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Articles 211 - 240 of 247
Full-Text Articles in Engineering
The Research Progress And Work Prospect Of Special Purpose Coal, Qiao Junwei, Ning Shuzheng, Qin Yunhu, Zhang Ning, Li Congcong, Zhang Jianqiang, Wei Yingchun, Zhu Shifei, Zhu Kaijia
The Research Progress And Work Prospect Of Special Purpose Coal, Qiao Junwei, Ning Shuzheng, Qin Yunhu, Zhang Ning, Li Congcong, Zhang Jianqiang, Wei Yingchun, Zhu Shifei, Zhu Kaijia
Coal Geology & Exploration
Based on the refined geological exploration of coal, the clean and efficient use of coal, this paper reviews the implications of scarce coal and special purpose coal in previous studies. It was pointed out that special purpose coal is based on clean and efficient use of coal for coal resources with special industrial applications. The main types of coal are liquefaction coal, gasification purpose coal, coking coal and special high-element coal. Based on the coal quality evaluation of coal and the use of coal graded quality, this paper has sorted out the key evaluation indicators and evaluation parameters of special …
Adsorbability Of Shale In Coal Measures And Its Influencing Factors, Zhang Baoxin, Fu Xuehai, Zhang Qinghui, Zhou Baoyan, Liu Zheng
Adsorbability Of Shale In Coal Measures And Its Influencing Factors, Zhang Baoxin, Fu Xuehai, Zhang Qinghui, Zhou Baoyan, Liu Zheng
Coal Geology & Exploration
In order to reveal the adsorption and gas-bearing characteristics of shale in coal measures, this study was based on the gas content, isotherm adsorption, high-pressure mercury injection, and liquid nitrogen adsorption of more than 200 coal shale in six major coal fields in Shanxi Province and Junggar basin. XRD diffraction and other measured data, the adsorption and gas characteristics of shale were analyzed, and the influencing factors were discussed. The results show that the measured gas content of shale is between 0-5.87 cm3/g, concentrated at 0.90-2.00 cm3/g; VL is between 0.11-6.3 cm3/g with …
Distribution Characteristics Of Associated Elements In Middle Jurassic Coal In The North Of Datong Coalfield And Their Geological Significance, Qu Xiaorong
Coal Geology & Exploration
In order to study the geochemical characteristics and geological significance of associated elements in Middle Jurassic coal of Datong coalfield, the distribution and occurrence of the associated elements in 9 coal seams in the northern Datong coalfield were analyzed by inductively coupled plasma mass spectrometry(ICP-MS), X-ray diffraction(XRD), optical electron microscopy and scanning electron microscopy(SEM). The results show that the Jurassic coal in Datong coalfield has low trace element content, and beneficial elements(Li, Ga) are far lower than the boundary grade, which has no development potential. But the harmful elements such as Co and Zn in No.2 coal, Tl in No.9, …
Storage Rule And Controlling Factors Of Coalbed Gas In Zhaoguan Mine Field Of Huanghebei Coalfiled, Song Xiaozhong
Storage Rule And Controlling Factors Of Coalbed Gas In Zhaoguan Mine Field Of Huanghebei Coalfiled, Song Xiaozhong
Coal Geology & Exploration
Storage rule and controlling factors of coalbed gas in Zhaoguan mine field were analyzed on the basis of the generation, storage and migration theory of coalbed gas in combination with the data of geological exploration and mine production. From research on the regional geological evolution, coal generating and storing capacity and lithologic characteristics, geological structure, burial depth, bedrock thickness, hydrogeological conditions and magmatic intrusion, it was found that underground hydrodynamic conditions and magmatic intrusion events are the controlling factors of coalbed gas storage in the mine. Underground hydrodynamic conditions had obvious effect, shallow hydrodynamic conditions were manifested mainly as migration …
Slope Stability Evaluation Based On Set Pair Cloud Model, Yao Jianye, Zhang Shan, Hao Guoqiang
Slope Stability Evaluation Based On Set Pair Cloud Model, Yao Jianye, Zhang Shan, Hao Guoqiang
Coal Geology & Exploration
