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Full-Text Articles in Engineering

Numerical Analysis On Csw Fracturing Behavior Of Coal Seam Under Constraint Of Geological And Engineering Conditions, Qin Yong, Li Hengle, Zhang Yongmin, Zhao Youzhi, Zhao Jincheng, Qiu Aici Feb 2021

Numerical Analysis On Csw Fracturing Behavior Of Coal Seam Under Constraint Of Geological And Engineering Conditions, Qin Yong, Li Hengle, Zhang Yongmin, Zhao Youzhi, Zhao Jincheng, Qiu Aici

Coal Geology & Exploration

As a revolutionary technology for rock stratum reformation, the controllable shock wave(CSW) fracturing technology has achieved remarkable effect in coal seam reconstruction, and application exploration in the field of coal safety mining has been carried out. However, the previous understanding of the basic CWS fracturing rules under the constraints of geological engineering factors is insufficient due to the limitation of experimental and field monitoring conditions, which restricts the exploration of the fracturing mechanism and the optimization of the field operation parameters. In view of this, based on the description of CSW coal seam reformation and its engineering scientific problems, the …


Study On Density Of The Supercritical Methane, Zhang Xinbin, Song Dangyu, Li Yunbo, Qi Yong'an, Fan Shunli Feb 2021

Study On Density Of The Supercritical Methane, Zhang Xinbin, Song Dangyu, Li Yunbo, Qi Yong'an, Fan Shunli

Coal Geology & Exploration

The density of supercritical methane is not only an important parameter for calculation of unconventional natural gas resources and adsorption capacity of methane in coal, but also a main indicator for measurement of the diffusion efficiency of supercritical methane and the ability to dissolve organic matter. Through analysis and comparison of the applicability of various gas state equations, it is realized that the Helmholtz energy state equation can accurately calculate the density of methane under the conditions of 0-30 MPa and 270-360 K. A calculation program for methane density was written using Microsoft Office Excel, and the error was less …


Effects Of Alternating Stress On Casing Damage Mechanism, An Fengchen, Zhang Feiyang, Yi Hao, Zhang Sui'an Feb 2021

Effects Of Alternating Stress On Casing Damage Mechanism, An Fengchen, Zhang Feiyang, Yi Hao, Zhang Sui'an

Coal Geology & Exploration

Horizontal well staged fracturing technology of horizontal well has been widely used in the exploitation of low-permeability oil and gas reservoirs and coalbed methane, and has achieved good economic results. However, the vertical section of the casing is found to be damaged with serious deformation in the process of multi-stage hydraulic fracturing, which will prevent bridge plugs from being installed at the preferred design depths, thereby resulting in abandonment of all remaining fracturing stages. In this study, a user element is developed to simulate the mechanical behavior at the casing-cement sheath interface under cyclic loads. The developed element is then …


Micro-Pore Structure And Fractal Characteristics Of Terrestrial Shales: A Case Study Of Shahezi Formation In Xujiaweizi Fault Depression, Lin Zizhi, Lu Shuangfang, Chang Xiangchun, Li Junqian, Zhang Pengfei, Zhou Nengwu, Zhang Yu, Wang Junjie, Huang Hongsheng Feb 2021

Micro-Pore Structure And Fractal Characteristics Of Terrestrial Shales: A Case Study Of Shahezi Formation In Xujiaweizi Fault Depression, Lin Zizhi, Lu Shuangfang, Chang Xiangchun, Li Junqian, Zhang Pengfei, Zhou Nengwu, Zhang Yu, Wang Junjie, Huang Hongsheng

Coal Geology & Exploration

The pore structure and fractal characteristics of shale are analyzed, and their impacting factors are also revealed using the low temperature nitrogen adsorption-desorption method, combined with scanning electron microscopy, C-S analysis and XRD. The results showed that the mineral compositions of Shahezi Formation continental shales were dominated by clay minerals, quartz and feldspar. The pore types in shales were mainly clay mineral intragranular pores, feldspar dissolution pores and grain edge pore, while the organic pores were not developed. The adsorption isotherms of shales belonged to the type Ⅳ isotherm according to the IUPAC, which develop two types of hysteresis loop, …


Framework On Intelligent Decision Support System For Coal Seam Floor Water Hazard Prevention And Control, Jin Dewu, Li Peng Feb 2021

