Estimation Method And Application Of Free Gas Content In Coal,
2019
Xi'an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi'an 710077, China
Estimation Method And Application Of Free Gas Content In Coal, Jiang Wenping, Zhang Qun, Zhang Peihe, Dong Mintao, Tian Xinjuan, Ru Ting
Coal Geology & Exploration
In order to study the distribution characteristics of free gas content in coal reservoirs, based on the understanding that free gas mainly exists in coal pores, the estimation method of free gas content is optimized. Based on the test data of coalbed methane arameters of 42 groups of coals with different ranks from lignite to anthracite in typical coal-bearing areas of China, the free gas content of different coal samples were calculated by using the optimized method of free gas content estimation, and compared with the results of desorption gas content. The results show that the ratio of free gas …
Development And Test Of Self-Adjusting Deflected Wellhead Sealing Device For Coalbed Methane Wells,
2019
Xi'an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi'an 710077, China
Development And Test Of Self-Adjusting Deflected Wellhead Sealing Device For Coalbed Methane Wells, Pang Tao
Coal Geology & Exploration
In order to solve the problem of fluid and gas leakage in coal seam gas well, a self-adjusting deflected wellhead sealing device suitable for coal seam gas wells is developed. The device consists of three parts:Smooth rod sealing box, self-adjusting deflected part and lower sub. The self-adjusting deflected part is a smart combination of universal joint and high pressure flexible rubber tube, which makes the sealing box and the polished rod always keep good concentricity. Practical application shows that this kind of polished rod sealing device has reliable sealing performance, simple structure and the prospect of popularization and application.
Evaluation Method Of Compressibility Of Shale Gas Reservoir In Consideration Of The Influence Of Fracture Toughness,
2019
State Key Laboratory of Coal Mine Disaster Dynamics and Control of Chongqing University, Chongqing 400044, China; State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam of Chongqing University, Chongqing 400044, China
Evaluation Method Of Compressibility Of Shale Gas Reservoir In Consideration Of The Influence Of Fracture Toughness, Zhang Chenqing, Xu Jiang, Peng Shoujian, Yan Fazhi, Wu Bin, Yue Yuqing
Coal Geology & Exploration
Compressibility is an important basis for measuring the response of shale gas reservoirs to hydraulic fracturing. Currently, the brittleness index commonly used for shale compressibility has been evaluated. However, in practice, there are problems in which the brittleness index is similar and the actual fracturing effect is far different. In order to make up for the lack of brittleness index for the evaluation of compressibility of shale gas reservoirs, this study incorporated critical mechanical energy release rate in consideration of the influence of fracture toughness, and defined the average critical mechanical energy release rate of the integrated modes I and …
Influence Of The Freezing-Thawing Cycles On Soil-Water Characteristics Of Soil In Open-Pit Mine Dumping Sites,
2019
College of Mining, Liaoning Technical University, Fuxin 123000, China
Influence Of The Freezing-Thawing Cycles On Soil-Water Characteristics Of Soil In Open-Pit Mine Dumping Sites, Wang Xuedong, Li Shiyu, Sun Yanfeng, Ye Guo
Coal Geology & Exploration
In order to study the unsaturated soil-water characteristics of soil under freezing-thawing cycles, the soil in Yuanbaoshan open-pit mine dumping site was selected as the research object. The variation of matrix suction and structure of soil under different water content after different freezing-thawing cycles was studied. The results show that during the same freezing-thawing cycles, the matrix suction increases with the decrease of water content, and the range increases gradually. The soil-water characteristic curve can be divided into sensitive stage, sub-sensitive stage and insensitive stage. With the increase of freezing-thawing cycles, the curvature of soil-water characteristic curve increases first and …
Influence Of Loading Rate On The Fracture Characteristics Of Large-Size Specimen,
2019
College of Geosciences and Surveying Engineering, China University of Mining and Technology(Beijing), Beijing 100083, China; State Key Laboratory of Mining Disaster Prevention and Control of Shandong University of Science and Technology, Qingdao 266590, China
Influence Of Loading Rate On The Fracture Characteristics Of Large-Size Specimen, Chen Juntao, Li Ming, Cheng Binbin, Yang Fan, Men Huili, Shao Zhujuan
Coal Geology & Exploration
According to the high mining speed of modern mines in China, the fracture characteristics of rock mass under different uniaxial loading rate was systematically analyzed. Based on the geological condition of deep rock mass in Jining area, the optimum mortar composed of 425 Portland cement, sand with particle size less than 2 mm, gypsum, water and high efficient water reducer was used, which had the mechanical properties similar to real rock mass was ascertained. Applying the triaxial rock test system of coupled stress-seepage and PCI-2 real-time monitoring system of AE, the fracture process of specimens of large size under biaxial …
