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Articles 60331 - 60360 of 302622

Full-Text Articles in Physical Sciences and Mathematics

Forward Simulation Of Fault Detection By Transmitting Channel Wave In Thin Alternating Coal Seams, Ma Yanlong Apr 2021

Forward Simulation Of Fault Detection By Transmitting Channel Wave In Thin Alternating Coal Seams, Ma Yanlong

Coal Geology & Exploration

In order to study the feasibility of the fault detection by transmitting channel wave in thin alternating coal seams of southwestern region, a representative area was selected, and a coal mine in Panzhihua Coal Industry Group was selected as the research object. A three-dimensional geological model with three alternating coal seams containing three partings, three partings and faults and without parting was established based on actual geological data. Through the forward simulation and analysis of the characteristics of the wave field and the frequency dispersion of the channel waves of the three dimensional elastic wave, the validity of the amplitude …

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Rock Breaking Mechanism Of Composite Impact Of Full-Size Pdc Bit Based On Finite Element Analysis, Peng Xu, Hao Shijun Apr 2021

Rock Breaking Mechanism Of Composite Impact Of Full-Size Pdc Bit Based On Finite Element Analysis, Peng Xu, Hao Shijun

Coal Geology & Exploration

In order to solve the problems of low rock breaking efficiency in hard formation and the decrease of bit life caused by stick-slip vibration of drilling tools, the full-size bit composite impact rock breaking mechanism was studied by finite element method(ANSYS). The effects of impact frequency, WOB(weight on bit) and rotational speed on the efficiency of rock breaking were analyzed. It was found that both tensile and compressive stresses existed in rock during bit rock breaking, and rock failure was manifested in comprehensive failure of “tensile & compressive shear”. It is concluded that under the condition of torsional impact frequency …

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Difficulties And Optimization Of Wire-Line Core Drilling Technology For Broken Formation In Complex Structure Area Of Northwest Hunan, Kong Xiangwang, Zhang Shaohe, Wang Wenbin, Sun Pinghe, Wu Dongyu, Xiao Jincheng, He Hongsheng Apr 2021

Difficulties And Optimization Of Wire-Line Core Drilling Technology For Broken Formation In Complex Structure Area Of Northwest Hunan, Kong Xiangwang, Zhang Shaohe, Wang Wenbin, Sun Pinghe, Wu Dongyu, Xiao Jincheng, He Hongsheng

Coal Geology & Exploration

Taking Xiangcidi 1 Well in the complex structural area of northwest Hunan as an example, in view of the common drilling difficulties encountered during the drilling process such as low core adoption rate and stuck-drilling buried drilling, we adopted the self-developed pumpless reverse circulation advanced side spray line and optimized the drilling fluid system to effectively improve the core drilling rate of the drilling project. The new type of drilling tool can form a local reverse circulation at the bottom of the hole, and combined with the internal anti-clogging cone net of the drilling tool and the design of the …

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Table Of Contents, The Editors Apr 2021

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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Geological Unit Division And Development Countermeasures Of Deep Coalbed Methane In Southern Yanchuan Block, Chen Zhenlong Apr 2021

Geological Unit Division And Development Countermeasures Of Deep Coalbed Methane In Southern Yanchuan Block, Chen Zhenlong

Coal Geology & Exploration

Deep coalbed methane resources have great potential, accounting for 62.8% of the total resources. However, effective development faces many challenges such as strong heterogeneity, high geostress, difficult process matching and low production capacity. Taking the deep coalbed methane in Southern Yanchuan Block as an example, the key parameters are overlaid and analyzed, the development geological units of the gas field are finely divided according to the five controlling factors of “sedimentation coal-control, tectonic influenced accumulation, hydrodynamic gas-control, geostress seepage-control, physical property production-control”. The key geological attributes and development constraints of each development geological unit are clarified, and the differentiated development …

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Study On The Main Controlling Geological Factors Of High Yield Deep Cbm In Southern Yanchuan Block, Gao Yuqiao, Li Xin, He Xipeng, Chen Zhenlong, Chen Gang Apr 2021

Study On The Main Controlling Geological Factors Of High Yield Deep Cbm In Southern Yanchuan Block, Gao Yuqiao, Li Xin, He Xipeng, Chen Zhenlong, Chen Gang

Coal Geology & Exploration

The Southern Yanchuan Block belongs to a deep, high-rank coalbed methane(CBM) reservoir. Due to the influence of geological conditions, the single well productivity varies greatly. Researching on the main controlling geological factors and their changing mechanism of CBM accumulation, combined with the dynamic data of CBM development, the main controlling geological factors of the CBM well enrichment and high production are analyzed. The research results show that the productivity of the gas field is controlled by the geological factors of “tectonic, hydrology, coal structure”. Tectonic restricts the accumulation of CBM; the degree of salinity characterizes affects the preservation of CBM; …