Framework On Intelligent Decision Support System For Coal Seam Floor Water Hazard Prevention And Control, Jin Dewu, Li Peng

Coal Geology & Exploration

Coal floor water inrush is a common type of water disaster in the production process of coal mines in North China coalfield. In order to solve the scientific decision making problem of water hazard prevention and control engineering and further improve the reliability of the relevant projects, this paper puts forward a technical idea of establishing an intelligent decision support system(IDSS). The IDSS is a combination of the traditional decision support system(DSS) and artificial intelligence. On the basis of analyzing the functional requirements of DSS for water hazard prevention and control, an integrated design process of "data-model-solution" is proposed, and …


Deep Mining Under Safe Water Pressure Of Aquifer: Inheritance And Innovation, Yin Shangxian, Lian Huiqing, Xu Bin, Tian Wuzi, Cao Min, Yao Hui, Meng Haopeng Feb 2021

Deep Mining Under Safe Water Pressure Of Aquifer: Inheritance And Innovation, Yin Shangxian, Lian Huiqing, Xu Bin, Tian Wuzi, Cao Min, Yao Hui, Meng Haopeng

Coal Geology & Exploration

The paper reviews the development course of inheritance and innovation of mining under pressure, expounds the concept and the necessary and sufficient conditions of mining under pressure, and on the basis of the connotation of mining under pressure, the base level of erosion is defined as the boundary(interface) of shallow and deep mining under pressure. The paper clarified that mining above confined water is mining under pressure, while mining under aquifer does not belong to the category, and corrects the improper expression of roof and floor pressure in "Coal Mine Safety Regulations". This paper summarizes the theory and technology directly …


Design And Implementation Of Mine Water Hazard Monitoring And Early Warning Platform, Lian Huiqing, Xu Bin, Tian Zhentao, Liu Demin, Yang Yi, Pan Guangyi, Wang Rui Feb 2021

Design And Implementation Of Mine Water Hazard Monitoring And Early Warning Platform, Lian Huiqing, Xu Bin, Tian Zhentao, Liu Demin, Yang Yi, Pan Guangyi, Wang Rui

Coal Geology & Exploration

Any mine water hazard will show different omens. In order to consolidate the foundation of intelligent early warning of water disaster, the connotation of system construction of perception, identification, evaluation, prediction and the interlogical relation are clarified. The mechanism of water inrush is varred for different types of water hazards, we designed three types of multi-mode water inrush typical scenarios and established the corresponding water inrush criteria. In addition, so we proposed two kinds of forecasting methods, namely the precise prediction of deterministic theory and the non-deterministic trend projections including big data and deep learning, which laid a solid theoretical …


Investigation And Simutation On The Model And Prevention Technology Of Water Inrush From Roof Bed Separation, Zhang Wenquan, Wang Zaiyong, Wu Xintao, Shao Jianli, Lei Yu, Wu Xunan Feb 2021

Investigation And Simutation On The Model And Prevention Technology Of Water Inrush From Roof Bed Separation, Zhang Wenquan, Wang Zaiyong, Wu Xintao, Shao Jianli, Lei Yu, Wu Xunan

Coal Geology & Exploration

In order to prevent water inrush from roof separation, a partial backfill scheme is proposed for simulation study. First of all, based on the existing data, many kinds of separation water inrush accidents occurred in China were summarized and analyzed, and the disaster model of separation water accumulation was studied deeply. Then, taking the separation water accident of 1307 working face in the first mining area of a mine in Shaanxi Province as an example, the hydrogeological conditions and the relationship between upper aquifer and separation water inrush were analyzed, and the development characteristics of roof separation space of working …


Experiment Investigation On The Influence Of Mixing Effect On Dispersion Scale Dependence, Ma Ziqi, Dai Zhenxue, Dong Shuning, Wang Hao, Liu Xiaoqian Feb 2021

Experiment Investigation On The Influence Of Mixing Effect On Dispersion Scale Dependence, Ma Ziqi, Dai Zhenxue, Dong Shuning, Wang Hao, Liu Xiaoqian