A New Instability Criterion Of Double Strength Reduction Method For Slope,
2019
Geomatics and prospecting Engineering, Jilin Jianzhu University, Changchun 130118, China; School of Civil Engineering and Architecture, Northeast Electric Power University, Jilin 132012, China
A New Instability Criterion Of Double Strength Reduction Method For Slope, Fang Hongwei, Wu Jianxun, Hou Zhenkun
Coal Geology & Exploration
Based on the slip line field theory(SLFT), a new instability criterion of strength reduction method with double re-duction factors for homogeneous slopes was proposed. It is judged that the slope is in the limit equilibrium state when the slope contour under limit equilibrium state(abbreviated as the critical slope contour) calculated by the SLFT intersects with the slope line at the toe. The critical curve was constructed in the plane of the inverse of the double reduction factors, and the comprehensive safety factor was derived. The slope calculation results show that three relative position relationships between the initial point and the …
The Effect Of Viscoelasticity And Velocity Anisotropy On The Reflections Of A Thin Bed,
2019
Science&Technology Department, Sinopec, Beijing 100728, China
The Effect Of Viscoelasticity And Velocity Anisotropy On The Reflections Of A Thin Bed, Chen Benchi, Wang Chao, Chen Changxing, Shi Lei
Coal Geology & Exploration
The coal seam is a typical thin bed characterized by much lower elastic impedance than that of the surrounding rock. Coal seam has viscoelasticity and velocity anisotropy and its reflection amplitude changes with frequency. In order to analyze the effect of viscoelasticity and velocity anisotropy on seismic responses of a thin bed, this paper aims at a thin-bed model with strong impedance contrast and simulates seismic responses under three different assumptions, elastic and velocity isotropy, viscoelastic and velocity isotropy, and viscoelastic and velocity anisotropy, through numerical simulation method based on wave equations. Comparison of these seismic reflections shows that the …
Acquisition Platform Of Frequency Domain Ip Signal,
2019
Engineering Research Center of Advanced Mining Equipment, Ministry of Education, Hunan University of Science and Technology, Xiangtan 411201, China; Key Laboratory of Mine Deposits Research, Guilin University of Technology, Guilin 541004, China
Acquisition Platform Of Frequency Domain Ip Signal, Fu Guohong, Zhang Qianfeng, Cheng Hui, Xie Tiancai
Coal Geology & Exploration
In order to improve the versatility of the induced polarization(IP) signal receiver of traditional frequency domain, a signal acquisition platform was designed, which can acquire and process IP signals of frequency domain such as variable-frequency signals, dual-frequency IP signals, and pseudo-random multi-frequency IP signals and so on. Hardware circuits were established based on STM32 to execute low-pass filtering, program-controlled amplification, analog-to-digital conversion, and data communication. The host computer was developed in LabVIEW to achieve parameter settings, digital filtering, spectrum analysis, amplitude measurement and calculation to obtain target parameters such as PFE, and has waveform display and playback, data storage and …
Design And Application Of Multi-Section Bundled Bag Wire-Line Coring Drilling Tools,
2019
Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University), Ministry of Education, Changsha 410083, China; School of Geosciences and Info-Physics, Central South University, Changsha 410083, China
Design And Application Of Multi-Section Bundled Bag Wire-Line Coring Drilling Tools, Han Yi, Zhang Shaohe, Bai Rui, Sun Pinghe, Shu Biao, Cao Han, Zhang Xinxin
Coal Geology & Exploration
Because the existing conventional wire-line coring drilling tool lacks the water-proof and core-protecting device, the broken core is easily eroded when the core is drilled in a complicated layer such as loose, weak, broken layers and the core is easy to fall off during the lifting process, so that the coring rate and core quality are not up to the design requirements, and even core can not be taken to. In response to the above problems, a bag-type wire-line coring drilling tool was designed. The drill adds a multi-section bundled bag assembly structure to the conventional wire-line coring drilling tool …
Development Of Impact Screw Motor,
2019
Xi'an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi'an 710077, China
Development Of Impact Screw Motor, Wang Siyi, Li Quanxin, Liu Jianlin, Zhao Jiangpeng, Yang Dongdong
Coal Geology & Exploration
Aiming at the problems of low efficiency and high consumption of bits and drilling tools in drilling hard rock with conventional single bend screw motor, an impact screw motor is developed by adding an impact mechanism between the universal shaft of a common screw motor and the drill bit. The impact screw motor has dual functions of impact and orientation. The structure and the working principle of impact mechanism, the design of key components and the characteristics of the impact screw motor are introduced. Laboratory tests were carried out on the φ89 mm impact mechanism, and the peak impact …