When the set pair analysis is applied to evaluate slope stability, the connection degree is usually decided by linear function, which can't reflect the actual conditions of the engineering project objectively and comprehensively and neglect the system randomness. The set pair analysis theory is improved by application of cloud theory which is superior in dealing with the connection degree and set pair analysis-cloud model of slope stability evaluation is established. In this model, the weight matrix is obtained by using the cloud theory to improve the AHP, and the evaluation matrix is obtained by combining with the connection degree evaluation …
Microseismic Positioning Method Based On Differential Evolution Algorithm, Wang Yunhong, Wang Baoli, Duan Jianhua
Microseismic Positioning Method Based On Differential Evolution Algorithm, Wang Yunhong, Wang Baoli, Duan Jianhua
Coal Geology & Exploration
Aiming at the problem that the location accuracy of conventional time-based microseismic location method depends on the accuracy of travel time, a differential evolution microseismic location method is proposed to improve the locating target function. Based on the traditional micro-seismic P-wave travel-time location method, the error weighting coefficient was added to the localization objective function, which reduced the impact of the first-time picking accuracy on the microseismic location by reducing the effect of the microseismic signal path with low initial pick-up accuracy on the locating error. The differential evolution algorithm, through population initialization, mutation, crossover, and selection operations, solves the …
Development And Application Of Geocoal For In-Seam Seismic Data Processing, Wang Baoli, Jin Dan
Development And Application Of Geocoal For In-Seam Seismic Data Processing, Wang Baoli, Jin Dan
Coal Geology & Exploration
A data processing platform for in-seam seismic exploration(ISS) was developed, which can make ISS better serve safe production in coal mines. The software design architecture was constructed, and the function modules and the software running environment are introduced. Finally, some software interfaces and results were demonstrated.
Analysis Of Influencing Parameters Of Temperature Field In A New Pipe-Roofing Freezing Method, Wu Yuwei, Li Chunfang, Hu Jun, Wang Zhixin, Wang Shucheng
Analysis Of Influencing Parameters Of Temperature Field In A New Pipe-Roofing Freezing Method, Wu Yuwei, Li Chunfang, Hu Jun, Wang Zhixin, Wang Shucheng
Coal Geology & Exploration
The development status of the temperature field around the freezing pipe in the method of pipe roofing freezing is the technical focus of this construction method. In order to study the development of the temperature field in this method, two paths are selected in the model, and analysis points are placed on the path. By analyzing the effects of soil thermal conductivity, volumetric heat capacity, latent heat of phase change, and original ground temperature on the development law of the temperature field, the following conclusion was drawn:Compared with the method of freezing the pipe curtain of the Gongbei tunnel in …
Table Of Contents, The Editors
Present Situation And Prospect Of Drilling Equipment Technology In Coal Mine, Yao Ke, Tian Hongliang, Yao Ningping, Yin Xinsheng, Fang Peng, Yao Yafeng, Wu Di, Wang Longpeng
Present Situation And Prospect Of Drilling Equipment Technology In Coal Mine, Yao Ke, Tian Hongliang, Yao Ningping, Yin Xinsheng, Fang Peng, Yao Yafeng, Wu Di, Wang Longpeng
Coal Geology & Exploration
After over 40 years of development, the technology of underground drilling equipment, vital to guarantee safety and efficient production for coal mines, has been improved greatly. Combining with the characteristics of products, types of technology and application domains, the development of domestic and foreign of underground drilling equipment for coal mines are introduced, the application effects and existing problems of drilling machines are analyzed, especially the development experience and current situation of domestic drilling machines are summarized, detailing on technology status of the five most representative models, such as the split type drill, caterpillar drill, electro-hydraulic control drill, rubber wheel …