Coal Geology & Exploration

Dispersivity, a property parameter defined to characterize the degree of dispersion and mixing, is crucial for the prediction and remediation of groundwater contamination. However, in field tracer tests, the real mixing effect has often been ignored. In this paper, an aquifer with horizontal layered structure was simulated by laboratory experiments. Three kinds of media were chosen to reconstructed experimental aquifer. Two monitoring methods, buried sensor and sensor in the well, were adopted to compare the difference of breakthrough curves, so as to investigate the influence of mixing effect in the well on the dispersion scale dependence. The results showed that …


Mechanism Of Water Rock Interaction In Coal Measure Sandstone Aquifer Disturbed By Grouting Engineering: A Case Study Of Taoyuan Coal Mine, Guo Yan, Gui Herong, Wei Jiuchuan, Ni Jianming, Cheng Rongfa, Pang Yingchun, Zhang Zhi, Hong Huang, Hu Mancong, Cui Yali, Liang Zhan, Li Jun, Chen Jiayu, Li Chen Feb 2021

Mechanism Of Water Rock Interaction In Coal Measure Sandstone Aquifer Disturbed By Grouting Engineering: A Case Study Of Taoyuan Coal Mine, Guo Yan, Gui Herong, Wei Jiuchuan, Ni Jianming, Cheng Rongfa, Pang Yingchun, Zhang Zhi, Hong Huang, Hu Mancong, Cui Yali, Liang Zhan, Li Jun, Chen Jiayu, Li Chen

Coal Geology & Exploration

Coal measure sandstone fissure water is one of the important water filling sources in coal mine. This paper takes the Permian coal measures in Taoyuan Coal Mine of Huaibei Coalfield as the research object. Based on the analysis of the water chemical characteristics of coal measures since the grouting treatment of water disaster in the mine, the mechanism of hydrogeochemical action of groundwater and its controlling factors were expounded. The results show that during the grouting treatment project, the main cation in coal measures water was Na+, and the main anion was SO42-; the relationship …


Unsupervised Noise Suppression Method For Depth Network Seismic Data Based On Prior Information Constraint, Chen Wenchao, Liu Dawei, Wei Xinjian, Wang Xiaokai, Chen Dewu, Li Shuping, Li Dong Feb 2021

Unsupervised Noise Suppression Method For Depth Network Seismic Data Based On Prior Information Constraint, Chen Wenchao, Liu Dawei, Wei Xinjian, Wang Xiaokai, Chen Dewu, Li Shuping, Li Dong

Coal Geology & Exploration

Seismic data processing is a critical step in seismic exploration. Due to the complexity of underground structure and surface conditions, seismic data processing needs to go through a series of complex processes, thus forming various types of seismic data. Different types of seismic data have different data characteristics. Exploring and making full use of the data characteristics can not only give full play to the technical potential of processing methods, eliminate the influence of various non-geological factors on the quality of seismic data processing, but also enhance the reliability of seismic data processing. Improving the signal-to-noise ratio and resolution of …


Design And Analysis Of Hole-Forming Technology For Surface Large Diameter Emergency Rescue Borehole, Hao Shijun, Mo Haitao Feb 2021

Design And Analysis Of Hole-Forming Technology For Surface Large Diameter Emergency Rescue Borehole, Hao Shijun, Mo Haitao

Coal Geology & Exploration

Surface large diameter borehole can be used as the escape channel for trapped people underground, and it is one of the important emergency rescue plans when mine accidents cause people trapped underground. However, the conventional large-diameter engineering hole is mainly formed by mud positive circulation and multi-stage reaming, which can not meet the rescue requirements. Focusing on the purpose of rescue and escape of large-diameter hole, this paper expounds the hole forming technology design principles including accurate connecting roadway, optimization of borehole structure, high-efficiency hole forming and safety connecting roadway. According to the specific construction conditions of overburden drilling, second …


Interpretation Method Of High Density 3d Seismic Depth Domain Data In Coal Mining Districts, Meng Fanbin Dec 2020

Interpretation Method Of High Density 3d Seismic Depth Domain Data In Coal Mining Districts, Meng Fanbin

Coal Geology & Exploration

The development height of the water conducting fractured zone is one of the important technical parameters for mine water hazards prediction. In this paper, the combined well-surface microseismic monitoring technology was used to analyze the development characteristics of the water conducting fractured zone in working face 4103 in Wenjiapo coal mine. The results showed that for deep buried coal seams, the microseismic events occured in the advance mining face with advanced influence angle ranging from the minimum of 28° to the maximum of 35°. The stability of overburden decreased due to the faults. Thus, compared with normal bedrock, the overburden …