Mining’S Impact On Environmental And Human Health: A Case Study Of Ramba County’S Gold Mine,
2019
SIT Study Abroad
Mining’S Impact On Environmental And Human Health: A Case Study Of Ramba County’S Gold Mine, Vivika Fernes
Independent Study Project (ISP) Collection
This research project aims to gain a greater understanding of the health implications that Ramba County’s goldmine has on miners, their families, and the environment. While this study observes the community-at-large, inclusive of visiting miners and extended family members of workers, it will focus on women who engage in artisanal and small-scale gold mining (ASGM). Millions of people in the developing word depend on ASGM for their livelihood, evident in this case study in Ramba County. However, while gold is associated with wealth, there is great irony in the fact that those working within the mining industry are being exploited …
Los Efectos De La Minería En La Salud: El Movimiento Social Aymara En Torno Al Cerro Márquez,
2019
SIT Study Abroad
Los Efectos De La Minería En La Salud: El Movimiento Social Aymara En Torno Al Cerro Márquez, Maya Hajny Fernandez
Independent Study Project (ISP) Collection
With the political and social state of Chile’s history, mining has been present for hundreds of years, affecting the land and the indigenous populations in the country. This study asked how mining in the town of Ticnamar would affect the community, what positive and negative results mining activity has, what the most important elements of the social movement against mining are and how all of these elements influence health. The study sought to learn and study the impact of and the motivations that mining could have in the community of Ticnamar, and how it is perceived by the community. More …
A New Discrete Wavelength Backscattered Ultraviolet Algorithm For Consistent Volcanic So2 Retrievals From Multiple Satellite Missions, Bradford L. Fisher, Nickolay A. Krotkov, Pawan K. Bhartia, Can Li, Simon Carn, Eric Hughes, Peter J. T. Leonard
Michigan Tech Publications, Part 1
This paper describes a new discrete wavelength algorithm developed for retrieving volcanic sulfur dioxide (SO2) vertical column density (VCD) from UV observing satellites. The Multi-Satellite SO2 algorithm (MS_SO2) simultaneously retrieves column densities of sulfur dioxide, ozone, and Lambertian effective reflectivity (LER) and its spectral dependence. It is used operationally to process measurements from the heritage Total Ozone Mapping Spectrometer (TOMS) onboard NASA's Nimbus-7 satellite (N7/TOMS: 1978–1993) and from the current Earth Polychromatic Imaging Camera (EPIC) onboard Deep Space Climate Observatory (DSCOVR: 2015–ongoing) from the Earth–Sun Lagrange (L1) orbit. Results from MS_SO2 algorithm for several volcanic cases were …
Volcano Monitoring From Space Using High-Cadence Planet Cubesat Images Applied To Fuego Volcano, Guatemala,
2019
Michigan Technological University
Volcano Monitoring From Space Using High-Cadence Planet Cubesat Images Applied To Fuego Volcano, Guatemala, Anna Aldeghi, Simon Carn, Rudiger Escobar-Wolf, Gianluca Groppelli
Michigan Tech Publications, Part 1
Fuego volcano (Guatemala) is one of the most active and hazardous volcanoes in the world. Its persistent activity generates lava flows, pyroclastic density currents (PDCs), and lahars that threaten the surrounding areas and produce frequent morphological change. Fuego’s eruption deposits are often rapidly eroded or remobilized by heavy rains and its constant activity and inaccessible terrain makes ground-based assessment of recent eruptive deposits very challenging. Earth-orbiting satellites can provide unique observations of volcanoes during eruptive activity, when ground-based techniques may be too hazardous, and also during inter-eruptive phases, but have typically been hindered by relatively low spatial and temporal resolution. …
Analysis Of An Updated Paleointensity Database (Qpi‐Pint) For 65–200 Ma: Implications For The Long‐Term History Of Dipole Moment Through The Mesozoic,
2019
University of Oslo
Analysis Of An Updated Paleointensity Database (Qpi‐Pint) For 65–200 Ma: Implications For The Long‐Term History Of Dipole Moment Through The Mesozoic, E. V. Kulakov, C. J. Sprain, P. V. Doubrovine, A. V. Smirnov, G. A. Paterson, L. Hawkins, L. Fairchild, E. J. Piispa, A. J. Biggin
Michigan Tech Publications, Part 1
The global paleointensity database for 65–200 Ma was analyzed using a modified suite of paleointensity quality criteria (QPI) such that the likely reliability of measurements is assessed objectively and as consistently as possible across the diverse data set. This interval was chosen because of dramatic extremes of geomagnetic polarity reversal frequency ranging from greater than 10 reversals per million years in the Jurassic hyperactivity period (155–171 Ma) to effectively zero during the Cretaceous Normal Superchron (CNS; 84–126 Ma). Various attempts to establish a relationship between the strength of Earth's magnetic field and the reversal frequency have been made …
Evaluation Of A 38 L Explosive Chamber For Testing Coal Dust Explosibility,
2019
