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- Keyword
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- Numerical simulation (87)
- Coalbed methane (47)
- Coal mine (39)
- Ordos Basin (31)
- Gas drainage (28)
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- Deep learning (27)
- Permeability (27)
- Pore structure (27)
- Coalbed methane (CBM) (25)
- Deep coalbed methane (24)
- Hydraulic fracturing (23)
- Tar-rich coal (23)
- Directional drilling (21)
- Underground coal mine (20)
- Coal (17)
- Deep coalbed methane (CBM) (17)
- Qinshui Basin (15)
- Horizontal well (14)
- Open-pit coal mine (14)
- Rock burst (14)
- Shale gas (13)
- Underground coal gasification (UCG) (13)
- Fracture (12)
- Machine learning (12)
- Mine water (12)
- Prospect (12)
- Fractal dimension (11)
- Helium (11)
- Intelligent mining (11)
- Microstructure (11)
- Publication Year
Articles 1021 - 1050 of 1799
Full-Text Articles in Engineering
Study On Long-Distance Fixed-Point Sealed Coring Technology In Broken-Soft Coal Seam, Long Weicheng, Sun Siqing, Chen Jian
Study On Long-Distance Fixed-Point Sealed Coring Technology In Broken-Soft Coal Seam, Long Weicheng, Sun Siqing, Chen Jian
Coal Geology & Exploration
With the rapid development of mining, drilling and other technologies in the field of coal mine and the increasing demand for enhancing production and profit in the coal mine, the demand is increasingly urgent for detection of coal seam gas content in the initial stage. In recent years, the gas content measurement technology of underground long borehole high-pressure water sealed coring has been applied in the medium hard coal seam mining area with remarkable effects, but its application is limited in broken-soft coal seam. A number of issues are encountered that easy breakup of coal core sample, easy wall collapse …
Research On Hydraulic Fracturing Technology And Equipment Of Directional Long Drilling With Sand In Coal Seam Roof, Zhang Jian, Liu Le, Zhao Jizhan, Sun Siqing, Wang Chenyang
Research On Hydraulic Fracturing Technology And Equipment Of Directional Long Drilling With Sand In Coal Seam Roof, Zhang Jian, Liu Le, Zhao Jizhan, Sun Siqing, Wang Chenyang
Coal Geology & Exploration
Due to low permeability, fast gas-rate decline, uneven fracturing, easy fracture closure, it is difficult to perform advance gas extraction in broken-soft coal seams. Aimed at these issues, this study has been proposed a new idea to enhance the coalbed permeability and eventually the gas extraction, which is based on roof-supporting, long-reach directional drilling, and hydraulic fracturing. Corresponding equipment including fracturing pump unit, directional sandblasting perforation assembly, sand control packer and tools have been developed. Specifically, the pumping unit is capable of a pumping rate up to 90 m3/h, a pumping pressure up to 70 MPa, and a …
Optimized Design And Surface Additive Technology Of Pdc Bit For Hard Rock Directional Drilling, Wang Chuanliu, Jin Xin, Gao Xiaoliang, Zhang Peng
Optimized Design And Surface Additive Technology Of Pdc Bit For Hard Rock Directional Drilling, Wang Chuanliu, Jin Xin, Gao Xiaoliang, Zhang Peng
Coal Geology & Exploration
Directional long drilling is the main technical means of gas and water hazard control in coal mines, and the performance of PDC directional bit is an important factor which affects the drilling efficiency in hard rock. In view of frequent tripping and low that caused by the broken PDC bit body and PDC tooth collapse in the construction of directional long drilling in the roof and floor of coal seams, the principle of equal cutting teeth distribution is used to optimize the blade teeth distribution to reduce the impact damage of the cutter. Through the simulated analysis of fluid mechanics, …
Research Progress And Development Trend Of Staged Hydraulic Fracturing Technology In Long-Borehole Underground Coal Mine, Sun Siqing, Li Wenbo, Zhang Jian, Chen Dongdong, Zhao Jizhan, Zheng Kaige, Long Weicheng, Wang Chenyang, Jia Bingyi, Du Tianlin, Liu Le, Yang Huan, Dai Nan
Research Progress And Development Trend Of Staged Hydraulic Fracturing Technology In Long-Borehole Underground Coal Mine, Sun Siqing, Li Wenbo, Zhang Jian, Chen Dongdong, Zhao Jizhan, Zheng Kaige, Long Weicheng, Wang Chenyang, Jia Bingyi, Du Tianlin, Liu Le, Yang Huan, Dai Nan