Coupling Relationship Between Oil And Gas Of Mesozoic Coal-Bearing Measures And Uranium Metallogenesis In Huangling Area, Si Qinghong, Cao Huifeng, Li Jianguo, Sima Xianzhang, Yu Reng‘An, Liu Houning, Liu Xiaoxue, Zhang Chao
Coupling Relationship Between Oil And Gas Of Mesozoic Coal-Bearing Measures And Uranium Metallogenesis In Huangling Area, Si Qinghong, Cao Huifeng, Li Jianguo, Sima Xianzhang, Yu Reng‘An, Liu Houning, Liu Xiaoxue, Zhang Chao
Coal Geology & Exploration
In order to clarify the coupling relationship between oil and gas of Mesozoic coal-bearing measures(reservoir) and uranium deposits(points) in Huangling area, field geology investigations of boreholes and sections, analysis and processing of borehole data and experimental data, and integration of reservoir and uranium(point) information were carried out. Collation and systematic study of tectonic-sedimentary systems of Mesozoic coal-bearing mesure, uranium geological characteristics, oil and gas geology characteristics, spatial distribution relationship between hydrocarbon reservoirs and uranium deposits, genetic relationship between hydrocarbon-bearing fluids and uranium-associated altered minerals, and the time relationship between hydrocarbons and uranium mineralization were discussed. The study shows that the …
Design And Implementation Of Information Management Platform For Big Data Of Uranium, Zhou Xiaoxi, Deng Fan, Wan Lin, Yang Jun
Design And Implementation Of Information Management Platform For Big Data Of Uranium, Zhou Xiaoxi, Deng Fan, Wan Lin, Yang Jun
Coal Geology & Exploration
In order to integrate the borehole data and geological survey data of sandstone-type uranium deposits, the unified management of the borehole database was implemented, and the efficiency of integrated application of the geological data of borehole data was improved. A comprehensive information management platform for uranium was designed and implemented. For big data platform, the four-layer framework composed of the base installation, information resources, application service, user interaction was proposed. Techniques such as virtualization of cloud computing, distributive storage and parallel computing were adopted to set up the basic environment of the big data of uranium and improve the unified …
Uranium Metallogenic Characteristics And Prospecting Significance Of Hongqingliang Area In Northeastern Ordos Basin, Wu Zhaojian, Yan Maohua, Han Xiaozhong, Yu Reng’An, Sima Xianzhang, Jiang Zhe, Yin Dongfa, Hu Hang, Deng Yutao
Uranium Metallogenic Characteristics And Prospecting Significance Of Hongqingliang Area In Northeastern Ordos Basin, Wu Zhaojian, Yan Maohua, Han Xiaozhong, Yu Reng’An, Sima Xianzhang, Jiang Zhe, Yin Dongfa, Hu Hang, Deng Yutao
Coal Geology & Exploration
A NNW trending uranium metallogenic belt was found in the northeastern Ordos basin in last 20 years. In order to evaluate further the mineralizing potential of the middle part of this uranium minerogenetic belt, we choose a typical less developed area:Hongqingliang area as a research object to analyze its ore-forming conditions on the basis of the secondary development of coalfield data. These ore-forming conditions are composed of characteristics of stratigraphic structure, sand thickness distribution, spatial morphology of roof and floor, the sedimentary-tectonic evolution of Zhiluo Formation and so on. After comprehensive analysis of uranium mineralization law and ore controlling factors, …
Lithology Characteristics And Meaning Of The Target Layer Of Sandstone-Type Uranium Deposits In Kamusite Area Of The Eastern Junggar Basin, Yin Dongfa, Han Xiaozhong, Huang Pengtao, Sima Xianzhang, Yu Reng’An, Zhou Yu, Wu Zhaojian, Hu Hang, Chen Lulu
Lithology Characteristics And Meaning Of The Target Layer Of Sandstone-Type Uranium Deposits In Kamusite Area Of The Eastern Junggar Basin, Yin Dongfa, Han Xiaozhong, Huang Pengtao, Sima Xianzhang, Yu Reng’An, Zhou Yu, Wu Zhaojian, Hu Hang, Chen Lulu
