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Articles 2581 - 2610 of 4587

Full-Text Articles in Mining Engineering

Reasons Of Low Yield And Stimulation Measures For Cbm Wells In Junlian Area, Li Ying, Zheng Rui, Luo Kai, Zhu Yanming, Zhang Yimin Aug 2020

Reasons Of Low Yield And Stimulation Measures For Cbm Wells In Junlian Area, Li Ying, Zheng Rui, Luo Kai, Zhu Yanming, Zhang Yimin

Coal Geology & Exploration

Coalbed methane fields in Junlian area have good development potential, but the existence of a large number of low-production and low-efficiency wells has restricted the increase of productivity. This paper analyzes the coupling relationship between high-productivity wells and geological factors from the perspective of geological engineering integration, analyzes the causes of inefficient wells from three aspects of geology, drainage and engineering, and evaluates the corresponding reform measures. The results show that the formation of inefficient wells in the north and the west of the study area is mainly affected by gas-bearing properties, fault distribution, production horizons, production and drainage rhythms, …

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Geochemical Characteristics And Their Origin Of Cbm In Xingxian Area, Ordos Basin, Wang Xiangye, Sun Baoping Aug 2020

Geochemical Characteristics And Their Origin Of Cbm In Xingxian Area, Ordos Basin, Wang Xiangye, Sun Baoping

Coal Geology & Exploration

The distribution of carbon and hydrogen isotope of methane is of signification in revealing the origin, the distribution of CBM reservoir, and the source evaluation of CBM. To study the origins of coalbed methane and carbon dioxide, the data of the components、carbon and hydrogen isotopes of CBM from the desorption gas of coal core from Xingxian area were analyzed. With the CBM origins chart board, and the geological environment, the geological effect of the formation and the evolution of CBM were analyzed. the ratios of CBM with different origins were estimated. The results show that the δ13C, values …

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Corrosion And Degradation Of Feldspar Sandstone In Acidic Environment, Zhou Bin, Zhang Dongming, Xu Jiang, Cheng Liang, Li Jiaxin Aug 2020

Corrosion And Degradation Of Feldspar Sandstone In Acidic Environment, Zhou Bin, Zhang Dongming, Xu Jiang, Cheng Liang, Li Jiaxin

Coal Geology & Exploration

In order to study the effect of acidic environment on the corrosion and deterioration of rocks, CT images processing technology was used to analyze the meso-composition and structural changes of feldspar sandstone after soaking in acidic water. Shimadzu AGI-250 servo material testing machine was used to carry out uniaxial compression test to observe the deterioration of mechanical parameters. The results show that the total density of the feldspar sandstone decreased Ofter the acidic environment treatment, the distribution trend is homogeneous, and the mineral with higher density is formed in the local area. The secondary pores of the feldspar sandstone increased …

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Sensitivity Analysis Of Disaster-Pregnant Environmental Factors For Slope Geological Hazards In Kaiyang County, Guizhou Province, Qin Yigen, Yang Genlan, Xie Jin, Liu Bangyu Aug 2020

Sensitivity Analysis Of Disaster-Pregnant Environmental Factors For Slope Geological Hazards In Kaiyang County, Guizhou Province, Qin Yigen, Yang Genlan, Xie Jin, Liu Bangyu

Coal Geology & Exploration

The geological conditions are complex in Kaiyang County, and geological disasters occur frequently. On the basis of field geological hazard investigation, 8 factors including elevation, slope, slope direction, engineering petrofabric, slope structure, fault, drainage and NDVI value are selected as the disaster-pregnant factors of slope geohazards. Based on the GIS platform, and by using the certainty factor model(CF) and the sensitivity-exponential(E), susceptibility of these 8 factors are researched. The results show that the areas with elevation from 515 to 993 m, the slope degree from 20° to 50°, the aspect of the west, the northwest and the southeast, …

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Study On The Effect Of Dual-Freedom Coupling Between The Tilt Geophones And The Surface, Sun Chao, Sun Liang, He Dengke, Tian Siqing Aug 2020