Coal Geology & Exploration
Since the “13th Five-Year Plan”, significant progress has been made in the directional long-borehole staged hydraulic fracturing technology, equipment development and engineering demonstration application of underground coal mine through the technical research, equipment development and engineering test with directional long-borehole and staged hydraulic fracturing technology in combination, focusing on the two major issues of regional permeability enhancement, efficient gas drainage and rock weakening treatment of hard roof for coal seams in underground coal mine in China. It is mainly manifested in the following four aspects: (1) Two staged hydraulic fracturing technologies and tools with/without rig movement have been developed. Specifically, …
Study Of Technologies And Equipment Of Continuous Hydraulic Sand Fracturing For Permeability Enhancement At High Pressure Side Of Coal Mine Downhole, Jia Bingyi, Li Shugang, Chen Dongdong, Lin Haifei, Zheng Kaige, Sun Siqing, Zhao Jizhan
Study Of Technologies And Equipment Of Continuous Hydraulic Sand Fracturing For Permeability Enhancement At High Pressure Side Of Coal Mine Downhole, Jia Bingyi, Li Shugang, Chen Dongdong, Lin Haifei, Zheng Kaige, Sun Siqing, Zhao Jizhan
Coal Geology & Exploration
The technological concept of sand fracturing at the high pressure side is proposed against the present situation where the coal mine downhole operation space is small, the power and water supply capacities are limited, and the surface sand fracturing equipment cannot be applied directly in the coal mine downhole. On the basis of the principle of sand mixing and carrying through hydrodynamic impact, the continuous hydraulic sand fracturing equipment at the high pressure side was developed. Such equipment requires no external power source for sand mixing. It forms cyclone impact through the changes in the flow regime and flow field …
Dynamic Disaster Evolution Mechanism Of High Mine Pressure At Hard Roof And Advance Area Prevention And Control Technology, Zheng Kaige, Wang Lintao, Li Bingang, Li Yanjun, Yang Huan, Yang Sen, Dai Nan, Wang Haojie, Wang Zeyang, Xi Jie
Dynamic Disaster Evolution Mechanism Of High Mine Pressure At Hard Roof And Advance Area Prevention And Control Technology, Zheng Kaige, Wang Lintao, Li Bingang, Li Yanjun, Yang Huan, Yang Sen, Dai Nan, Wang Haojie, Wang Zeyang, Xi Jie
Coal Geology & Exploration
The overlying roof on the hard roof working bench is usually not likely to fall off, while tends to form dynamic pressure disaster. The stress evolution characteristics and roof breaking mechanism before and after hard roof weakening were analyzed and revealed using the methods of numerical simulation and theoretical analysis, and the advance area prevention and control technology were proposed and applied in the field practice, for the typical dynamic disaster problem of high mine pressure that was caused by the hard roof against the background of the Buertai Coal Mine in the Shendong Mine Area. As indicated by the …
Enhanced Gas Drainage Technology By Staged Fracturing In Long Bedding Borehole In Hard Coal Bed Of Underground Coal Mine And Its Application, Wang Chenyang, Li Shugang, Zhang Yongtao, Guo Yi, Sun Siqing, Chen Dongdong, Dou Chengyi
Enhanced Gas Drainage Technology By Staged Fracturing In Long Bedding Borehole In Hard Coal Bed Of Underground Coal Mine And Its Application, Wang Chenyang, Li Shugang, Zhang Yongtao, Guo Yi, Sun Siqing, Chen Dongdong, Dou Chengyi
Coal Geology & Exploration
In view of the problems of rapid attenuation, long period and low efficiency of gas drainage in hard coal bed, the enhanced gas drainage technology of increasing the permeability of coal bed by staged fracturing in long bedding borehole was put forward for the medium-to-hard coal bed. Herein, research was conducted on No.4 coal bed of Shaanxi Binchang Mining Area. Specifically, the change characteristics of micro-pore structure of coal body before and after hydraulic fracturing were comparatively analyzed by high-resolution electron microscope (SEM) in the laboratory. Meanwhile, the stress characteristics of packer and the stability of borehole were simulated with …