Research Status And Thoughts For Coal Fines During Cbm Development, Wei Yingchun, Zhang Jin, Cao Daiyong, Meng Tao, Cui Maolin, Wang Anmin Dec 2020

Research Status And Thoughts For Coal Fines During Cbm Development, Wei Yingchun, Zhang Jin, Cao Daiyong, Meng Tao, Cui Maolin, Wang Anmin

Coal Geology & Exploration

Artificial freezing is a commonly used method for stopping water and providing temporary support during the excavation of saturated sand. This study on the damage characteristics of frozen soil lays the foundation for the analysis of the mechanical properties of frozen soil and the stability of frozen bodies. In order to study the damage mechanical properties of frozen sand, three-dimensional laboratory tests on frozen sand with different intermediate principal stress coefficients were carried out at -5℃. Based on the Weibull random distribution of micro element failure of frozen soil, the Drucker-Prager strength criterion was invoked as the statistical distribution variable, …


Application Of Pre-Stack Denoising Technique In Full Digital High Density 3d Seismic Technique In Coal Mining Districts, Yu Jie Dec 2020

Application Of Pre-Stack Denoising Technique In Full Digital High Density 3d Seismic Technique In Coal Mining Districts, Yu Jie

Coal Geology & Exploration

Coalbed methane resource conditions and reservoir physical conditions are the basis of CBM exploration and exploitation. The geological modeling of CBM reservoir was carried out to clarify the spatial distribution of coal reservoir, and explain the difference of single well productivity, which can provide theoretical basis for selection and well drilling. This paper took Baode unit I as research object. Based on the measured data of gas content and well test permeability, the inversion model of gas content and permeability in the study area was established by using support vector machine algorithm(SVM) and transformed F-S permeability calculation formula, and the …


Seismic Attribute Recognition Technology Of Magmatic Rock Intrusive Coal Seam, Wu Bin, Meng Fanbin Dec 2020

Seismic Attribute Recognition Technology Of Magmatic Rock Intrusive Coal Seam, Wu Bin, Meng Fanbin

Coal Geology & Exploration

In order to increase the degree of production of CBM development blocks, when the production of a single well enters a decline period, the development plan needs to be adjusted, and the production increase and stability can be achieved through the measures such as layer adjustment or layer compensation. In terms of time, it is believed that the main coal seam should be developed first when it is put into production. After the decline period, the secondary main coal seam should be supplemented and combined; in space, combined with the development dynamics, the analytic hierarchy process is used to determine …


Technology And Application Of High Efficiency Gas Extraction By Directional Long Borehole Hydraulic Fracturing In Coal Seams Of Medium Hardness And Low Permeability, Guo Chaoqi, Zhao Jizhan, Li Xiaojian, Zhang Jingfei, Wu Shengli, Chen Dongdong, Huang Xingli, Li Baojun Dec 2020

Technology And Application Of High Efficiency Gas Extraction By Directional Long Borehole Hydraulic Fracturing In Coal Seams Of Medium Hardness And Low Permeability, Guo Chaoqi, Zhao Jizhan, Li Xiaojian, Zhang Jingfei, Wu Shengli, Chen Dongdong, Huang Xingli, Li Baojun

Coal Geology & Exploration

Grouting quality test is the key technology for efficient development and utilization of waste land in the goaf of a coal mine, it is of great significance to evaluate the stability of the site and the safety of construction after goaf management. Based on many engineering practices, this paper summarizes the evaluation method of the qualified standards of the grouting quality and the errors existed in the testing work. The results proved that the quality inspection after grouting is a systematic work. The test method could be optimized according to the characteristics of the construction and grouting design requirements, following …


Numerical Simulation Of Fractured Water-Conducting Zone By Considering Native Fractures In Overlying Rocks, Li Ruirui, Chen Luwang, Ou Qinghua, Chen Yifei, Wang Yingxin, Ge Rutao, Peng Zhihong Dec 2020