Coal Geology & Exploration
Junggar basin is an important energy exploration base in China. The exploration of its uranium resources has been difficult to break through. By secondary development of the coal exploration results of Kamusite area in eastern Junggar basin, further drilling verification, industrial uranium orebodies have been found. The Middle Jurassic Toutunhe Formation is the ore-bearing target in this area, has very good prospecting prospect and research significance. In order to understand the petrological characteristics and uranium mineralization of the target-layer sand body in this area, through the detailed field geological survey, borehole observation and other methods, with the advanced analysis and …
Technology And Practice For Deep Cbm Fracturing In Eastern Ordos Basin, Wang Xuxing, Wang Xingzun, Guo Bumin, Yuan Zheng, Feng Qing
Technology And Practice For Deep Cbm Fracturing In Eastern Ordos Basin, Wang Xuxing, Wang Xingzun, Guo Bumin, Yuan Zheng, Feng Qing
Coal Geology & Exploration
The resources of deep coalbed methane buried at depth of more than 1 200 m in the eastern Ordos basin are rich and the key point for further exploration and development of CBM in the future. Compared with shallow CBM fracturing, there are many challenges in deep CBM fracturing such as with high situ stress, high closure stress, breakdown pressure as well as complex mechanical parameters of rock. Combined with the existing practice of CBM fracturing, taking the deep CBM buried at depth of about 2 000 m in the eastern Ordos basin as an example, tubing+ circulating SSD +packer …
Response Relation Between Fracturing Curve And Reservoir Pollution Degree Of Coalbed Methane Wells, Zhuang Dengdeng, Wang Yanbin, Tao Chuanqi, Chen Yan
Response Relation Between Fracturing Curve And Reservoir Pollution Degree Of Coalbed Methane Wells, Zhuang Dengdeng, Wang Yanbin, Tao Chuanqi, Chen Yan
Coal Geology & Exploration
In order to study the relationship between response curve and the pollution degree of fractured reservoir, taking Shizhuang block in Qinshui basin as an example, wells with different sensitivity of reservoir in the block were selected, through comparison of the difference of the dropping trace characteristics after the hydraulic curve reaches the fracture pressure in the fracturing curves of fracturing operation in different wells, the response law of hydraulic dropping trace and the reservoir sensitivity was summed up. Then in the same block according to the dropping trace of the hydraulic curves, the sensibility of reservoir was judged in several …
Method And Application Of Diagnosis Of Low Productivity Damage Of Cbm Wells, Feng Qing
Method And Application Of Diagnosis Of Low Productivity Damage Of Cbm Wells, Feng Qing
Coal Geology & Exploration
Coal reservoirs differ from conventional reservoirs, are easily damaged and the damage factors are complex. Massive papers focus on CBM damage mechanism, but fewer studies on pollution types and stimulating measures. This paper studied various factors influencing CBM and water production in a block of Qinshui basin from angle of geology, engineering and drainage, and established the typical production curve model to determine reservoir judgement method of damage types of low production wells, layer and well selection standards for reservoir with big yield-increasing potential to carry out second reconstruction. The results proved that factors influencing CBM wells productivity such as …
Surface Free Energy Of Shale Gas In Niutitang Formation In Guizhou Province, Li Xijian, Yin Xin, Li Weiwei, Liu Shangping, Zhang Pei
Surface Free Energy Of Shale Gas In Niutitang Formation In Guizhou Province, Li Xijian, Yin Xin, Li Weiwei, Liu Shangping, Zhang Pei
Coal Geology & Exploration