Floor Failure Law Of Extra-Thick Coal Seam In Fully Mechanized Caving Mining, Guo Guoqiang
Floor Failure Law Of Extra-Thick Coal Seam In Fully Mechanized Caving Mining, Guo Guoqiang
Coal Geology & Exploration
The coal mining on the high-artesian water body will cause floor disturbance and damage, and lead to the thinner effective waterproof stratum, which enhances the risk coefficient of water bursting at the floor. Grouting modification of the target horizon is an effective governing measure. However, the grouting within the floor damage scope will waste a large amount of grout and affect the project effect. Therefore, it is especially important to carry out the study of the damage depth and regularity of the coal seam floor. Accordingly, the 5105 working bench of the Yushupo Coal Mine in Shanxi was adopted as …
Study Of Constitutive Model Of Frozen Sandstone Damage Based On Weibull Distribution, Yi Ming, Zhao Tao, Ma Feifei, Wang Lei, Yuan Chao
Study Of Constitutive Model Of Frozen Sandstone Damage Based On Weibull Distribution, Yi Ming, Zhao Tao, Ma Feifei, Wang Lei, Yuan Chao
Coal Geology & Exploration
Abstract: The deformation and destruction characteristics of frozen rock is a basic mechanical problem encountered during the construction using the freezing method. Under the action of load, the mechanical characteristics and deformation characteristics are greatly different for the rock with different freezing temperatures, which significantly affects the safety and stability of the freezing wall. Therefore, the study of the damage constitutive relation of the frozen rock is significant for instructing the freezing method design and construction. In order to analyze the whole process of the frozen rock deformation and destruction under load action, the Weibull distribution was adopted to describe …
Analysis On Spatio-Temporal Evolution Law Of Freezing Temperature Field In Eastern Shaft Of Qinan Coal Mine, Huang Shiqing, Rong Chuanxin, Long Wei, Ma Haochen, He Junzhen
Analysis On Spatio-Temporal Evolution Law Of Freezing Temperature Field In Eastern Shaft Of Qinan Coal Mine, Huang Shiqing, Rong Chuanxin, Long Wei, Ma Haochen, He Junzhen
Coal Geology & Exploration
Three numerical calculation models of the freezing temperature fields with different soil nature and different burial depths, i.e. the calcareous clay horizon with the burial depth of 218 m, the fine sand horizon with the burial depth of 225 m and the sandy clay horizon with the burial depth of 259 m, were established respectively using the finite element software COMSOL Multiphysics based on the actual forming locations of freezing holes, with the engineering background of using the freezing method in shaft sinking for the eastern air shaft of Qinan Coal Mine Anhui Province and the study object of the …
Experimental Study On Power Matching Of Modular Double Pumping Stations Of Tunnel Drilling Rig, Lu Feifei, Fan Dong, Tian Hongliang
Experimental Study On Power Matching Of Modular Double Pumping Stations Of Tunnel Drilling Rig, Lu Feifei, Fan Dong, Tian Hongliang
Coal Geology & Exploration
In order to solve the problems of heavy weight, relocation and transportation of the power pumping station of tunnel drilling rigs, it is proposed to divide the pumping station through modular design, and adopt the solution of small-displacement, dual-power and dual-pump confluence, effectively reducing the transportation size and weight of a single pump station. A single-pump station or a double-pump confluence is chosen according to the working conditions to improve the flexibility of the drilling rig and reduce energy consumption. The load-sensing system has the advantages of energy saving, good load adaptability, and convenient speed regulation. However, when the dual-load-sensing …
Table Of Contents, The Editors
Experimental Study On The Mechanical Properties Of Coal-Like Materials For Hydraulic Fracturing Simulation, Zhai Cheng, Zheng Yangfeng, Yu Xu, Xu Jizhao, Sun Yong, Cong Yuzhou, Tang Wei, Li Yujie, Zhu Xinyu, Chen Aikun