Missouri University of Science and Technology
Evaluation Of A 38 L Explosive Chamber For Testing Coal Dust Explosibility, Robert Eades, Kyle A. Perry
Mining Engineering Faculty Research & Creative Works
Coal dust explosions are the deadliest disasters facing the coal mining industry. Research has been conducted globally on this topic for decades. The first explosibility tests in the United States were performed by the Bureau of Mines using a 20 L chamber. This serves as the basis for all standardized tests used for combustible dusts. The purpose of this paper is to investigate the use of a new 38 L chamber for testing coal dust explosions. The 38 L chamber features design modifications to model the unique conditions present in an underground coal mine when compared to other industries where …
A Novel Method Of Using Iron Nanoparticles From Coal Fly Ash Or Ferric Chloride For Acid Mine Drainage Remediation,
2019
Missouri University of Science and Technology
A Novel Method Of Using Iron Nanoparticles From Coal Fly Ash Or Ferric Chloride For Acid Mine Drainage Remediation, Crisanda Gilbert, Olushola S. Ayanda, Olanrewaju O. Fatoba, Godfrey Madzivire, Leslie F. Petrik
Mining Engineering Faculty Research & Creative Works
Iron nanoparticles (nano Fe) were extracted from coal fly ash (CFA) or ferric chloride (FeCl3) and used for acid mine drainage (AMD) remediation. Characterization was achieved by X-ray diffraction (XRD), X-ray fluorescence, scanning electron microscopy-energy dispersive spectroscopy (SEM–EDX), high resolution transmission electron microscopy (HRTEM), and the Braunaer–Emmet–Teller (BET) surface area determination. The HRTEM indicated good dispersion of the characteristic bead-like structure of nano Fe. It was also observed that the nano Fe were mainly in the zero-valent oxidation state, as denoted by the characteristic peak at ≈ 44.7° in the XRD analysis; it was accompanied by the generally accepted oxide …
Effect Of Nmr Technology-Based Ultrasonic Frequency On Stimulated Cracking Of Coal,
2019
School of Safety Engineering, China University of Mining & Technology, Xuzhou 221116, China National; Engineering Research Center for Coal Mine Gas Control, Xuzhou 221116, China
Effect Of Nmr Technology-Based Ultrasonic Frequency On Stimulated Cracking Of Coal, Ma Huiteng, Zhai Cheng, Xu Jizhao, Sun Yong
Coal Geology & Exploration
In order to further study the effect of ultrasonic frequency on the stimulated cracking effect of coal, the paper conducted the crack experiment on the original coal samples by using the ultrasonic generation meter, and measured the coal by using the NMR equipment through analyzing the T2 curve, the changes of pore structure before and after coal sample cracking were deeply studied. The results show that the pore structure of coal can be effectively improved by the ultrasonic wave. After the crack induced by the ultrasonic wave, the pore quantity inside the coal increased and the total porosity, effective …
Advances On Geological-Geochemical Research Of Coal-Type Uranium In China,
2019
Institute of Earth Resources and Geosciences, China University of Mining and Technology, Xuzhou 221116, China
Advances On Geological-Geochemical Research Of Coal-Type Uranium In China, Zhou Xianqing, Qin Yong, Lu Lu
Coal Geology & Exploration
There is a huge gap in uranium resources in China. Only developing traditional uranium resources is unable to meet the increasing demand in energy and national defense construction. The exploitation and utilization of coal-type uranium resources can relieve the pressure of demand for uranium resources to a certain extent. By summarizing the research results of coal-type uranium in recent years, the ore location, uranium content range, formation time and distribution range of coal-bearing strata of major coal-type uranium deposits in China, and the definition criteria of coal-type uranium are given, which provides a basis for the classification of coal-type uranium …
Structural Optimization And Simulation Analysis Of High Reliability Wire-Line Coring Drilling Tools For Submarine Drilling Rigs,
2019
National Local Joint Engineering Laboratory of Marine Mineral Resources Exploration Equipment and Safety Technol-ogy, Hunan University of Science and Technology, Xiangtan 411201, China; School of Mechanical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China
Structural Optimization And Simulation Analysis Of High Reliability Wire-Line Coring Drilling Tools For Submarine Drilling Rigs, Wang Jialiang, Peng Fenfei, Wan Buyan, Zhou Yun
Coal Geology & Exploration
In order to improve the working reliability of wire-line coring drilling tools used in submarine drilling rigs, based on the particularity of submarine environment, from the aspect of improvement of the single action performance of the single action mechanism and the working reliability of the suspension mechanism, the structural optimization of the single action mechanism was carried out, the numerical simulation analysis of the suspension mechanism was conducted by using ABAQUS simulation. The results show that the improved bearing assembly structure can restrain sea water corrosion, improve the centering effect of arbor and enhance the flexibility of bearing assembly. The …
