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Articles 1891 - 1920 of 2611
Full-Text Articles in Sustainability
Application Of High Precision Gravity Survey In Detecting Mined-Out Areas Of Fushun Coal Mine, Huan Hengfei, Gao Tie, Zhao Haiqing, Zhao Weijun, Guo Canwen, Shi Bin
Application Of High Precision Gravity Survey In Detecting Mined-Out Areas Of Fushun Coal Mine, Huan Hengfei, Gao Tie, Zhao Haiqing, Zhao Weijun, Guo Canwen, Shi Bin
Coal Geology & Exploration
In order to find out the location, depth and distribution range of the mined-out areas in Fushun coal mine, and comprehensively considering the factors affecting the geophysical methods in the cities, the method of high-precision gravity survey was firstly used to study the mined-out areas in the area. Firstly, by analyzing the physical differences of the mined-out areas, a theoretical model was established for forward calculation and preliminarily studied on applicability of the gravity method. Then, a large-scale work of high-precision gravity survey was arranged in the study area, and through potential field separation,3D apparent density inversion and boundary identification …
Drainage Technology And Test Of Stratified Pressure Control With Four-Channels Of Cbm Well In Double Coal Seams, Pang Tao, Jiang Zaibing, Li Bingang, Du Xinfeng
Drainage Technology And Test Of Stratified Pressure Control With Four-Channels Of Cbm Well In Double Coal Seams, Pang Tao, Jiang Zaibing, Li Bingang, Du Xinfeng
Coal Geology & Exploration
Aiming at the problems of mutual interference between layers and serious damage in reservoirs in the production process of double-coal CBM wells, a four-channel stratified pressure control drainage technology was proposed, in the process of drainage, two coal seams were controlled in different pressure systems to achieve the purpose of stratified production and CBM well drainage device with four-channel packer, monitoring equipment, multi-channel tubing centralizer, roller sucker rod centralizer and auxiliary communication tube for double coal seams was developed. Field application test shows that the four-channel packer can achieve the isolation effect according to the needs, so that the two …
Table Of Contents, The Editors
Research And Application Of Casing Milling And Fishing Technology In Floor Comb-Shaped Directional Borehole, Guan Qiangsheng, Wei Hongchao
Research And Application Of Casing Milling And Fishing Technology In Floor Comb-Shaped Directional Borehole, Guan Qiangsheng, Wei Hongchao
Coal Geology & Exploration
In order to solve the problem that using the conventional strong-force rotary drawing process for borehole sticking accident in comb-shaped directional borehole in floor is not ideal, and using reverse thread drill pipe or strong twist cause big time and economic loss, through the calculation and analysis of the passing capacity of casing milling and fishing pipe in the curved hole, the technical parameters of casing milling and fishing, the sticking accident of floor comb-shaped directional borehole with the depth of 344 m in a coal mine in Henan Province was successfully solved. The application results show that the maximum …
Evaluation Of Coalbed Methane Drainage Effect For Multi-Target Seams In Jincheng Region, Yang Jianchao, Li Guihong, Liu Yuhui, Li Guofu, Wang Chaoshuai, Sun Tianyu
Evaluation Of Coalbed Methane Drainage Effect For Multi-Target Seams In Jincheng Region, Yang Jianchao, Li Guihong, Liu Yuhui, Li Guofu, Wang Chaoshuai, Sun Tianyu
Coal Geology & Exploration
The study of the multi-target seams drainage effect on coalbed methane wells has great value, including coal safe mining, underground gas control, determination of development technical indicators, single well production, rational division of development layer, efficient development of coalbed methane, and development of medium and long-term coalbed methane development planning. Taking Chengzhuang mine of Jincheng as an example, the sampling data of the extraction effect in the middle and late stages of development are compared with the original gas content of the adjacent wells to evaluate the extraction effect, and the main control factors affecting the drainage effect are analyzed …
Supporting Technology Of Roadway Crossing Fractured Zone Of Fault Under Dynamic And Static Load, Song Weihua, Di Chunlei, Deng Zhaorui
Supporting Technology Of Roadway Crossing Fractured Zone Of Fault Under Dynamic And Static Load, Song Weihua, Di Chunlei, Deng Zhaorui