In order to study the adsorption mechanism of shale for gas, the isothermal adsorption experiments on shale samples from wells Fengcan 1 and Tianma 1 in Guizhou Province were carried out at 50℃, 60℃, 80℃, and the isothermal adsorption curves of CH4 and CO2 were plotted, the shale surface free energy was calculated and the adsorption characteristics of CH4 and CO2 from shale were analyzed by the surface free energy. The results show that when the temperature is constant, the surface free energy of shale gas increases with the increase of pressure, and the change of …
Integrated Identification Of Sequence Boundary Through Outcrop, Seismic With Logging And Geochemistry: A Case Of Jurassic In Northeastern Margin Of Ordos Basin, Zhang Tianfu, Zhang Yun, Cheng Yinhang, Miao Peisen, Ao Cong, Jin Ruoshi, Duan Lianfeng, Duan Xiaolong
Integrated Identification Of Sequence Boundary Through Outcrop, Seismic With Logging And Geochemistry: A Case Of Jurassic In Northeastern Margin Of Ordos Basin, Zhang Tianfu, Zhang Yun, Cheng Yinhang, Miao Peisen, Ao Cong, Jin Ruoshi, Duan Lianfeng, Duan Xiaolong
Coal Geology & Exploration
Jurassic strata is mainly rock series containing coal and uranium in Ordos basin. The recognition of Jurassic sequence interfaces were mainly relied on the field outcrop, logging lithology of unconformity surface or the sedimentary discontinuity. However, it is tend to experience human recognition of randomness in the sequence interfaces recognition without macroscopic characteristics. Therefore, based on routine identification work such as outcrop profile and electrical curve of nearly 1 000 boreholes, combined with vertical changes of two-dimensional seismic profile and chemical index of alteration(CIA), three long-term cycle sequence interfaces(TSB1-TSB3) and seven medium-term cycle sequence interfaces(SB1-SB7) were finally identified in Jurassic …
Elastic Mechanics Solution Of Water Proof Key Layer In Coal Seam Floor Under High Water Pressure, Wang Yan, Yao Duoxi, Lu Haifeng
Elastic Mechanics Solution Of Water Proof Key Layer In Coal Seam Floor Under High Water Pressure, Wang Yan, Yao Duoxi, Lu Haifeng
Coal Geology & Exploration
Aiming at the problem of water resisting capacity of the key layer in seam floor under the action of high pressure water, the key stratum was simplified as a fixed beam. The stress and displacement were calculated by the stress function method and the semi inverse method respectively. The results of two calculations were compared with the FLAC3D results. The results show that the stress and displacement obtained by the stress function method are more appropriate than those calculated by the FLAC3D method. It is suggested that for elastic mechanics analytic method of the fixed beam of the …
Application Of Fuzzy Mathematics In Selecting The Favorable Location Of Shale Gas Survey Well: Taking Northwest Guizhou As An Example, Lin Lamei, Zhang Jinchuan
Application Of Fuzzy Mathematics In Selecting The Favorable Location Of Shale Gas Survey Well: Taking Northwest Guizhou As An Example, Lin Lamei, Zhang Jinchuan
Coal Geology & Exploration
Exploration and development of shale gas in China is now in the early-middle stage. Drilling geological survey well is an important mean to obtain data and discover shale gas in the blank area of Lower Paleozoic shale data in south China. However, due to the extremely complex structure and geomorphic conditions in these areas, it is very difficult to optimize the location of wells. Taking northwest Guizhou as an example, based on a large number of field geological survey work, the evaluation criteria of geological and engineering geological conditions for shale gas survey well location are put forward. In the …
Multi-Source Spatial Information Fusion-Based Water Abundance Zoning Of The Composite Layer Of Water-Bearing Seam Roof, Zhou Zhenfang, Dong Yang, Dong Xingling, Li Peng, Wang Qiangmin, Qiao Wei, Zhao Chunhu, Yang Jian
Multi-Source Spatial Information Fusion-Based Water Abundance Zoning Of The Composite Layer Of Water-Bearing Seam Roof, Zhou Zhenfang, Dong Yang, Dong Xingling, Li Peng, Wang Qiangmin, Qiao Wei, Zhao Chunhu, Yang Jian
Coal Geology & Exploration
