Oil, Gas, and Energy Commons^™

A Study Of The Frustrated Honeycomb Battery Material Na2ni2teo6, Nathan Christopher Episcopo

Open Access Theses & Dissertations

The P2-type layered hexagonal compound Na2Ni2TeO6 with Ni2+ on a honeycomb lattice was synthesized by the standard solid-state route. Structural characterization chemical phase purity was confirmed by Rietveld refinement of laboratory and synchrotron data. The crystal structure refines well in the P63/mcm space group. Single crystal growth trials using the self-flux-melt method were conducted with limited success. The magnetic transition temperature pertaining to Ni2+ lattice was confirmed by analysis of specific heat capacity to be . The magnetic susceptibility remains largely unchanged in magnetic field of and external pressure of . There is an almost linear response in isothermal magnetization …

Dynamic Analysis Of A Microgrid Powered With An Inverter And Machine-Based Distributed Resources, Brandon William Blackstone

UNLV Theses, Dissertations, Professional Papers, and Capstones

The proliferation of renewable distributed energy resources, particularly photovoltaic (PV) power systems, and the increasing need for a reliable power supply has led to the concept of microgrids, a mini-grid that consists of locally connected power generation units and needs, able to operate connected or disconnected from the utility grid, using controlled and coordinated methods to provide for the users of the microgrid the best possible conditions for their needs. The main technical issues facing microgrids include some of the following, seamless transition from stand-alone to utility grid connected operation, how to preserve frequency and voltage stability, and provide the …

Investigative Study Of Microalgal And Electrochemical Wastewater Treatment Systems And Modeling Of The Wafer-Enhanced Electrodeionization Using Supervised Learning, Humeyra Betul Ulusoy Erol

Graduate Theses and Dissertations

Wastewater has a serious impact on environment and public health due to its high concentration of nutrients and toxic contaminants. Without proper treatment, excess nutrients discharged in wastewater can cause a damage to the ecosystem such as undesirable pH shifts, cyanotoxin production, and low dissolved oxygen concentrations.

Main objectives of this dissertation work were to investigate i) the biofuel potential of P. cruentum when grown in swine wastewater, ii) the influence of four most commonly used ion exchange resins on the system efficiency and selectivity for the removal of sodium, calcium, and magnesium ions, and iii) the modeling of wafer-enhanced …

Prediction Of Coal Seam Gas Content Based On Abc-Bp Model, Zang Zijing, Wu Haibo, Zhang Pingsong, Dong Shouhua

Coal Geology & Exploration

It is valuable to exploit the coalbed-methane which is rich in our country. The prediction of gas content in coalbed methane reservoir is a key step in the early stage of development and utilization. In recent years, BP neural network algorithm has been often used in coalbed methane prediction, but the model has some shortcomings in the training process, such as slow convergence speed, sensitive to initial value and easy to fall into local minimum value. Therefore, this paper proposed an improved BP neural network prediction model characterized by artificial bee colony algorithm. Firstly, R-type cluster analysis was used to …

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 …

Fracture Feature Recognition Of Sandstone After High Temperature Based On Ra/Af, Ge Zhenlong, Sun Qiang, Wang Miaomiao, Zhao Chunhu

Coal Geology & Exploration

It is of great significance to carry out the research on rock high temperature damage information identification for geothermal development and underground coal gasification. Based on the changes of acoustic emission parameters RA and AF in the failure process of sandstone after different high temperature treatments, the development and evolution law of different types of cracks in sandstone after high temperature treatment are studied. The results show that tensile cracks are dominant in the whole loading process of sandstone. When the loading stress exceeds 80% of the peak stress, the proportion of shear cracks increases rapidly, which can be regarded …

Vegetation Disturbance Analysis In Coal Mining Area With High Ground Water Level Based On Landsat Time Series Ndvi Data, Fang Liangcheng, Chen Yongchun, An Shikai, Xu Yanfei, Yin Mengjie, Li Zhihui, Zhao Ping, Chen Yeyu

Coal Geology & Exploration

The eastern mining area of China is an important coal and grain composite production area. Due to the flat terrain and high underground diving level, most of the subsidence caused by mining is perennial or seasonal water, which causes serious land, ecological and environmental problems. As an important part of the ecological environment in mining area, vegetation has dynamic characteristics due to the external disturbance and the change of environmental factors. The normalized difference vegetation index(NDVI) is a common indicator for remote sensing monitoring of vegetation growth. The analysis based on NDVI time series data can effectively reveal the disturbance …

