Convection - Heat Transfer Coupling Mechanism For Closed-Loop Heat Extraction From Hydrothermal Resources Using Horizontal Wells,
2024
CNOOC Gas and Power Group, Beijing 100028, China
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,
2024
Central Mining Institute – National Research Institute, Plac Gwarkow 1, 40-166 Katowice, Poland
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,
2024
University of Johannesburg, Department of Mining Engineering and Mine Survey South Africa
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,
2024
Ateneo de Manila University
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,
2024
Pukyong National University, Department of Energy Resources Engineering, Busan 48513, Korea
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,
2024
Institute of Geology, Adam Mickiewicz University, Poznań, Poland
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 …
Structure Optimization Of Foam Generator For Soft Coal Seam And Foaming Effect Simulation,
2024
Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Changsha 410083, China; School of Geosciences and Info-Physics, Central South University, Changsha 410083, China; CCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, China
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 …
Periodic Roof Deformation And Failure And Associated Water Inflow Characteristics During The Mining Of Typical Coal Seams In The Inner Mongolia-Shaanxi Contiguous Area,
2024
College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China; CCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, China; Shaanxi Key Laboratory of Preventing and Control Technology for Coal Mine Water Hazard, Xi’an 710077, China; Shaanxi Engineering Research Center of Mine Ecological Environment Protection and Restoration in the Middle of Yellow River Basin, Xi’an 710077, China
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 …
Mechanical Characteristics And Fracture Propagation Mechanism Of Deep Coal Reservoirs In The Shenfu Block,
2024
China United Coalbed Methane Co., Ltd., Beijing 100016, China; Provincial Center of Technology Innovation for Coal Measure Gas Co-production, Taiyuan 030008, China
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 …
Technology For Efficient Production Of Deep Coalbed Methane In The Shenfu Block,
2024
China United Coalbed Methane Co., Ltd., Beijing 100016, China; Provincial Center of Technology Innovation for Coal Measure Gas Co-production, Taiyuan 030008, China
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,
2024
China United Coalbed Methane Co., Ltd., Beijing 100016, China; Provincial Center of Technology Innovation for Coal Measure Gas Co-production, Taiyuan 030008, China
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 …
Characteristics And Transformations Of Mineral Phases In Burnt Rocks,
2024
Department of Geology, Northwest University, Xi’an 710054, China
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 …
Seismic Data Denoising Based On The Convolutional Neural Network With An Attention Mechanism In The Curvelet Domain,
2024
School of Geological Engineering and Geomatics, Chang’an University, Xi’an 710054, China; Key Laboratory of Mine Geological Hazards Mechanism and Control, Ministry of Natural Resources, Xi’an 710054, China; National Engineering Research Center of Offshore Oil and Gas Exploration, Beijing 100028, China
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 …
Characteristics Of Gas Bursting And Application Of Layered Cutting Drilling In Outburst Coal Seam,
2024
School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454003, China; Collaborative Innovation Center of Coal Work Safety and Clean High Efficient Utilization, Jiaozuo 454003, China
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,
2024
China Coal Technology and Engineering Group (CCTEG)
Enrichment Patterns And Exploration Countermeasures Of Deep Coalbed Methane In The Linxing-Shenfu Block On The Eastern Margin Of The Ordos Basin,
2024
China National Offshore Oil Corporation, Beijing 100010, China
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,
2024
CNOOC Ltd., Beijing 100010, China; Provincial Center of Technology Innovation Center of Coal Measure Gas Co-production, Taiyuan 030008, China
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,
2024
CNOOC Research Institute Co., Ltd., Beijing 100028, China
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 …
Critical Drilling And Completion Techniques For Deep Coalbed Methane In The Shenfu Block And Their Applications,
2024
China United Coalbed Methane Co., Ltd., Beijing 100016, China; Provincial Center of Technology Innovation for Coal Measure Gas Co-production, Taiyuan 030008, China
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 …
Production Characteristics Of Deep Coalbed Methane Wells In The Linxing Block And Associated Their Influencing Factors,
2024
China United Coalbed Methane Co., Ltd., Beijing 100016, China; Provincial Center of Technology Innovation for Coal Measure Gas Co-production, Taiyuan 030008, China
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 …