Study On The Effect Of Dual-Freedom Coupling Between The Tilt Geophones And The Surface, Sun Chao, Sun Liang, He Dengke, Tian Siqing

Coal Geology & Exploration

In the process of coalfield seismic data acquisition, there is a situation of repeated geophone layout at the same point. The tilt angle difference of the geophones will leads the change of coupling condition between the geophone and the surface, which affects the quality of seismic data acquisition. In this paper, the tilt angle parameters of geophone were introduced into the coupling system of the geophone and the surface. From the point of view of vibration mechanics, the "vibration system with coupling of the dual degree of freedom" of tilt geophone was deduced. The influences of the tilt angle of …

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The High-Resolution Transient Electromagnetic Detection Technology For Ultra-Shallow Layer In Coal Mine, Zhang Jun Aug 2020

The High-Resolution Transient Electromagnetic Detection Technology For Ultra-Shallow Layer In Coal Mine, Zhang Jun

Coal Geology & Exploration

In order to reduce the blind zone of the transient electromagnetic detection in mines and improve the detection accuracy, the high-resolution transient electromagnetic detection technology for the ultra shallow layer in mines is studied. The high-resolution transient electromagnetic detection technology for ultra-shallow layer in mines is not only suitable for conventional mine geological exploration, but also for high-resolution detection of shallow geological bodies such as cracks in the roof of the mine roadway, ensuring the safe and efficient mining. Through theoretical research, the feasibility of the shallow high-resolution transient electromagnetic method in mine was established; the hardware system of the …

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Experimental Study On The Frequency Dispersion Response Of Composite Electrical Properties Of Coal, Meng Hui, Li Jian, Lei Dongji, Wang Yajuan Aug 2020

Experimental Study On The Frequency Dispersion Response Of Composite Electrical Properties Of Coal, Meng Hui, Li Jian, Lei Dongji, Wang Yajuan

Coal Geology & Exploration

In order to study the characteristics of frequency dispersion response of the composite electrical properties of coal, the real part R and imaginary part X of the composite resistance of coal body at different direction in different measured areas were measured, the frequency dispersion characteristics were analyzed, different classical models were used to conduct data inversion and comparison. The results show that the composite electrical property parameters(absolute value of R and X) of coal are inversely proportional to the measured area, the characteristic frequency points are not offset, the X-frequency divergence decreases with the increase of measurement area; …

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Research Status And Prospect Of Drill Pipe Thread Used In Coal Mine, Tian Dongzhuang, Chen Yanyu, Li Qing, Dong Mengmeng, Mou Peiying Aug 2020

Research Status And Prospect Of Drill Pipe Thread Used In Coal Mine, Tian Dongzhuang, Chen Yanyu, Li Qing, Dong Mengmeng, Mou Peiying

Coal Geology & Exploration

Drill pipe is one of the main device for drilling construction of gas drainage, water detection and drainage and geological exploration. Due to complicated force conditions and using environment of drill pipe, accidents in boreholes caused by the failure of drill pipe threads are common. According to different structural classification, the characteristics of drill pipe thread structure in coal mines are introduced in detail; the current research status of thread stress distribution and failure analysis of thread are summarized. The research methods of thread stress distribution mainly include analytical method, finite element method and test method. The main causes of …

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Design Of Piezoelectric Effect-Based Energy Recovery Device Wile Drilling, Wu Tianyu, Zheng Jun, Zhang Bo, Chen Yu, Tian Hong, Dou Bin Aug 2020

Design Of Piezoelectric Effect-Based Energy Recovery Device Wile Drilling, Wu Tianyu, Zheng Jun, Zhang Bo, Chen Yu, Tian Hong, Dou Bin

Coal Geology & Exploration

Aiming at the problem of continuous power supply of downhole instruments and the recovery of longitudinal vibration energy of drill pipe in drilling field, a new type of energy recovery device based on positive piezoelectric effect was designed. The radial dimension parameters and piezoelectric materials were designed by field experiences and geological survey reports. The piezoelectric coupling model was established based on the numerical simulation software COMSOL Multiphysics, and the length range and the best installation position of the piezoelectric plate were obtained through forced vibration analysis. Through modal analysis and frequency response research, it is obtained that the natural …