Coal Geology & Exploration
The gateway 5303 encountered multiple normal faults during the driving in Changping mine of Jinmei Group. For the purpose that the gateway can pass through the faults safely and rapidly and ensure applicative methods and scope of supporting. So based on the principle of maximum principal stress and fracture damage mechanics of rock, the paper analyzes the crushing mechanism of the normal fault zone under dynamic and static load from macroscopic and microscopic perspectives. Then, the plastic failure model of fault zone was established, the normal fault sliding mechanism and supporting theory were combined to derive the expression of the …
Comprehensive Evaluation Technology And Application Of Grouting Reinforcement Effect For Broken Coal And Rock Mass, Wang Xiaolei, Ji Zhigang, Luo Wenqiang
Comprehensive Evaluation Technology And Application Of Grouting Reinforcement Effect For Broken Coal And Rock Mass, Wang Xiaolei, Ji Zhigang, Luo Wenqiang
Coal Geology & Exploration
Grouting reinforcement of broken coal and rock mass plays an important role in controlling the stability of surrounding rocks, and the grouting effect detection is an important link to ensure the grouting engineering to meet the requirements. The evaluation index was quantitatively analyzed by slurry filling rate method, mechanical parameter method, segmented water injection method, geological radar method, drilling television method and core inspection method. The comprehensive evaluation form of grouting effect was put forward, and the application research was carried out. The results show:The rate of filling slurry and coring was more than 90%; After grouting, the compressive strength …
Deformation Characteristics And Support Timing Of Deep High Stress Roadway, Geng Weile, Dong Ziwen, Guo Shengli, Pi Zikun
Deformation Characteristics And Support Timing Of Deep High Stress Roadway, Geng Weile, Dong Ziwen, Guo Shengli, Pi Zikun
Coal Geology & Exploration
The rock occurrence environment and structural characteristics determine its strength criteria, and affects the mechanical and deformation characteristics of surrounding rock. This paper relies on the deep replacement project of a mine in Yunnan, based on the rock strength criteria, and analyzes the mechanics and deformation characteristics of surrounding rock and the reasonable secondary support time of roadway to decrease the influence of the roadway support effect because of the obvious rheological properties present under high ground stress. The results showed that the min-average simulated deviations mf was generalized H-B criterion which was aimed at the sum of deviation absolute …
Green Strategic Planning Approach For International Shipping Activities, Xiaofang Wu, Luoping Zhang, Huan Feng
Green Strategic Planning Approach For International Shipping Activities, Xiaofang Wu, Luoping Zhang, Huan Feng
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Sustainability is a long-term and ultimate goal for international shipping, although it is slowly making progress. The shipping perspective that moves away from “port-to-port” operations to “door-to-door” services also requires international shipping to take a long-term and holistic view instead of fragmented efforts. How to achieve the long-term sustainability goal becomes a key issue for door-to-door international shipping. Hence, green strategic planning for door-to-door international shipping was proposed with green development that puts forward the eco-centric point of view as its basic theory for sustainability. This study used a strategic decision-making approach, a so-called multi-dimensional decision-making (MDDM), coupled with the …
Umphlett Qci Dec 2019, Natalie A. Umphlett
Umphlett Qci Dec 2019, Natalie A. Umphlett
High Plains Regional Climate Center: Staff Publications
Highlights for the Basin
Temperature and Precipitation Anomalies
Soil Moisture Conditions
Agriculture
Energy
Infrastructure
Temperature
Precipitation
Small Ruminant Health Intervention Calendar In Ethiopia, Mesfin Mekonnen, Ayalew Assefa, Tesfalem Nane, Firdawok Ayele, Asrat Arke, Belay Elias, Barbara Wieland
Small Ruminant Health Intervention Calendar In Ethiopia, Mesfin Mekonnen, Ayalew Assefa, Tesfalem Nane, Firdawok Ayele, Asrat Arke, Belay Elias, Barbara Wieland
Daugherty Water for Food Global Institute: Faculty Publications
Contents