Numerical Simulation Of Fractured Water-Conducting Zone By Considering Native Fractures In Overlying Rocks, Li Ruirui, Chen Luwang, Ou Qinghua, Chen Yifei, Wang Yingxin, Ge Rutao, Peng Zhihong

Coal Geology & Exploration

The intelligent accurate coal mining needs to construct the high-precision and transparent 3D geological model, and the seismic data interpretation integrated into the dynamic roadway data provide data support for the model. The geological model of roadway is established and forward modeling is carried out to analyze the difference of seismic characteristics caused by a roadway. Based on curvature attribute principle, various seismic curvature attributes were applied to seismic data interpretation, guide the roadway recognition in the seismic data. The coal seam 2 of CJT coalfield was selected as the research object, and the high-quality seismic data and various attribute …


Improvement And Optimization Of Permeability And Strength Properties Of Loess, Zhu Min, Ni Wankui, Yuan Kangze, Li Lan, Li Xiangning, Wang Haiman Dec 2020

Improvement And Optimization Of Permeability And Strength Properties Of Loess, Zhu Min, Ni Wankui, Yuan Kangze, Li Lan, Li Xiangning, Wang Haiman

Coal Geology & Exploration

In order to study the development of secondary faults and fracture, a boundary element method (BEM) combined with seismic interpretation of main faults and geo-mechanics is discussed. Firstly, with the Anderson's theory of faulting, the classification of secondary fault tectonic evolution events is improved under the combination of fault and stress; secondly, the stress tensor order reduction and linear superposition principle are applied to simplify the stress and displacement balance equation, and the Monte Carlo method is used to inverse the paleo-stress field. After all, the equilibrium equation of stress, strain and discontinuous displacement is solved to obtain the current …


Pso-Elm Prediction Model For Surface Deformation Of Mine Slope, Ning Yongxiang, Cui Ximin Dec 2020

Pso-Elm Prediction Model For Surface Deformation Of Mine Slope, Ning Yongxiang, Cui Ximin

Coal Geology & Exploration

During the excavation of the roadway, using reflected in-seam waves detection technique to explore the structure of roadway and accurately interpret the wave impedance interface is of signality for mine production. The method of detecting the position of faults by reflected in-seam waves is usually inaccurate, which is mainly caused by the selected deviation of reflected in-seam waves velocity. In order to reduce the selected deviation of reflected in-seam waves velocity, this paper analyzed the features of reflected in-seam waves velocity of fifteen coal seam in thirteen coal mines and the velocity relationships of reflected in-seam waves, direct in-seam waves …


Application Of Seismic Waveform Classification Technology In Interpretation Of Geological Abnormal Body, Cheng Yan, Zhao Pu, Lin Jiandong, Zhang Xingping Dec 2020

Application Of Seismic Waveform Classification Technology In Interpretation Of Geological Abnormal Body, Cheng Yan, Zhao Pu, Lin Jiandong, Zhang Xingping

Coal Geology & Exploration

Nalinhe No.2 coal mine is the first pair of large-scale mines in the Nalinhe mining area. The water inrush events occur from time to time due to its own complex hydrogeological conditions and strong disturbance of excavation in the initial stage of production, which has caused serious threat to the mining activity safety. Finding the source of gushing water quickly and effectively is the key to control the mine water disaster. Based on the water quality analysis of main aquifers and goaf water samples in Nalinhe No.2 coal mine, and drawing the piper trilinear nomograph water samples, the hydrogeochemical characteristics …


Table Of Contents, The Editors Dec 2020

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Reception Test And Analysis Of Different Geophones In Coal Mining Districts Seismic Exploration, Zhang Libing, Dong Shouhua Dec 2020

Reception Test And Analysis Of Different Geophones In Coal Mining Districts Seismic Exploration, Zhang Libing, Dong Shouhua