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Effect Of Calcination Time On The Physicochemical Properties And Photocatalytic Performance Of Carbon And Nitrogen Co-Doped Tio2 Nanoparticles, Emile Salomon Massima Mouele, Mihaela Dinu, Franscious Cummings, Ojo O. Fatoba, Myo Tay Zar Myint, Htet Htet Kyaw, Anca C. Parau, Alina Vladescu, M. Grazia Francesconi, Sara Pescetelli, Aldo Di Carlo, Antonio Agresti, Mohammed Al-Abri, Sergey Dobretsov, Mariana Braic, Leslie F. Petrik Aug 2020

Effect Of Calcination Time On The Physicochemical Properties And Photocatalytic Performance Of Carbon And Nitrogen Co-Doped Tio2 Nanoparticles, Emile Salomon Massima Mouele, Mihaela Dinu, Franscious Cummings, Ojo O. Fatoba, Myo Tay Zar Myint, Htet Htet Kyaw, Anca C. Parau, Alina Vladescu, M. Grazia Francesconi, Sara Pescetelli, Aldo Di Carlo, Antonio Agresti, Mohammed Al-Abri, Sergey Dobretsov, Mariana Braic, Leslie F. Petrik

Mining Engineering Faculty Research & Creative Works

The application of highly active nano catalysts in advanced oxidation processes (AOPs) improves the production of non-selective hydroxyl radicals and co-oxidants for complete remediation of polluted water. This study focused on the synthesis and characterization of a highly active visible light C–N-co-doped TiO2 nano catalyst that we prepared via the sol-gel method and pyrolyzed at 350 °C for 105 min in an inert atmosphere to prevent combustion of carbon moieties. Then we prolonged the pyrolysis holding time to 120 and 135 min and studied the effect of these changes on the crystal structure, particle size and morphology, electronic properties and …

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A Mechanism Of Electric Charge Losses In Adiabatically Compressed Ferroelectrics, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase Jul 2020

A Mechanism Of Electric Charge Losses In Adiabatically Compressed Ferroelectrics, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase

Mining Engineering Faculty Research & Creative Works

A ferroelectric depolarized by high strain-rates induced by the passage of adiabatic shock waves releases a high-density electric charge, initiating the generation of high voltage and megawatt power levels. Additionally, this depolarization process alters physical and mechanical properties that might cause energy and electric charge losses in the ferroelectric materials. We report, herein, the results of an experimental study of electric charge losses in Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 and Pb0.99(Zr0.52Ti0.48)0.99Nb0.01O3 ferroelectrics subjected to shock compression. We found that electric charge losses mainly occur in the compressed zone of ferroelectric elements, i.e., shock compression is an essential part of the charge loss mechanism. Based …

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Mining The Borderlands: Industry, Capital, And The Emergence Of Engineers In The Southwest Territories, 1855-1910. Grossman, Sarah E.M. University Of Nevada Press, 2018, James Altman Jun 2020

Mining The Borderlands: Industry, Capital, And The Emergence Of Engineers In The Southwest Territories, 1855-1910. Grossman, Sarah E.M. University Of Nevada Press, 2018, James Altman

Executive Vice President & Provost Faculty Research

In Mining the Borderlands: Industry, Capital, and the Emergence of Engineers in the Southwest Territories, 1855‐1910, distinguished scholar Sarah E.M. Grossman examines the early history of commercial mining along the US‐Mexico border. She brings to the task her extensive knowledge of the region, and a forensic detective's thirst for the truth. Her mission is to understand precisely how much, and in what specific ways, various commercial mining ventures in the desert Southwest contributed not only to the economic development of the region, but also to improvements in mining techniques, engineering methods, equipment, efficiency, working conditions, mining education, and most importantly, …

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Regional Distribution And Geotectonic Control Of Late Permian Tectonically Deformed Coal In Zhina Coalfield, Zhou Peiming, Gao Wei, Deng Lan, Fu Wei Jun 2020