1 Background................................................................................................... 3
2 Developing the health intervention calendar............................................................ 4
The treatment calendar ......................................................... 4 Applying the calendar..................................................................... 5 4 References................................................................... 8
Effect Of Foliar Spray Application Of Zinc Oxide Nanoparticles On Quantitative, Nutritional, And Physiological Parameters Of Foxtail Millet (Setaria Italica L.) Under Field Conditions, Marek Kolenčík, Dávid Ernst, Matej Komár, Martin Šebesta, Martin Urík, Edmund Dobročka, Ivan Černý, Ramakanth Illa, Raghavendra Kanike, Qian Yu, Huan Feng, Denisa Orlová, Gabriela Kratošová
Effect Of Foliar Spray Application Of Zinc Oxide Nanoparticles On Quantitative, Nutritional, And Physiological Parameters Of Foxtail Millet (Setaria Italica L.) Under Field Conditions, Marek Kolenčík, Dávid Ernst, Matej Komár, Martin Šebesta, Martin Urík, Edmund Dobročka, Ivan Černý, Ramakanth Illa, Raghavendra Kanike, Qian Yu, Huan Feng, Denisa Orlová, Gabriela Kratošová
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
It has been shown that the foliar application of inorganic nano-materials on cereal plants during their growth cycle enhances the rate of plant productivity by providing a micro-nutrient source. We therefore studied the effects of foliarly applied ZnO nanoparticles (ZnO NPs) on Setaria italica L. foxtail millet’s quantitative, nutritional, and physiological parameters. Scanning electron microscopy showed that the ZnO NPs have an average particle size under 20 nm and dominant spherically shaped morphology. Energy dispersive X-ray spectrometry then confirmed ZnO NP homogeneity, and X-ray diffraction verified their high crystalline and wurtzite-structure symmetry. Although plant height, thousand grain weight, and grain …
Table Of Contents, The Editors
Trilinear Chart Classification Method Of Mine Water Hazard Type Based On Factors Of Water Recharge, Hu Weiyue, Zhao Chunhu
Trilinear Chart Classification Method Of Mine Water Hazard Type Based On Factors Of Water Recharge, Hu Weiyue, Zhao Chunhu
Coal Geology & Exploration
The results of the classification of hydrogeological types in coal mines are relatively inadequate to reflect the characteristics of water hazards such as water sources and water inrush channels. It is not very instructive to carry out water control work in coal mines starting from the basic elements of mine water hazard formation, this paper analyses the characteristics and harm degree of mine water hazard under different types of mine water sources, water inrush channels and their combination conditions, the water inrush source can be divided into 4 types according to its water-rich degree and supply capacity:weak supply of slow …
Analytical Solution For Surrounding Rock Of Circular Roadway Based On Generalized Smp Criterion Considering Seepage And Dilatancy, Pan Jiliang, Ren Fenhua
Analytical Solution For Surrounding Rock Of Circular Roadway Based On Generalized Smp Criterion Considering Seepage And Dilatancy, Pan Jiliang, Ren Fenhua
Coal Geology & Exploration
Based on the generalized spatially mobilized plane(SMP) criterion, considering intermediate principal stress, pore water pressure and dilatancy characteristics of surrounding rock, an ideal elastic-plastic model of roadway surrounding rock is established. According to the elastic-plastic theory, the unified analytical solutions of stress field, displacement field and radius of plastic zone under seepage flow are obtained. Then, the stress distribution of surrounding rock and the radius of plastic zone calculated by SMP criterion are compared with those calculated by Mohr-Coulomb(M-C) criterion, and the influencing factors such as pore water pressure and dilatancy angle of surrounding rock are analyzed. It is shown …
Identification Model Of The Independence Right-Fuzzy Variable Theory Of Water Inrush Source, Dong Donglin, Li Xiang, Lin Gang, Bian Jianling, Cao Chenglong, Wu Heng
Identification Model Of The Independence Right-Fuzzy Variable Theory Of Water Inrush Source, Dong Donglin, Li Xiang, Lin Gang, Bian Jianling, Cao Chenglong, Wu Heng
Coal Geology & Exploration