Experimental Study On The Mechanical Properties Of Coal-Like Materials For Hydraulic Fracturing Simulation, Zhai Cheng, Zheng Yangfeng, Yu Xu, Xu Jizhao, Sun Yong, Cong Yuzhou, Tang Wei, Li Yujie, Zhu Xinyu, Chen Aikun
Coal Geology & Exploration
Simulation experiments on hydraulic fracturing of the coal seam in the laboratory are an effective method to study the mechanism of fracturing and enhancing permeability of coal-rock mass by hydraulic fracturing in coal mines. However, the technology in-situ sampling for large-size coal mass is immature, and the existing large-size coal samples are mostly taken from the stress-relaxation area, which can be further damaged in the transportation and preparation processes, causing large dispersion in test results. Therefore, The use of coal-like materials is a viable option to replace large-size raw coal for hydraulic fracturing simulation experiments. The mechanical properties of coal-like …
High-Efficiency Regional Gas Drainage Model After Hydraulic Fracturing Of Comb-Shaped Long Boreholes In The Roof Of Broken Soft And Low Permeability Coal Seam, Chen Dongdong, Wang Jianli, Jia Bingyi, Xi Jie
High-Efficiency Regional Gas Drainage Model After Hydraulic Fracturing Of Comb-Shaped Long Boreholes In The Roof Of Broken Soft And Low Permeability Coal Seam, Chen Dongdong, Wang Jianli, Jia Bingyi, Xi Jie
Coal Geology & Exploration
Advanced management of gas enrichment area is an important guarantee to realize safe, efficient and intelligent mining in coal mine. Aiming at the problem of high-efficiency gas drainage in broken and soft coal seam region, taking No.3 coal seam in Hancheng mining area as the research object, a gas drainage mode of comb-shaped long borehole hydraulic fracturing in the roof of coal seam is proposed. The applicability of the model is verified by means of theoretical analysis, numerical simulation and field test, and the fracture propagation law, gas drainage mechanism, and fracturing curve features of comb-shaped borehole in adjacent roof …
Experimental Study Of Hydraulic Fracture Evolution With Materials Similar To The Structural Plane, Li Quangui, Wu Xiaobin, Hu Qianting, Liu Le, Shi Jialin, Song Mingyang
Experimental Study Of Hydraulic Fracture Evolution With Materials Similar To The Structural Plane, Li Quangui, Wu Xiaobin, Hu Qianting, Liu Le, Shi Jialin, Song Mingyang
Coal Geology & Exploration
The structural plane extensively occurs in coal measures, and is one of the key factors affecting the hydraulic fracturing effect of coal/rock. The fabrication time and filling material types of the structural plane were adjusted to obtain the coal/rock specimens without the filling structural plane, or the coal/rock specimens with the filling structural plane. The physical experiment for hydraulic fracturing was carried out to find out the effect and action mechanism of the structural plane type and injected flow rate on hydraulic fracture extension. As indicated by the result, in the condition of the injected flow rate of 50 mL/min, …
Analysis And Prospect Of Precise Prevention And Control Technical System Ahead Of Large Areas And Time For Gas Disasters In China, Liu Cheng, Sun Dongling, Wu Wenbin, Li Liangwei, Sun Zhongguang
Analysis And Prospect Of Precise Prevention And Control Technical System Ahead Of Large Areas And Time For Gas Disasters In China, Liu Cheng, Sun Dongling, Wu Wenbin, Li Liangwei, Sun Zhongguang
Coal Geology & Exploration
To meet the rapid development of coal mine automation and intelligent production and the urgent need for rapid prevention and regional management outburst, and to promote the development of the gas disaster control technology system in large areas of coal mines, this paper aims to solve the problem of traditional coal seam drilling gas drainage technology, which is “not deep enough to be drilled and cannot be pumped out and cannot be tested.” It analyzes the application effects of technical equipment such as directional drilling, surface wells, staged hydraulic fracturing, deep hole sampling, and detection while drilling in various geological …
Hydrochemical Characteristics And Source Analysis Of Deep Groundwater In Qianyingzi Coal Mine, Chen Kai, Liu Qimeng, Liu Yu, Peng Weihua, Wang Zitao, Zhao Xiang