Regional Distribution And Geotectonic Control Of Late Permian Tectonically Deformed Coal In Zhina Coalfield, Zhou Peiming, Gao Wei, Deng Lan, Fu Wei

Coal Geology & Exploration

In order to find out the tectonically deformed coal distribution law of Zhina coalfield, by sorting out and analyzing the data of more than 200 coal-bearing structural units including Bide syncline, Santang syncline, Zhuzang syncline, Arcong syncline and Guanzhai syncline in Zhina coalfield, Guizhou Province, combined with logging curve analysis, the regional distribution characteristics of coal body structure and structural control factors of No.6, No.16 and No.27 main coal seams are comprehensively analyzed. The study shows that from the west to the east, the proportion of tectonically deformed coal in Zhina coalfield increases gradually. The coal in the western part …

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Surface Efficient Gas Extraction Mode Based On Full Coverage Of Working Face, Fang Jiawei, Han Baoshan, Zhou Jiajia, Wang Zhengxi, Zhang Dingliang, Liu Jia, Xu Jianjun Jun 2020

Surface Efficient Gas Extraction Mode Based On Full Coverage Of Working Face, Fang Jiawei, Han Baoshan, Zhou Jiajia, Wang Zhengxi, Zhang Dingliang, Liu Jia, Xu Jianjun

Coal Geology & Exploration

Aiming at the problems of soft and broken coal seam, low permeability, difficulty in gas extraction and low drainage efficiency in working face, a full-coverage mode for gas extraction in working face through the horizontal well group with staged fracturing roof at both ends is proposed. Taking a mine in Suxian mining area of Huaibei coalfield as an example, based on the characteristics of in-situ stress and working face distribution, combined with the analysis of gas geological conditions and coal seam mechanical properties in the area, the cross section dipole sonic logging method was used to optimize the orientation of …

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Fractal Theory-Based Seepage Model Of Hershel-Bulkley Fluid In Porous Medium, Yang Xian, Lu Wei, Jin Xin, Chen Juan, Feng Xingfa Jun 2020

Fractal Theory-Based Seepage Model Of Hershel-Bulkley Fluid In Porous Medium, Yang Xian, Lu Wei, Jin Xin, Chen Juan, Feng Xingfa

Coal Geology & Exploration

Slurry is a kind of widely-used engineering fluid. Slurry will seeps into the formation in the process of construction, which has a certain impact on the project. In order to make deeper study on the seepage mechanism of slurry, the formation is simulated as porous medium, the slurry is simulated as Hershel-Bulkley fluid which can more comprehensively reflect its rheological properties, and the seepage model of Hershel-Bulkley fluid in porous medium was established based on Fractal theory. Based on the calculation results of seepage model, the effect of pressure gradient, flow index, consistency coefficient and porosity on the instantaneous average …

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Development Characteristics Of Water Conducted Fracture Zone Based On Overburden Structural Effect, Cao Zubao, Wang Qingtao Jun 2020

Development Characteristics Of Water Conducted Fracture Zone Based On Overburden Structural Effect, Cao Zubao, Wang Qingtao

Coal Geology & Exploration

In order to study the roof water disaster caused by coal mining in Huanglong coalfield, taking mining failure of layered overburden as research object, four typical composite structural models for coal-soft rock-hard rock-soft rock-hard rock(combination I), coal-soft rock-soft rock-hard rock-hard rock(combination Ⅱ), coal-hard rock-soft rock-hard rock-soft rock(combination Ⅲ) and coal-hard rock-hard rock-soft rock-soft rock(combination IV) were generalized. Numerical simulation and theoretical calculation were used to analyze the mining failure characteristics of different overburden combinations and correlation between water conducting fissures and lithologic combination structure of overburden. The law of the effect of overburden structure on the development height of water …

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The Law Of Soaking Infiltration And Collapse Deformation In Typical Loess-Paleosol Series, Zhao Jingang, Lyu Yuanqiang, Chao Jun, Yang Zhe, Xia Meng Jun 2020

