constructed for imputation training of the BRITS model. …

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 …

Characteristics Of Gas Bursting And Application Of Layered Cutting Drilling In Outburst Coal Seam, Wang Yonglong, Zhao Aoqi, Yu Zaijiang, Wang Zhenfeng, Liu Xiao, Ma Denghui, Zhang Hui, Liu Chun

Coal Geology & Exploration

Objective The overlimit gas bursting in the drilling process of outburst coal seam is a safety hazard that threatens the efficient production of the mine. The layered cutting drilling method helps to weaken the burst gas pressure in the borehole, but the characteristics of gas release around the trapezoidal borehole formed by layered cutting are unknown, which limits the structural design and application effect of the layered cutting drilling tool. Methods Herein, study was conducted based on the layered cutting boreholes with different layer spacing and layer thickness difference. Specifically, a mathematical model was established to analyze the gas flow …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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

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 …

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

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 …

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 …

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 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 …

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

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

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

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

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 …

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 …

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 …

Artificial Intelligence Logging: Fundamental, Principle, Technique, And Application, Cheng Xi, Ren Zhanli

Coal Geology & Exploration

Background Intelligent hydrocarbon exploration and exploitation have become a trend and hot research topic in the oil and gas industry. Artificial intelligence logging (AIL) exhibits considerable potential to address challenges in the explore-exploit of unconventional hydrocarbon resources, as well as resources in complex environments in the deep earth and deep ocean. However, the driving mode, fundamental, implementation principle, structure, and application scenarios of AIL remain understudied. Objective and Methods To build a comprehensive ecology of the AIL system and thoroughly explore and reveal the potential and value of AIL, this study employed methods like literature analysis, theoretical research, technical analysis, …

Seismic Data Denoising Based On The Convolutional Neural Network With An Attention Mechanism In The Curvelet Domain, Bao Qianzong, Zhou Mei, Qiu Yi

Coal Geology & Exploration

[Objective] Noise in seismic data significantly affects the accurate interpretation of subsurface stratigraphic information. Given that effective signals with pronounced lateral correlations in seismic data are distributed in specific coefficients but random noise typically spreads uniformly over all coefficients in the curvelet domain, more effective separation of signals can be achieved. [Methods] The convolutional neural network based on the attention mechanism can adaptively extract key information by focusing on important features of images. Hence, this study proposed a noise attenuation method for seismic data using a convolutional neural network based on the curvelet transform and attention mechanism (Curvelet-AU-Net). First, the …

Coal Mines In Light Of The Provisions Of The Proposed Regulation Of The European Parliament And Of The Council On The Reduction Of Methane Emissions In The Energy Sector, Amending Regulation (Eu) 2019/942, Magdalena Zięba, Jacek Skiba, Piotr Kalisz, Regina Kościarz, Adam Smoliński

Journal of Sustainable Mining

In December 2021, the European Commission presented a draft Regulation of the European Parliament and of the Council on the reduction of methane emissions in the energy sector and amending Regulation (EU) 2019/942. The article summarizes the proposed EU rules on methane emissions from coal mines. In addition, it summarizes the figures of anthropogenic methane emissions for the European Union countries from the three main emission sources: agriculture, waste and the energy sector. The volumes of methane emissions from EU and Polish coal mines are also presented and divided into underground and surface mines, as well as active mines, abandoned …

Spatio-Temporal Changes In The Gravity And Post-Mining Seismic Activity In Abandoned Deep Coal Mine Kazimierz-Juliusz During Flooding, Andrzej Kotyrba, Łukasz Kortas, Sławomir Siwek

Journal of Sustainable Mining

The flooding of an underground hard coal mine, resulting in the filling of post-mining voids (workings and goafs) and the repeated saturation of pore and interstitial spaces of the adjacent rock with water, change the mass and its distribution in the near-surface part of the earth’s crust. This process is slow and lasts many years. As a result, the local gravity field undergoes dynamic changes. It depends on the surface morphology and the density of geological strata, which is related to their water content. Changes in the local gravity field can be monitored by periodic gravity surveys performed in the …

Enhancing Fuel Injection System Reliability Through Weibull Family Functions Analysis, Ali Nouri Qarahasanlou, Abbas Barabadi, Meisam Saleki, Ali Rahimazar, Parisa Rezakhania, Masoume Gholamia

Journal of Sustainable Mining

The efficient operation of heavy machinery is crucial to the success of mining and civil construction operations. To guarantee this performance, equipment performance is assessed using the Reliability Index, which analyzes failures to study the ability of a system to carry out its intended functions under predetermined conditions. On the other hand, the failure rate and operational environmental condition (such as management decisions, maintenance performance, etc., that are defined as “risk factors”) over the life cycle of industrial systems pose a significant challenge to reliability analysis. This paper proposes an approach to address these challenges by extending Weibull family functions …

Pilot Experiment For Underground In-Situ Pyrolysis Of Tar-Rich Coal In The Northern Shaanxi Province, Duan Zhonghui, Yang Fu, Wang Zhendong, Ma Li, Duan Xiaoqing, Cao Husheng, Chen Liang

Coal Geology & Exploration

Objective The breakthrough of the pilot experiment for underground in-situ pyrolysis of tar-rich coal in the northern Shaanxi has added new vitality to the research on in-situ conversion of fossil energy such as tar-rich coal and oil shale, and the results have attracted wide attention both inside and outside the industry. The research on underground in-situ pyrolysis of tar rich coal is still in its infancy, lacking systematic research on field engineering data.Methods Based on the pilot experiment, the main geological conditions and engineering difficulties have been clarified, and the progress of underground in-situ pyrolysis has been summarized. The …