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Causes For Low Cbm Production Of Vertical Wells And Efficient Development Technology In Northern Zhengzhuang Block In Qinshui Basin, Jia Huimin, Hu Qiujia, Fan Bin, Mao Chonghao, Zhang Qing Apr 2021

Causes For Low Cbm Production Of Vertical Wells And Efficient Development Technology In Northern Zhengzhuang Block In Qinshui Basin, Jia Huimin, Hu Qiujia, Fan Bin, Mao Chonghao, Zhang Qing

Coal Geology & Exploration

In order to realize the efficient development of deep CBM in the north of Zhengzhuang block in Qinshui Basin, firstly, the geological conditions and development data of coal reservoir are deeply analyzed, and the development data of shallow CBM are compared. Secondly, based on the evaluation of gas content, the difficulty of coalbed methane recovery is evaluated by comprehensive evaluation of reservoir permeability, reservoir-desorption pressure difference, coal structure and in-situ stress state-Finally, the reasons for low production of CBM wells in the northern Zhengzhuang Block are clarified, and the adaptive technology for efficient development is put forward. The results show …

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Numerical Simulation Of The Influence Of No-Flow Recharge Aquifer On Cbm Drainage, Liu Bing, Zhang Songhang, Tang Shuheng, Wang Pengfei, Zhai Jiayu, Ji Chaoqi Apr 2021

Numerical Simulation Of The Influence Of No-Flow Recharge Aquifer On Cbm Drainage, Liu Bing, Zhang Songhang, Tang Shuheng, Wang Pengfei, Zhai Jiayu, Ji Chaoqi

Coal Geology & Exploration

Coalbed methane wells in southern Qinshui Basin have the characteristics of high water yield and low gas yield, while some wells present high water yield and high gas yield characteristics. Generally speaking, the high water yield of coalbed methane wells is mostly related to the aquifer with recharge. In this case, based on the coal reservoir geological condition of Shizhuangnan Block and the actual situation of coalbed methane vertical well production, the influence of non-flow recharge aquifer on reservoir pressure variation and CBM outflow rule was simulated by using a three-dimensional coal reservoir simulation software (SIMEDWin) with gas and water …

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Numerical Simulation And Test Of Gas Drainage With Water Jet Layered Pressure Relief And Permeability Enhancement In Soft Coal Seam, Liu Xiao, Li Yong, Xuan Dequan, Hu Shixiong, Jing Tianxiang, Xu Sen Apr 2021

Numerical Simulation And Test Of Gas Drainage With Water Jet Layered Pressure Relief And Permeability Enhancement In Soft Coal Seam, Liu Xiao, Li Yong, Xuan Dequan, Hu Shixiong, Jing Tianxiang, Xu Sen

Coal Geology & Exploration

Hydraulic punching is the main technical measure to enhance permeability and drainage of coal seam gas. The pressure relief effect is mainly evaluated by the coal output. However, there are some problems such as large coal output, uneven pressure relief and easy stress concentration. Therefore, this paper puts forward the soft coal interlayer water jet layered pressure relief and permeability increasing gas drainage technology. Considering the influence of gas pressure compression and coal matrix adsorption gas expansion on the coal mass deformation, a multiphysics theoretical model under the coupling condition of stress field, fracture field and seepage field was established. …

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The Enrichment And High Yield Law Of Cbm In Yanjiao Syncline In Zhijin Block, Guizhou Province, Guo Tao Apr 2021

The Enrichment And High Yield Law Of Cbm In Yanjiao Syncline In Zhijin Block, Guizhou Province, Guo Tao

Coal Geology & Exploration

In view of the problems such as the large number of coal seams, the thin single layer, the complex structure, much mylonite coal and hard to evaluate favorable area in southern China, this paper makes use of the exploration achievements and tests data of Zhijin Block to study the reservoir-forming conditions of multiple coal seam CBM. The results show that the enrichment and high yield CBM in south China is characterized by “sedimentation storage-control, preservation gas-control, geostress coal structure control production”. The thickness, number and quality of coal are controlled by sedimentation, which determines the resource base of coal bed …

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Practice Of Enhanced Gas Extraction By Staged Fracturing With Comb-Shaped Long Hole In Coal Mine Roof, Jia Bingyi, Chen Dongdong, Wu Jie, Sun Siqing, Wang Jianli, Zhao Jizhan, Zhang Jie Apr 2021

Practice Of Enhanced Gas Extraction By Staged Fracturing With Comb-Shaped Long Hole In Coal Mine Roof, Jia Bingyi, Chen Dongdong, Wu Jie, Sun Siqing, Wang Jianli, Zhao Jizhan, Zhang Jie