Hydrochemical Characteristics And Source Analysis Of Deep Groundwater In Qianyingzi Coal Mine, Chen Kai, Liu Qimeng, Liu Yu, Peng Weihua, Wang Zitao, Zhao Xiang
Coal Geology & Exploration
The shallow coal resources in China have been gradually depleted. Under the condition that the deep coal exploitation has been started, the threat from the high-artesian limestone water at the coal seam floor is greater. Deep understanding of the hydrochemical composition control mechanism in the aquifer of the mine area is an important scientific precondition for pertinently carrying out water hazard prevention and control. In order to find out the qualitative and quantitative sources of the conventional ions which in the deep ground water of the Anhui Qianyingzi Coal Mine, the 22 conventional ion concentrations in limestone water were analyzed …
Abnormal Response Characteristic Simulation During Transient Electromagnetic Detection In Mine Borehole, Zhang Jun
Coal Geology & Exploration
Conventional mine transient electromagnetic advance detection method is greatly influenced by the condition outside of the mine, which leads to the inaccurate location in anomalous body detection. In order to solve this problem, an advance detection method for measuring the three-component signals of the transient electromagnetic field in the down-hole borehole was proposed to carry out numerical simulation for the abnormal response characteristics from the different locations of the plane where the receiving coil is located and the different orientations of the anomalous body. The principle of borehole transient electromagnetic detection was analyzed, and the test design and construction design …
Study Of Advance Elaborate Detection With Transient Electromagnetic Method For Mine With Closed Poor Boreholes, Huang Zhongzheng, Jiang Guoqing, Wang Jun, Cheng Jiulong, Ma Zhi, Tian Chuxiao, Xin Chengtao
Study Of Advance Elaborate Detection With Transient Electromagnetic Method For Mine With Closed Poor Boreholes, Huang Zhongzheng, Jiang Guoqing, Wang Jun, Cheng Jiulong, Ma Zhi, Tian Chuxiao, Xin Chengtao
Coal Geology & Exploration
Closed poor boreholes connect aquifers at some degree to form well concealed water diversion channels, which poses a water hazard threat on either tunneling or working bench recovery. In order to discuss the effectiveness of using the transient electromagnetic method in the advance detection of closed poor boreholes for the mine, the 3D geologic-geophysical model of the closed poor boreholes in front of the tunneling working bench was established based on the full-space transient electromagnetic theory to simulate and study the response characteristics of the full-space transient electromagnetic field in the influence area model of closed poor boreholes. As indicated …
Experimental Study On Nondestructive Testing Of Anchor Cable In Pumped Storage Power Station, Yan Liangping, Zhou Liming, Cui Botao, Wang Bolin, Lu Jiangang
Experimental Study On Nondestructive Testing Of Anchor Cable In Pumped Storage Power Station, Yan Liangping, Zhou Liming, Cui Botao, Wang Bolin, Lu Jiangang
Coal Geology & Exploration
In order to demonstrate the effect of elastic wave reflection method, the nondestructive testing test of anchor cables was carried out at the bank slope of Fukang Pumped Storage Power Station in Xinjiang. On the basis of the basic theory of elastic wave reflection method, the anchor cable sensor is embedded, and the data acquisition, signal excitation position and wave velocity of anchor body in the process of nondestructive testing of anchor cable are systematically studied. The following results are obtained: When the receiving sensor position is fixed and the excitation part is the steel strand where the receiving sensor …
Development And Application Of A Retractable Slip Overshot In Underground Coal Mines, Wu Tao
Development And Application Of A Retractable Slip Overshot In Underground Coal Mines, Wu Tao
Coal Geology & Exploration