The Law Of Soaking Infiltration And Collapse Deformation In Typical Loess-Paleosol Series, Zhao Jingang, Lyu Yuanqiang, Chao Jun, Yang Zhe, Xia Meng

Coal Geology & Exploration

In order to investigate the law of moisture migration and collapse deformation of the typical loess-paleosol series, on the basis of water immersion test of the large test pits of Xi’an North-airport intercity rail transit in the loess tableland of Weibei, the real-time in-site observation was adopted, the soaking infiltration and collapse deformation of collapsible soil layer under conditions of non water seepage hole were traced and tested. The results show that: The movement of water immersion is dominated by vertical movement in the early stage. The whole form is like a continuous increase of “weight” shape. As the water …

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Numerical Calculation Of Temperature Field Of Freeze-Sealing Pipe Roof Method In Gongbei Tunnel, Long Wei, Rong Chuanxin, Duan Yin, Guo Ke Jun 2020

Numerical Calculation Of Temperature Field Of Freeze-Sealing Pipe Roof Method In Gongbei Tunnel, Long Wei, Rong Chuanxin, Duan Yin, Guo Ke

Coal Geology & Exploration

This paper took the Gongbei tunnel in the Zhuhai Connection Section of the Hong Kong-Zhuhai-Macao Bridge as an example to study the development of the temperature field of the Freeze-Sealing Pipe Roof Method. Based on the heat transfer theory of two-dimensional porous media, the FEM software COMSOL was used to numerically analyze the actual working conditions of the active freezing period, the numerical calculation was verified by field measurement. The development and distribution of the temperature field before and after the opening of the special-shaped freezing pipes was studied. The results showed that: when freezing for 30 days, the concrete …

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Influence Of Parting In Composite Coal Seam On Interpretation Of Fault Throw By Channel Wave Seismic Exploration, Su Xiaoyun Jun 2020

Influence Of Parting In Composite Coal Seam On Interpretation Of Fault Throw By Channel Wave Seismic Exploration, Su Xiaoyun

Coal Geology & Exploration

The channel wave seismic exploration technology has achieved relatively reliable result in detection of faults, collapse columns and the change of coal thickness in working faces, now becomes the preferred method for detection of underground geological structures. But for detection of geological structures in partings of composite coal seams the method has still certain problems. In order to study the influence of partings in composite coal seams on detection of channel wave seismic exploration, various models were built by changing thickness, lithology of parting in composite coal seams and experimenting with channel wave seismic detection in Shanxi to study how …

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Suppression Of Multiple Reflected Refraction In Shallow Low-Velocity Zones By Vertical Combination Of Seismic Sources, Fu Yanning, Chang Suoliang, Zhang Sheng, Liu Zuiliang, Yang Yong, Chen Qiang, Liu Bo, Xu Yuying Jun 2020

Suppression Of Multiple Reflected Refraction In Shallow Low-Velocity Zones By Vertical Combination Of Seismic Sources, Fu Yanning, Chang Suoliang, Zhang Sheng, Liu Zuiliang, Yang Yong, Chen Qiang, Liu Bo, Xu Yuying

Coal Geology & Exploration

A special type of multiple reflected refraction often appears in seismic records in areas with low-velocity structures. It seriously affects the closed reflection wave, which causes the distortion of the reflection wave shape and affects the correct interpretation of the seismic data. Based on the forward simulation of the multiple reflected refraction equation, the generation mechanism of multiple reflected refraction in the shallow low-velocity zones was set forth. A method of suppressing multiple reflected refraction by vertically combined dual sources was proposed. The formation parameters(formation thickness and velocity)are obtained according to the methods of small refraction and micro logging in …

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Seismic Impedance Inversion Of Coal Field With Reflectivity Method Based On Bayesian Theory, Yang Zhen, Gao Zhenyu, Liu Xingye Jun 2020

Seismic Impedance Inversion Of Coal Field With Reflectivity Method Based On Bayesian Theory, Yang Zhen, Gao Zhenyu, Liu Xingye