Research On The Grouting And Setting Pressure Of The Automatic Hole Sealing Device In Underground Coal Mine, Li Chengcheng, Wang Yi, Wang Li, Duan Huijun

Coal Geology & Exploration

Grouting pressure and setting pressure are the main parameters for designing an automatic hole sealing device in coal mine, and they are also the important basis for the design of automatic hole sealing construction. Based on the radial sealing range of the slurry, the paper analyzes the sealing effect under different slurry pressure conditions by means of theoretical calculation and numerical simulation. Combined with the mechanical characteristics of the rubber Mooney-Rivlin model, extrusion seal and other principles, the optimal injection pressure and setting pressure are studied and determined. The results show that the radial sealing range of the slurry at …

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 …

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 …

Long-Term Heat Transfer Performance Of Underground Coaxial Heat Exchanger For Medium-Deep Geothermal, Li Fengcui, Han Ershuai, Liang Lei, Wu Jing'an, Lu Bingxue

Coal Geology & Exploration

Underground coaxial heat exchanger(UCHE) for medium-deep geothermal has the characteristic of the high heat transfer capacity and outlet water temperature, so it has attracted great attention in the heating industry. However, the current research mainly focus on the heat transfer performance of the UCHE during a single heating period, with insufficient analysis on the long-term heat transfer performance. In this paper, considering the operation characteristics of heat supply in heating season and stopping working in non-heating season for underground coaxial heat exchanger for medium-deep geothermal, a numerical heat transfer model is proposed based on the energy conservation equation. The numerical …

Development Of Deep Geothermal Energy And Its Influence On Geothermal Water Flow Field: Taking The Development Of Deep Geothermal Energy In Lankao County For An Example, Song Qianjin, Wang Gang, Xu Yichuan, Cheng Lei

Coal Geology & Exploration

In order to study the influence of deep geothermal energy development on the flow field of thermal reservoir, deep geothermal energy development in Lankao County is selected as the research object. The geological structure and regional structure of the study area since Cenozoic are analyzed, and the of geothermal exploitation and existing problems in the area are investigated. According to the types of geothermal energy, the characteristics of the Quaternary(Q), Neogene Minghuazhen Formation(N₂) and Neogene Guantao Formation(N₁) are analyzed. The conditions of fault distribution, thermal reservoir development and water-resisting boundary in the area are found out …

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 …

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 …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Progress Of Coal Fines Agglomeration And Settlement Mechanism Based On High Efficiency Coalbed Methane Drainage, Li Yong, Han Wenlong, Wang Yanbin, Meng Shangzhi, Wu Xiang, Wang Zhuangsen, Ma Zhentao, Liu Du, Zhao Shihu

Coal Geology & Exploration

Significant low-yield and inefficient wells seriously hinder the development of China’s coalbed methane (CBM) industry, and the coal fractures and production pipes blocking caused by the coal fines settlement are the key influencing factors. This paper systematically investigates the latest research progress in the composition, generation mechanism, suspension transport and output control of coal fines produced by coalbed methane wells at home and abroad, summarizes the control mechanism and key issues of coal fines agglomeration-settlement and dispersion behavior, and proposes research prospects. The coal fines problem accompanies the entire process of CBM exploration and development, involving all aspects of geological …

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; …

Optimization On Particle Size Fraction Of Lightweight Coated Ceramsite Proppant In Coal Reservoir, Chang Xiaoliang, Lyu Runsheng, Wang Peng, Li Bing, Gao Lin

Coal Geology & Exploration

Hydraulic fracturing is currently one of the main technical measures for enhancing coal reservoirs permeability. The spreading range and transportation distance of proppants in the fracture is an important indicator of hydraulic fracturing to evaluate fracturing effect. According to the characteristics of coal reservoirs in Lu’an mining area, physical experiments and numerical simulation methods are used to compare and analyze the effects of fracture conductivity, sand spreading range, particle size combination and other factors on conductivity of coalbed methane wells, and the best proppants particle size and particle size ratio are selected. The research results indicate that the fracture conductivity …