The stuck and buried drills in underground coal mines often lead to accidents of broken drill pipes in the holes. At present, the success rate of the commonly used fishing methods of male and female fishing tap buckle is low, which not only consumes a lot of manpower and material resources, but also affects the production progress of coal mining. Based on this, a retractable slip overshot with the structural design of the cooperation between the slips and the outer cylinder through the wedge-shaped spiral surface has been proposed, which converts the pull-out force of the drill rod into a …
Table Of Contents, The Editors
Fast Quantitative Interpretation Of Surface-Borehole Tem Using Transient Impulse Peak Time, Zhi Qingquan, Wu Junjie, Wang Xingchun, Yang Yi, Zhang Jie, Deng Xiaohong
Fast Quantitative Interpretation Of Surface-Borehole Tem Using Transient Impulse Peak Time, Zhi Qingquan, Wu Junjie, Wang Xingchun, Yang Yi, Zhang Jie, Deng Xiaohong
Coal Geology & Exploration
Due to the complex response law of the surface-borehole Transient Electromagnetic Method (TEM), qualitative analysis and semi-quantitative interpretation are the most widely used interpretation methods. However, the methods cannot obtain the resistivity parameter of the earth directly. To solve this problem, a fast quantitative interpretation method based on transient impulse peak time is proposed. Firstly, the expression of uniform half-space surface-borehole transient electromagnetic response is given, and the impulse time characteristics of surface-borehole transient electromagnetic response are analyzed. The results show that the deeper the receiving point is buried and the higher the earth conductivity is, the later the transient …
Key Technical Progress Of Water Cutoff Curtain Technology In Open-Pit Coal Mines In China, Huang Xuanming, Zhang Yan, Wang Mingxing, Teng Qingshan, Li Guozhi
Key Technical Progress Of Water Cutoff Curtain Technology In Open-Pit Coal Mines In China, Huang Xuanming, Zhang Yan, Wang Mingxing, Teng Qingshan, Li Guozhi
Coal Geology & Exploration
The method of pumping and discharging groundwater is widely used in open-pit coal mines for groundwater control in China to meet the requirements of safe coal mining, which causes great damage to water resources and seriously affects the ecological environment around coal mines. In recent years, with the all-round development of the economy, China has put forward higher requirements for ecological environment protection and ecological civilization construction. How to optimize and change the groundwater control mode and reduce the volume of pit drainage is a new subject generally in water prevention and control of open-pit coal mines. The use of …
Application And Effect Evaluation Of Water Cutoff Curtain Technology In Yuanbaoshan Open-Pit Coal Mine, Gao Sheng, Li Guozhi, Guo Yingjie, Tian Zenglin, Shao Dongmei, Zhu Hongjun
Application And Effect Evaluation Of Water Cutoff Curtain Technology In Yuanbaoshan Open-Pit Coal Mine, Gao Sheng, Li Guozhi, Guo Yingjie, Tian Zenglin, Shao Dongmei, Zhu Hongjun
Coal Geology & Exploration
Yuanbaoshan open-pit coal mine of Inner Mongolia is a rare extra large water rich open-pit coal mine at home and abroad. In order to resolve the problems of high production cost and high environmental risk caused by drainage for many years, it is plan to adopt water cutoff curtain technology to closure the seepage supply channel. By analyzing the hydrogeological and engineering geological conditions of the mine, the groundwater water control method of combining arc semi-closed curtain with group wells drainage hydraulic curtain was proposed. The curtain test study was carried out in the mine 452 m flat plate by …
Water Level Evolution Pattern Of Loose Layers Under Water Cutoff Curtain In Ecologically Fragile Open-Pit Mines, Wang Hai, Wang Yonggang, Zhang Yan, Sun Hao, Miao Hechao
Water Level Evolution Pattern Of Loose Layers Under Water Cutoff Curtain In Ecologically Fragile Open-Pit Mines, Wang Hai, Wang Yonggang, Zhang Yan, Sun Hao, Miao Hechao
Coal Geology & Exploration
Eastern Inner Mongolia of China is characterized by a fragile ecological environment and scarce water resources. High-intensity mining in open-pit coal mines has caused drastic changes in the recharge, runoff and discharge of the groundwater system, resulting in a significant drop in the water level of the loose layer, depletion of surface stream flow and destruction of the ecological environment. To reveal the evolution of water level in the loose layer under the water cutoff curtain in ecologically fragile open-pit mines, analyze the characteristics of groundwater distribution in and the influence of mining on the water level of loose layers, …