Coal Geology & Exploration

During the development process of coalbed methane, the aggregation and sedimentation of coal fines can block the migration channel of coalbed methane and lead to accidents such as stuck pump and buried pump. In order to find out the aggregation and sedimentation characteristics of coal fines with different particle sizes, the aggregation and sedimentation experiments of coal fines with the particle size>140 mesh(<106 μm), 70 to 140 mesh(106-212 μm) and 50 to 70 mesh(212-300 μm) in deionized water were carried out. The aggregation and sedimentation characteristics of coal fines with different particle sizes in deionized water suspension were investigated from the suspension observation, the concentration characteristics of coal fines and the particle size distribution of coal fines in suspension. The results show that with the increase of the time, the color of coal fines suspension becomes lighter to different degrees, and the stratification of coal fines suspension gradually appears, and the suspension of coal fines with the particle size more than 140 mesh was the first to stratify among three suspensions. The smaller the particle sizes of coal fines, the more coal fines float on the top of the suspension, and the larger the particle sizes of coal fines, the more coal fines sink to the bottom of the suspension. The concentration of coal fines in the suspensions decreased to different degrees with the increase of the time. The concentration of coal fines decreased the fastest within 3 minutes after stopping the stirring. The concentration of coal fines with the particle sizes of 70 to 140 mesh in suspension was the largest among three suspensions. According to the particle size distribution curves, the process of aggregation and sedimentation of coal fines was divided into three stages: single peak to double peak(rapid floating and settlement of coal fines), double peak to single peak(rapid accumulation and settlement of coal fines) and single peak(slow sedimentation of coal fines). Coal fines with particle size more than 140 mesh in the suspension was the first to reach the stage of slow sedimentation, and coal fines with particle size of 70-140 mesh in the suspension reached the stage of slow sedimentation at the latest among three suspensions. The mechanism of aggregation and sedimentation of coal fines was discussed from the aspects of the force of coal fines, the extended DLVO theory, and the organic molecular structure of coal fines. The coal samples contain a large number of hydrophobic groups, such as aliphatic hydrocarbon and aromatic hydrocarbon, therefore, they have strong hydrophobicity and low wettability. With the decrease of particle sizes of coal fines, its specific surface area increases significantly, and a large amount of air is absorbed on the surface of coal fines, forming an air film. At the same time, particles of coal fines are adsorbed and aggregated with each other, and many micro pores are formed inside, resulting in that coal fines with small particle size is easy to aggregate and float on the suspension surface.


Application Of Broadband And Wide Azimuth Processing Technology In Full Digital High Density Seismic Exploration In Huaibei Mining Area, Yang Guangming, Jin Xueliang, Zhang Xianxu, Zhi Min, Shan Rui Dec 2020

Application Of Broadband And Wide Azimuth Processing Technology In Full Digital High Density Seismic Exploration In Huaibei Mining Area, Yang Guangming, Jin Xueliang, Zhang Xianxu, Zhi Min, Shan Rui

Coal Geology & Exploration

During coalbed methane well drilling, the drilling fluid contaminates and blocks the pores and fractures of coal seam. In order to find out the difference of pollution degree of drilling fluid coal and the contribution rate of the pores and fractures of different scale to permeability, the coal of Changping mine was taken as the research object, the scanning electron microscopy(SEM) and the Image Pro Plus(IPP) processing technology were used, the parameters such as the average length, the average width, the total area and the total perimeter of the fractures of different scales in coal before and after contamination were …


Characteristics And Monitoring Method Of The Trajectory Of The Radial Cbm Well, Xin Kai, Ji Changjiang, Xiao Chun Dec 2020

Characteristics And Monitoring Method Of The Trajectory Of The Radial Cbm Well, Xin Kai, Ji Changjiang, Xiao Chun

Coal Geology & Exploration

The in-situ stress of 3-1 coal seam in Hongqingliang coal mine was measured by hollow core inclusion measurement, and distribution characteristics of in-situ stress field were obtained in order to solve the problem of serious deformation in mining roadway. Fault structures of grade Ⅰ-Ⅴ in Hongqingliang coal mine were divided by geo-dynamic division method, and the stress areas were divided and the stability of roadways was analysis by rock stress state analysis system. The research showed that the in-situ stress field in Hongqingliang coal mine belongs to the horizontal tectonic stress field, which is dominated by horizontal compressive stress. The …


Late Pleistocene Sedimentary Features And The Palaeoclimatic Background In Hongsibao Basin, Li Zhenhong, Cui Jiawei, Li Chaozhu, Jiang Boyu, Huang Ting Dec 2020

Late Pleistocene Sedimentary Features And The Palaeoclimatic Background In Hongsibao Basin, Li Zhenhong, Cui Jiawei, Li Chaozhu, Jiang Boyu, Huang Ting