Coal Geology & Exploration

Seismic inversion can reflect the morphology of subsurface formation and facies information more intuitively. Seismic impedance inversion can directly produce elastic information of underground media, providing reliable information for subsequent coal identification, water channel prediction and collapse column distinguishing. A Bayesian-based inversion of reflectivity method was developed. It can consider the various propagation effects of seismic waves and solve the objective function nonlinearly, which can more accurately calculate the impedance and improve the inversion resolution. The method is applied to the actual data from Buertai coal mine and satisfactory results are output, which effectively verifies the feasibility and effectiveness of …

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Research On Electronically Controlled Automation Technology Of Underground Drilling Rig For Coal Mine, Dong Hongbo, Yao Ningping, Ma Bin, Liao Jiangnan Jun 2020

Research On Electronically Controlled Automation Technology Of Underground Drilling Rig For Coal Mine, Dong Hongbo, Yao Ningping, Ma Bin, Liao Jiangnan

Coal Geology & Exploration

In order to conform to the development direction of automation and intelligence of underground equipment in coal mines, a set of electronically controlled system of drilling rig has been developed according to the characteristics of underground drilling rigs in coal mines. The functions such as remote control, parameter monitoring, working condition judgment and safe interlocking were realized in the drilling rig. On the basis of single-acting control of the drilling rig, the technology of automatic drilling and automatic trip-out of the drilling rig was studied, which greatly improved the automation of underground drilling rig in coal mine. The functional experiments …

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Design And Numerical Simulation Of Multi-Layer Bit With Extra-High Matrix, Sun Qibin, Shen Lina, Yang Gansheng, Tian Guoliang, Ruan Hailong, Chen Xi Jun 2020

Design And Numerical Simulation Of Multi-Layer Bit With Extra-High Matrix, Sun Qibin, Shen Lina, Yang Gansheng, Tian Guoliang, Ruan Hailong, Chen Xi

Coal Geology & Exploration

Aiming at the problem that the life of the diamond bit is limited by the height of the bit matrix, an optimized design scheme of an impregnated diamond bit with extra-high multi-layer matrix was proposed. In the design of the bit, eccentric staggered cutting teeth, alternate waterways and water baffles were introduced to ensure the cooling and effective drilling of the bit. Through strength and hydraulic flow field simulation, the strength of the drill bit was checked, the rationality of the waterway structure was verified, and the finished product of the drill bit was further realized. The drill bit breaks …

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Analysis Of Paleoclimatic Cycles In The Ultra Thick Coal Seam Of Yan'an Formation In The Southern Ordos Basin, Dong Guoqi, Wang Dongdong, Liu Haiyan, Mao Qiang, Yin Lusheng Jun 2020

Analysis Of Paleoclimatic Cycles In The Ultra Thick Coal Seam Of Yan'an Formation In The Southern Ordos Basin, Dong Guoqi, Wang Dongdong, Liu Haiyan, Mao Qiang, Yin Lusheng

Coal Geology & Exploration

Coal is a climate-sensitive sediment that contains abundant paleoclimate information. In order to find out the paleoclimate information contained in the coal seam and the evolution of its controlling factors, the No.4 thick coal seam in the first member of Yan’an Formation in the south of Ordos basin was studied. Based on the intensive sampling of the thick coal seam, the information of organic macerals, major and trace elements, and stable carbon isotopes of organic matter were systematically tested. By using the macerals, characteristic elements and carbon isotopes of coal and rocks, four cycles of paleoclimate with alternation of warm-wet …

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Change Law Of Adsorption/Desorption Energy Of Coal With Different Water Content Under The Action Of Far Infrared, Ma Kai, Ma Qianqian, Shi Yongtao Jun 2020

Change Law Of Adsorption/Desorption Energy Of Coal With Different Water Content Under The Action Of Far Infrared, Ma Kai, Ma Qianqian, Shi Yongtao

Coal Geology & Exploration

The essence of coal gas adsorption/desorption process is the process of interaction between gas molecules and molecules or atoms on the surface of the coal matrix, and the nature of the interaction is energy change. In order to deeply study the coalbed gas adsorption/desorption rules and energy change rules under the action of far infrared, the self-developed device was used to perform CO2 adsorption/desorption experiments on coal samples with different water contents under the action of far infrared. Then, the experimental results are calculated using the adsorption/desorption energy change model obtained from the principle of far-infrared thermal radiation, and …