Ecological Restoration Strategies For Coal Mines In China Based On Vegetation Zones And Ecological Sensitivity, Zhou Hongxuan, Wang Zhaoqing, Pu Hongtong, Tao Guixin, Sun Jing
Ecological Restoration Strategies For Coal Mines In China Based On Vegetation Zones And Ecological Sensitivity, Zhou Hongxuan, Wang Zhaoqing, Pu Hongtong, Tao Guixin, Sun Jing
Coal Geology & Exploration
Coal is the main source of energy in China and the most important driver of our development for a long time. It is predicted that coal is going to be the main energy source for our social and economic development in the future. However, the long-term coal mining activities in China have caused serious damage to the ecological environment and comprehensive ecological restoration is urgently needed. At present, most coal mine ecological restoration is limited within a small scale in China, such as one or several mine areas, lacking of ecological restoration planning at the national spatial level, and corresponding …
Techniques Of Double-Pipe And Double-Acting Directional Drilling With Air In Broken And Soft Coal Seams In Underground Coal Mines, Wang Li
Coal Geology & Exploration
In the broken and soft coal seam drilling, the outburst and collapse of the hole occur easily, resulting in shallow drilling depth and low rate of hole forming, which seriously restrict the efficient gas control in the broken and soft coal seam. With the rise of gas control models, such as replacing roadway with holes and progressive drainage of the broken and soft coal seam, higher requests have been put forward to the gas drainage hole. The further improvement of the drilling depth, drilling accuracy and hole forming rate of the broken and soft coal seam can meet the needs …
Water Control Principle Of Lateral Water Cutoff Curtain And Numerical Analysis Of Its Water Interception Effect In Yuanbaoshan Open-Pit Coal Mine——Taking Yuanbaoshan Open-Pit Coal Mine As An Example, Zhao Chunhu, Wang Mingxing, Cao Haidong, Qu Guowen, Wang Yong, Guo Yingjie
Water Control Principle Of Lateral Water Cutoff Curtain And Numerical Analysis Of Its Water Interception Effect In Yuanbaoshan Open-Pit Coal Mine——Taking Yuanbaoshan Open-Pit Coal Mine As An Example, Zhao Chunhu, Wang Mingxing, Cao Haidong, Qu Guowen, Wang Yong, Guo Yingjie
Coal Geology & Exploration
In the process of open-pit coal mining, drainage is an important aspect causing the loss of groundwater resources. Taking Yuanbaoshan open-pit coal mine in Chifeng City, Inner Mongolia as the research object, this paper analyzes the control principle of the curtain wall construction driven by open-pit mining on the groundwater system according to the hydrogeology of the study area and the characteristics of open-pit coal mine development. It comes to the conclusion that the weaker the permeability of the curtain wall, the greater the thickness, and shortening the distance from the recharge water body is the basic idea of reducing …
Research On Three-Component Responses Characteristics Of Axial Anisotropy Tunnel-Hole Transient Electromagnetic, Guo Jianlei, Gao Xiaowei, Hou Yanwei
Research On Three-Component Responses Characteristics Of Axial Anisotropy Tunnel-Hole Transient Electromagnetic, Guo Jianlei, Gao Xiaowei, Hou Yanwei
Coal Geology & Exploration
Large interpretation errors may exist in exploration areas with obvious conductivity anisotropy when applying tunnel-hole transient electromagnetic method. In this paper, the control equation is built by introducing the conductivity anisotropy tensor, which allows the current density of the rectangular loop source to be added into the Maxwell equation Ampere loop theorem based on the finite difference time domain (FDTD) algorithm in order to realize the loading of any current source. The control equation is discretized by the difference instead of the differential to realize the forward calculation of the tunnel-hole transient electromagnetic 3D model. Forward modeling is carried out …