Coal Geology & Exploration

The chuck is an important part of the coal mine tunnel drilling rig. The performance of the chuck directly affects the efficiency and quality of drilling. Aiming at the problems of the rubber cylinder hydraulic chuck. a new radial piston hydraulic chuck is studied. The objective of this paper is to devise a new radial piston hydraulic chuck instead of rubber-sleeve hydraulic chuck. Then, the motion mathematical model of radial piston hydraulic chuck was established based on the radial piston chuck clamping and loosening of system structure and working principle. At the same time, a dynamic co-simulation of chuck hydraulic …


High Rank Coal Structure And Log Interpretation Method Of Fracture Pressure In Shouyang Block, Li Songlin, Li Zhongcheng, Wang Lina, Duan Jing, Xiang Nian Dec 2020

High Rank Coal Structure And Log Interpretation Method Of Fracture Pressure In Shouyang Block, Li Songlin, Li Zhongcheng, Wang Lina, Duan Jing, Xiang Nian

Coal Geology & Exploration

In order to accurately describe the distribution of surface subsidence basin, and based on the power exponential function model and the subsidence features, the surface subsidence basin model of long-wall working face along strike with gently inclined coal seam was established concerned the combination of theoretical analysis and numerical simulation method. The influencing factors of model parameters and the changing patterns of parameters were analyzed, and the applicability and the predicting accuracy of the model were verified. The results showed that parameter n reflected the range of the bottom size of the sinking basin, which was mainly related to the …


Biogas Production Of Lignite And Variation Characteristics Of Cations In Liquid Phase System, Zhao Han, He Huan, Wang Jiangze, Song Yanli, Niu Jianglu, Chen Linyong, Guo Xin, Liu Jian, Guan Jiadong, Yuan Xuefang Dec 2020

Biogas Production Of Lignite And Variation Characteristics Of Cations In Liquid Phase System, Zhao Han, He Huan, Wang Jiangze, Song Yanli, Niu Jianglu, Chen Linyong, Guo Xin, Liu Jian, Guan Jiadong, Yuan Xuefang

Coal Geology & Exploration

Liupan Shan lies between the Tibetan plateau and Ordos block and has been under the remote effect of the northeastward extension of the Tibetan plateau. The former research about the uplift of Liupan Shan mainly focused on the petrology, structural deformation or tectonic evolution study from the Cretaceous to early period of Cenozoic. However, the Late Pleistocene geological study closely connected with the human activities was rarely mentioned. In this study, we carried out systematic sedimentary research in the Qingshuihe basin adjacent to the Liupan Shan tectonic belt, re-determine the sedimentary sequence at first, then reverse the uplift history of …


Pattern And Effect Of The High Density 3d Seismic Exploration In Coal Mining Districts, Jin Xueliang, Wang Qi Dec 2020

Pattern And Effect Of The High Density 3d Seismic Exploration In Coal Mining Districts, Jin Xueliang, Wang Qi

Coal Geology & Exploration

Graphene is an emerging carbon nanomaterial in the 21st century, has excellent properties and shows great application potential in many fields. Coal is the most abundant and the cheapest carbon source with unique structure and material composition. The application of coal in the development and the application of new carbonaceous materials such as graphene and their composites is a work worthy of further exploration. The development of coal-based graphene can both promote the clean utilization of coal and enhance the added value of coal resources. In this paper, the research developments in coal structure, the mechanism of coal graphitization, as …


Summary Of High Density 3d Seismic Exploration In The Mining Districts Of Coal Mines In Shanxi Province, Hou Zeming, Yang Deyi Dec 2020

Summary Of High Density 3d Seismic Exploration In The Mining Districts Of Coal Mines In Shanxi Province, Hou Zeming, Yang Deyi

Coal Geology & Exploration

Based on the analysis of geological characteristics of the study area, it is considered that the geological conditions of H2S occurrence are the capping effect of dense surrounding rock on the roof and floor, the water-conducting fractured zone is unable to guide the overlying aquifer, and the low degree of coal metamorphism is not conducive to H2S adsorption, resulting in maximum H2S concentration of about 0.001 4% in the main mined coal seam 4 during the construction of Yadian mine at the north of Binchang mining area. Through the analysis of sulfur distribution, sulfate …