Coal mining in Jurassic coalfield is generally threatened by roof water. The composite sandstone of No.2 coal seam in Yuandatan coal mine located at North Shaanxi was selected as research object, and the development height of water-conducting fracture zone was calculated using the empirical formula and measurement formula respectively, based on the calculated results, it was determined that the range for water abundance zoning was from the No.2 coal seam to the top boundary of Zhiluo Formation. According to the previous studies, we selected seven factors such as the equivalent thickness of sandstone, the property of interbed of sandstone and …
Application Of Improved Hierarchic Analytic Process In The Classification Of Mine Hydrogeological Types, Wang Tiantian, Jin Dewu, Yang Jian, Liang Xiangyang
Application Of Improved Hierarchic Analytic Process In The Classification Of Mine Hydrogeological Types, Wang Tiantian, Jin Dewu, Yang Jian, Liang Xiangyang
Coal Geology & Exploration
The classification of mine hydrogeological type is an important part of mine hydrogeology work. It is of great significance to analyze water filling conditions, evaluate water hazard and guide mine water prevention work. In order to evaluate mine hydrogeological conditions, this paper introduced optimal transfer matrix to improve hierarchic analytic process, and then applied this method to classify mine hydrogeological types. Taking four pairs of active mines in Hujierte mining area of Inner Mongolia as an example, the evaluation index system for classification of mine hydrogeological types was built on the basis of analysis of the hydrogeological conditions, then theoretical …
Analysis On The Development Characteristics And Influencing Factors Of Gas Pores In Coal, Zhang Hui, Wu Jing, Yuan Liying, Song Xiaozhong, Lin Bowei
Analysis On The Development Characteristics And Influencing Factors Of Gas Pores In Coal, Zhang Hui, Wu Jing, Yuan Liying, Song Xiaozhong, Lin Bowei
Coal Geology & Exploration
Based on the study of coalfield geology and coal petrology, using field emission scanning electron microscopy(FESEM) as the main observation method, nanoscale pore research on coals was carried out for different regions, different geological ages and different metamorphic degrees. The results show that gas pores in coal are the pores left by coalbed methane(gas) generation, accumulation and escape during coal metamorphism, are secondary porosity. The pore diameter is mainly at nanometer size and round shape, with uneven density and distribution. The gas pore is intensive, often forms gas pore group, gas pore zone and gas pore nest. The gas pore …
Analysis On Water Burst Characteristics During United Mining Of Multiple Coal Seams In Binchang Mining Area, Wu Mouda
Coal Geology & Exploration
Aiming at the abnormal water inrush in working face of united mining of multiple coal seams in Binchang mining area, the relationship between gushing water and formation characteristics, geological structure and ground pressure were analyzed based on the characteristics of water inrush. The causes of abnormal water inrush were discussed from the aspects of water source, water-conducting channels and water inrush mechanism. The analysis shows that Luohe Formation has become the direct or indirect aquifer for coal mining under the influence of mining intensity and formation factors of Anding Formation; the formation with large dip generated by the fold structure …
Risk Judgment Technology Of Water Accumulation In Overlying Goaf Based On Plate Shell And Fracture Mechanics Theory, Ti Zhengyi, Zhang Feng, Qin Hongyan, Zhu Zhijie
Risk Judgment Technology Of Water Accumulation In Overlying Goaf Based On Plate Shell And Fracture Mechanics Theory, Ti Zhengyi, Zhang Feng, Qin Hongyan, Zhu Zhijie
Coal Geology & Exploration
In order to avoid the threat of water penetration from the goaf of overlying seam No.6 during mining seam No.10 in Shengli coal mine of Linfen, Shanxi, plate-shells theory and fracture mechanics theory were used to establish the mechanics model of the development height of water-conducting fissure zone and the rupture depth of the floor. The water conducting fissure zone developmental height in districts I-VI of coal seam 10 is 46.77 m, 48.86 m, 56.05 m, 56.14 m, 56.33 m and 55.20 m, and the rupture zone depth of the floor in districts I-IV areas of coal seam 6 is …