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 …

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 …

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. …

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 …

New Mathematical Model And Key Parameters Of Capillary Pressure Curves Of High-Rank Coal Samples, Chen Ke, Tang Lei, Yin Chao, He Wei, Zhang Wei, Quan Zheng

Coal Geology & Exploration

Capillary pressure is an important parameter that affects the occurrence and development of coalbed methane. In order to establish an effective mathematical model to characterize capillary pressure curves of high-rank coalbed methane reservoirs, coal samples from No.3 coal seam in southern Qinshui Basin was taken as the research object, high-pressure mercury intrusion experiments were carried out, and the adaptability of the typical mathematical models of the capillary pressure curve currently in common use are systematically evaluated. Then a new mathematical model with higher fitting degree for high-rank coal is established. The results show that capillary pressure curves of 6 coal …

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 …

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 …

Multi-Level Fuzzy Mathematics-Based Comprehensive Evaluation Model Of Cbm Well Productivity, Feng Yulong, Zhou Linyuan, Wang Qian, Liu Chengrui

Coal Geology & Exploration

To accurately predict the productivity of CBM wells, a multi-level fuzzy mathematics method was used to establish a comprehensive evaluation model including 3 secondary evaluation parameters(i.e. resource conditions, development conditions, and transformation processes) and 10 tertiary evaluation parameters. Combined with the data of reservoir parameters and stimulation technologies of 15 coalbed methane target blocks in China, the comprehensive evaluation work was carried out using the model. Finally, the actual production of each block was collected to verify the evaluation results, and the corresponding relationship between the evaluation results and the production was obtained. The results show that, the average daily …

Geochemical Characteristics And Genesis Of Coalbed Methane In Baode Area, Li Yangbing, Zeng Lei, Hu Weiqiang, Chen Xin, Ma Litao, Liu Cheng, Huang Ying, Qiao Fang

Coal Geology & Exploration

In order to find out the geochemical characteristics and origins of coalbed methane(CBM)in Baode area, coal, CBM and water samples were collected, gas component analysis, quality detection of CBM well-produced water and stable isotope analysis were carried out. The results show that CH₄ is the main hydrocarbon gas in CBM composition and its volume fraction ranges from 88.60% to 97.59%; a small amount of ethane is contained, and the volume fraction is only 0.01%-0.14%. The drying coefficient is greater than 0.99, the CBM belongs to the extremely dry CBM. The non-hydrocarbon components mainly contain CO₂ and N_{2 …}

Characteristics Of Shale Gas Reservoir In Upper Paleozoic Coal Measures In Yangquan Block, Qinshui Basin, Li Yangyang, Li Xianqing, Zhang Xueqing, Xiao Xianming, Yu Zhenfeng, Wang Baoyu

Coal Geology & Exploration

Shale reservoir characteristics are the basic content of shale gas storage capacity evaluation. In order to explore the properties of high-evolved coal-measures shale gas reservoirs and optimize favorable reservoirs, various experimental methods of rock pyrolysis, X-ray diffraction, scanning electron microscopy, high-pressure mercury intrusion, low-temperature N₂ and CO₂ gas adsorption were applied to the Qinshui Basin. Reservoir characteristics were studied with core samples of coal-measure shale core from the Upper Paleozoic in Yangquan Block. The results show that the Upper Paleozoic coal-measures shale in Yangquan Block of the Qinshui Basin has a high content of organic carbon(average TOC is …

Study On Mesozoic Magmatic Intrusion And Paleozoic Multi-Mineral Genesis Mechanism In Huanghebei Coalfield，Shandong Province, Wang Huaihong, Shen Lijun, Wang Dongdong, Zhu Yuzhen, Li Zengxue, Wang Yongjun, Mao Qiang

Coal Geology & Exploration

Accumulation of various minerals is common in strata, especially in areas invaded by magma, which is more conducive to the generation and preservation of various minerals and greatly improves the exploration benefit and development value of mineral resources. Taking Huanghebei Coalfield in Shandong Province as an example, this paper studies the genesis mechanism of Mesozoic rock intrusion and Paleozoic multiple minerals(coal, coal-bed methane, coal-measure shale gas and rich iron ore). Research shows that: Huanghebei Coalfield Carboniferous-Permian Period tectonic conditions and sedimentary environment are conducive to the development of coal seam, and coal seam distribution in the plane is characterized by …

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 …