Coal Geology & Exploration

In order to solve the problems of drilling construction difficulty, low gas drainage concentration, poor drainage effect and inability to realize the predrainage of large area, based on the existing directional drilling technology and hydraulic fracturing technology in coal mines, combined with the previous research results, the staged hydraulic fracturing technology of comb-shaped long borehole in roof was proposed, and the field test was carried out in Sangshuping No.2 well in Hancheng mining area.The test results show that the main hole length of comb-shaped hole in roof was 588 m, including 8 branch holes, the total drilling footage was 1 …

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3d Geological Model Construction And Error Analysis Of Intelligent Mining Working Face, Wang Xinmiao, Han Baoshan, Song Tao, Shen Kai, Yue Hui, Lei Xiaoyu Apr 2021

3d Geological Model Construction And Error Analysis Of Intelligent Mining Working Face, Wang Xinmiao, Han Baoshan, Song Tao, Shen Kai, Yue Hui, Lei Xiaoyu

Coal Geology & Exploration

The complexity of geological conditions is one of the key issues affecting the further development of current intelligent mining, and there is an urgent need to build a high-precision 3D geological model of the mining face. This article analyzes the construction method of the intelligent mining geological model, and takes an intelligent working face of Huangling No.1 Mine as an example, combines all the geological exploration data of the working face, and uses the TIM-3D modeling software to construct the initial static model and the working face respectively. The dynamic model of the working face is equipped with a transparent …

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Different-Source Prediction Of Gas Emission Based On Sapso-Elm And Its Application, Ren Haifeng, Yan Youji, Wu Qinghai Apr 2021

Different-Source Prediction Of Gas Emission Based On Sapso-Elm And Its Application, Ren Haifeng, Yan Youji, Wu Qinghai

Coal Geology & Exploration

In order to improve the accuracy of gas emission prediction, in view of the multiple correlations and complexity of the influencing factors of gas emission, principal component analysis and separated source prediction theory were combined, the gas emission data of the mining layer, adjacent layer, and goaf were respectively subjected to principal component analysis to reduce dimensionality, and the predictor was obtained. Aiming at the problem that the input weight matrix and hidden layer threshold of the extreme learning machine were generated randomly, the simulated annealing particle swarm optimization algorithm was used to optimize the parameters of the extreme learning …

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Mechanism And Control Of Strong Ground Pressure In Fully Mechanized Mining Face, Zhang Yin, Zhao Yi, Li Hao Apr 2021

Mechanism And Control Of Strong Ground Pressure In Fully Mechanized Mining Face, Zhang Yin, Zhao Yi, Li Hao

Coal Geology & Exploration

In order to ensure the safe use of the withdrawal roadway in the fully mechanized mining face of thick coal seam, taking the strong ground pressure behavior of the withdrawal roadway in 31102 working face of Nalinhe No.2 well as the method of combination of field monitoring and theoretical analysis, the strong ground pressure behavior of the withdrawal roadway in the mining process of fully mechanized mining face in thick coal seam was studied. The results show that: the strong ground pressure behavior of withdrawal roadway in fully mechanized mining face of thick coal seam is mainly the result of …

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Comprehensive Exploration Of Collaps Column And Three-Dimensional Construction Technology Of Water Plug Based On Directional Horizontal Drilling, Tian Gan, Nan Shenghui, Lin Xudong, Fan Juan Apr 2021

Comprehensive Exploration Of Collaps Column And Three-Dimensional Construction Technology Of Water Plug Based On Directional Horizontal Drilling, Tian Gan, Nan Shenghui, Lin Xudong, Fan Juan

Coal Geology & Exploration

The Ordovician limestone water inrush from floor caused by water-conducted collapse columns is the main water hazard threat in Tashan Mine of Tongmei Group. Water inrush from collapse columns once happened in the roadway excavation of 8228 working face. On the basis of comprehensive geophysical exploration above and below the well, the development boundary, the influence zone, the cementation of the fractured body and the distribution characteristics of the water flowing subsided column are found out by means of multi-layer and multi-branch surface directional horizontal drilling speed logging, drilling fluid leakage, cuttings logging and logging while drilling, and combined with …

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Effect Of Arbuscular Mycorrhizal Fungi And Hippophae Rhamnoides On The Improvement Of The Dump Of Open-Pit Coal Mine In The Eastern Grassland, Miao Chunguang, Yang Huihui, Bi Yinli, Song Ziheng, Guo Nan Apr 2021

Effect Of Arbuscular Mycorrhizal Fungi And Hippophae Rhamnoides On The Improvement Of The Dump Of Open-Pit Coal Mine In The Eastern Grassland, Miao Chunguang, Yang Huihui, Bi Yinli, Song Ziheng, Guo Nan