Test On The Strength Of The Backfill Fine Sand Mixture Composed Of Cement-Fly Ash-Cinder, Wen Liang, Yan Changhong, Zhang Zheng, Xu Baotian, Zhang Shunjing, Zhang Dongping, Zhou Yinkang
Test On The Strength Of The Backfill Fine Sand Mixture Composed Of Cement-Fly Ash-Cinder, Wen Liang, Yan Changhong, Zhang Zheng, Xu Baotian, Zhang Shunjing, Zhang Dongping, Zhou Yinkang
Coal Geology & Exploration
By using orthogonal test to analyze the influence of cement content, fly ash content and cinder content, the non-confining compression strength test was carried out for the stability of large-scale landfill base structure and for the saving costs. The strength at different curing ages was analyzed by variance, and the reinforcement mechanism was also studied. The test results showed that the optimal ratio of cement stabilized soil under different factors is 20% of cement, 15% of fly ash, 10% of cinder, and the strength is the largest at this point. And the influence of cement content on the strength of …
Acoustic Emission Test Of Calcareous Sands Under Undrained Condition, Yang Chao, Wang Kai, Qiao Liping, Meng Qingshan, Wang Ren
Acoustic Emission Test Of Calcareous Sands Under Undrained Condition, Yang Chao, Wang Kai, Qiao Liping, Meng Qingshan, Wang Ren
Coal Geology & Exploration
Calcareous sand acoustic emission was tested under undrained condition to study the law of acoustic emission with different confining pressure, shear rate, initial void ratio and grading. The results showed that when the confining pressure was lower than 400 kPa, calcareous sand acoustic emission event rate increased with confining pressure. But when the confining pressure was increased to 800 kPa, calcareous sand acoustic emission event rate decreased. The test of calcareous sand was divided into particle breakage stage and particle slip stage in low shear rate. Two stages can't be distinguished clearly as the shear rate increases. Loose and dense …
Random Noise Attenuation By Eemd In Common Offset Gathers, Shi Zhanzhan, Xia Yanqing, Zhou Huailai, Chi Yuelong, Pang Su
Random Noise Attenuation By Eemd In Common Offset Gathers, Shi Zhanzhan, Xia Yanqing, Zhou Huailai, Chi Yuelong, Pang Su
Coal Geology & Exploration
There are two problems in the random noise attenuation in f-x domain:(1) Reflected waves as hyperbolic events in pre-stack CMP gather or shot gathers, de-noising will damage the effective wave; (2) Seismic signals are complex non-stationary signals, requiring that the de-noising method has the adaptivity. Aiming at these two problems, a random noise suppression method based on f-x EEMD was proposed. The method utilizes the reflected waves which are horizontal events in common offset gathers, satisfying the f-x domain de-noising assumption, and the good adaptability of EEMD algorithm to non-stationary signals. For each frequency …
Analysis On Influence Of Ground Transmitting Electrode On Bidirectional Em-Mwd Signal Transmission Based On Ansys, Shao Chun, Han Jian, Chu Zhiwei, Xu Lin
Analysis On Influence Of Ground Transmitting Electrode On Bidirectional Em-Mwd Signal Transmission Based On Ansys, Shao Chun, Han Jian, Chu Zhiwei, Xu Lin
Coal Geology & Exploration
The grounded emitter electrode is a necessary component of the bidirectional EM-MWD signal downlink system, and its reasonable parameter setting can improve the signal downlink effect, but at present, little is known about its influence on the downlink signal. This paper is based on the bi-directional EM-MWD working mechanism, combined with the current field theory, using ANSYS finite element software, establishes a three-dimensional simulation model of bidirectional EM-MWD signals, and analyzes the emission distance, length, diameter and resistivity of the ground transmitting electrode versus the downlink signal. The simulation results show that the downlink signal reception effect is positively correlated …