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Model-Driven Energy Attenuation Method For Coal Seam Strong Reflection, Zhang Xianxu Jun 2020

Model-Driven Energy Attenuation Method For Coal Seam Strong Reflection, Zhang Xianxu

Coal Geology & Exploration

The reflection of coal seam in seismic data has the characteristics of strong energy, which makes the reflection of adjacent strata often concealed by the reflection of coal seam. This makes it difficult to image the adjacent weak layer and lithological interpretation difficult. Aiming at this problem, a model-driven energy attenuation method for coal seam strong reflection was proposed. This method uses the coal thickness calculated by logging and measured by borehole in underground coal mine to construct cross plot with reflection amplitude of coal seam, and fit the relationship formula between amplitude and thickness. The digital model was constructed …

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Influence Of Water Injection In Burst-Prone Coal Seam On Suction And Sticking During Drilling, Hao Zhiyong, Li Zhiwei, Pan Yishan Jun 2020

Influence Of Water Injection In Burst-Prone Coal Seam On Suction And Sticking During Drilling, Hao Zhiyong, Li Zhiwei, Pan Yishan

Coal Geology & Exploration

When the spiral drill pipe is used to predict and evaluate the dynamic disasters such as rock burst, the drilling dynamic phenomena such as suction and sticking are easy to occur. In order to study the influence of water injection in burst-prone coal seam on suction and sticking, the mechanism of dynamic phenomenon of suction and sticking was analyzed by establishing the mechanical model of drill pipe, pointing out that the stress of coal body and the amount of drilling cuttings are the important factors that affect the occurrence of suction and sticking, deriving the calculation formula of drilling mechanical …

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Table Of Contents, The Editors Jun 2020

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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Production Decline Law And Influencing Factors Of High-Rank Coal Cbm Wells, Jia Huimin, Hu Qiujia, Mao Jianwei,, Mao Chonghao, Liu Chunchun, Zhang Qing, Liu Changping Jun 2020

Production Decline Law And Influencing Factors Of High-Rank Coal Cbm Wells, Jia Huimin, Hu Qiujia, Mao Jianwei,, Mao Chonghao, Liu Chunchun, Zhang Qing, Liu Changping

Coal Geology & Exploration

In order to reveal the production decline law of high-rank coal CBM wells, based on the development data of Fanzhuang block in southern Qinshui basin for more than 10 years, this paper studies the decline point, decline type and influencing factors of high-rank coal CBM wells by means of numerical simulation and statistical analysis. The results show that the decline point of the Fanzhuang block is 25% and the average decline point of the single well is 21%. Most wells begin to decline after drainage of 4 years. The decline point of CBM well is determined by matrix permeability and …

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Fracturing Parameters Analysis And Productivity Evaluation Of Vertical Coalbed Methane Wells With Nitrogen Foam, Li Hengle, Cao Yunxing, Zhou Dan, Chai Xuezhou, Liu Tongji, Feng Peiwen, Shi Bin, Tian Lin Jun 2020

Fracturing Parameters Analysis And Productivity Evaluation Of Vertical Coalbed Methane Wells With Nitrogen Foam, Li Hengle, Cao Yunxing, Zhou Dan, Chai Xuezhou, Liu Tongji, Feng Peiwen, Shi Bin, Tian Lin

Coal Geology & Exploration

Fracturing parameters are important parameters that affect the fracturing effect, fracture characteristics and CBM productivity. Through an in-depth understanding of the influence of fracturing parameters on productivity, it is essential to optimize the fracturing process and increase the productivity of CBM wells. Taking 45 nitrogen foam fracturing wells in Lu’an mining area as the research object, the types of fracturing operation curves and their effects on productivity were studied. The relationship between fracturing fluid dosage and productivity was discussed. The differences in productivity of nitrogen foam wells and hydraulic fracturing wells was compared and analyzed. The results show that: Nitrogen …

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