Coal Geology & Exploration

The land barren, grassland degradation and difficult ecological restoration are serious in the open-pit mining area of eastern China. The symbiosis between arbuscular mycorrhizal fungi(AMF) and Hippophae rhamnoides and the effect of mycorrhiza on the development of Hippophae rhamnoides root system and the improvement of soil in the dumping site were analyzed. It was found that the plant height and crown width of inoculated AMF(+M) were increased by 20% and 21%, respectively. The root length and root volume of +M were 1.46 and 1.97 times of CK, respectively. The content of Glomalin in the rhizosphere soil of Hippophae rhamnoides in …

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Beneficial Cbm Area Prediction Based On Structural Elemental Quantitative Cluster Classification, Liu Jing, Chang Suoliang, Liu Zuiliang, Zhang Sheng, Chen Qiang, Liu Bo Apr 2021

Beneficial Cbm Area Prediction Based On Structural Elemental Quantitative Cluster Classification, Liu Jing, Chang Suoliang, Liu Zuiliang, Zhang Sheng, Chen Qiang, Liu Bo

Coal Geology & Exploration

In order to select optimally the CBM-enriched area of structural elements and delicately divide the advantageous blocks of CBM structural control under the development scale, this paper takes the Yongle south block in the southwest of Qinshui Basin as an example, subdivides the structural characterization elements and quantifies the indicators of structural elements, and puts forward the method of trend surface iteration to characterize different degrees of structural deformation, fuzzy clustering classification and element dichotomy to optimize the favorable area of CBM structural control. Based on the comprehensive interpretation results of seismic geology, the quantitative characterization of structural elements of …

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Numerical Simulation Of Safe Distance Through Roadway Drilling Under Dynamic Load Of Large Diameter Rescue Well, Li Bizhi, Hao Shijun, Liu Mingjun, Zhang Qiang, Bai Gang, Mo Haitao Apr 2021

Numerical Simulation Of Safe Distance Through Roadway Drilling Under Dynamic Load Of Large Diameter Rescue Well, Li Bizhi, Hao Shijun, Liu Mingjun, Zhang Qiang, Bai Gang, Mo Haitao

Coal Geology & Exploration

Aiming at the sudden inburst of formation water and drilling fluid into a roadway along the borehole during through roadway drilling operation, which results in the secondary injury of the trapped personnel, ABAQUS geotechnical numerical simulation method was adopted, the model was established with the surface rescue well of the roadway of No.3 coal seam in Pingshang Coal Mine as an example, the plastic deformation characteristics of the surrounding rock of the roadway roof and the optimization of safe through roadway distance under drilling dynamic disturbance were studied. The results show that the dynamic disturbance caused displacement deformation and plastic …

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Lesson Plan - Land Use Game: Complex Decisions, Center For Urban Resilience Apr 2021

Lesson Plan - Land Use Game: Complex Decisions, Center For Urban Resilience

Module 02: Land Use

The purpose of this lesson is for students to simulate decisions that may influence land use patterns in a city. To do this, the students will play a board game that has both mandated Policy Event cards and decision cards that students control. The decision cards consist of three potential options and each option has different monetary, ecological, and social consequences. The students play the game in groups of two to three and then discuss the impacts of their decisions on the future of their city. The lesson concludes with a discussion of how well the data collection went and …

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Powerpoint - Land Use, Center For Urban Resilience Apr 2021

Powerpoint - Land Use, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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Land Use Game, Center For Urban Resilience Apr 2021

Land Use Game, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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Action Plan Rubric, Center For Urban Resilience Apr 2021

Action Plan Rubric, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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Decisions Cards, Center For Urban Resilience Apr 2021

Decisions Cards, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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Game Board, Center For Urban Resilience Apr 2021

Game Board, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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Policy Event Cards, Center For Urban Resilience Apr 2021

Policy Event Cards, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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Land Use Game Instructions And Play, Center For Urban Resilience Apr 2021

Land Use Game Instructions And Play, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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Lesson Plan - Biophysical And Social Drivers, Center For Urban Resilience Apr 2021

Lesson Plan - Biophysical And Social Drivers, Center For Urban Resilience

Module 02: Land Use

In this lesson, students will learn about the various biophysical and social drivers which impact land use in detail. They will then use their knowledge about urban land use as a class to explore various data sources (maps, charts, figures, etc.) to determine how these drivers have influenced land use in New Orleans. Students will then relate their understanding of the case study to the Ecological Services Model.

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Powerpoint - New Orleans: A Case Study, Center For Urban Resilience Apr 2021

Powerpoint - New Orleans: A Case Study, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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Reading - Social And Biophysical Drivers Of Urban Ecosystems, Center For Urban Resilience Apr 2021

Reading - Social And Biophysical Drivers Of Urban Ecosystems, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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New Orleans Elevation Handout, Center For Urban Resilience Apr 2021

New Orleans Elevation Handout, Center For Urban Resilience

Module 02: Land Use

No abstract provided.

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