In the process of coal mining, mine water hazard accidents occur frequently. In order to find out the water source of mine water inrush quickly and accurately, and reduce the harm caused by mine water inrush to coal mine production, taking Zhaogezhuang mine as an example, and the method of combining independent weight coefficient with fuzzy variable theory was used to select six kinds of hydrochemical indexes of Na+, Ca2+, Mg2+, Cl-, SO42- and HCO3-, 20 sets of water sample data of Zhaogezhuang mine were analyzed and …
Micro Ct-Based Meticulous Characterization Of Porosity Evolution Of Coal In The Process Of Biodegradation, Dong Zhiwei, Guo Hongyu, Xia Daping, Liu Xile, Bai Yang, Zhao Guojun
Micro Ct-Based Meticulous Characterization Of Porosity Evolution Of Coal In The Process Of Biodegradation, Dong Zhiwei, Guo Hongyu, Xia Daping, Liu Xile, Bai Yang, Zhao Guojun
Coal Geology & Exploration
To explore the bio-permeability enhancing effect via methanogen treatment on different rank coals after anaerobic fermentation, micro-CT was used to analyze the change characteristics of pore structure of coal before and after biodegradation. At the same time, the adsorption characteristics of methanogens on the coal surface after anaerobic biodegradation were observed by scanning electron microscopy to analyze the reasons for the effect difference of biological transformation of different rank coals. The results show that the porosity and total throat length of the coal samples biodegraded increase and the connectivity of the pores is enhanced, it is indicated that coal samples …
Comprehensive Outburst Prevention Technology Of Outburst-Prone Coal Seam Uncovered By Crossdrift In Hongshan Coal Mine, Wang Beifang, Liang Bing, Zhang Jing, Chi Haibo, Huang Pujiang
Comprehensive Outburst Prevention Technology Of Outburst-Prone Coal Seam Uncovered By Crossdrift In Hongshan Coal Mine, Wang Beifang, Liang Bing, Zhang Jing, Chi Haibo, Huang Pujiang
Coal Geology & Exploration
Coal and gas outburst is a complex geo-dynamic disaster induced by a coal seam uncovered by crossdrift, threatens the safety and efficient production of coal mines seriously. For this, Hongshan coal mine was selected as engineering background to simulate mechanical response characteristics of surrounding rock during uncovering No.12 coal seam in a gas bursting hazardous zone with FLAC3D software. Then the outburst mechanism during uncovering a coal seam by a crossdrift was revealed, and comprehensive outburst prevention technology combining mine gas pre-drainage and improved metal skeleton was put forward. The results showed that the abutment pressure ahead of the …
Molecular Simulation Of The Influence Of Foam Fracturing Fluid Additives On Coalbed Methane Diffusion, Yang Zhaozhong, Han Jinxuan, Zhang Jian, He Rui, Lu Yanjun, Li Xiaogang
Molecular Simulation Of The Influence Of Foam Fracturing Fluid Additives On Coalbed Methane Diffusion, Yang Zhaozhong, Han Jinxuan, Zhang Jian, He Rui, Lu Yanjun, Li Xiaogang
Coal Geology & Exploration
Materials Studio(MS) software was used to establish a slit pore molecular model which considers the in-teractions among water-bearing coal, foam agent and foam stabilizer. Based on molecular diffusion theory, the diffusion ability of methane molecule respectively affected by four common foam agents and four foam stabilizers was calculated. Compared to original water-bearing coal, self-diffusion coefficient of coalbed methane(CBM) is reduced by 71.3%, 74.7%, 56.3%, 54.0% after adding foaming agents including sodium dodecyl sulfonate(SDS), sodium lauryl sulfate(SLS), sodium dodecyl benzene sulfonate(SDBS) and lycine respectively. Based on adding SDBS into water-bearing coal, the self-diffusion coefficient of CBM is further reduced by 63.2%, …
Reasons Of Low Yield And Stimulation Measures For Vertical Cbm Wells In High-Rank Coal, Jia Huimin, Hu Qiujia, Qi Kongjun, Liu Chunchun, Fan Bin, He Jun
Reasons Of Low Yield And Stimulation Measures For Vertical Cbm Wells In High-Rank Coal, Jia Huimin, Hu Qiujia, Qi Kongjun, Liu Chunchun, Fan Bin, He Jun
Coal Geology & Exploration
The CBM production is usually low and development effect is poor in China, which are mainly due to the poor adaptability of the stimulation measures to the geological conditions. This article, based on the low-yield reasons for vertical CBM wells in Zhengzhuang block in southern Qinshui basin, puts forth corresponding stimulation measures, analyzes the mechanism and the geological adaptability, optimizes the parameters of specific stimulation measures and carries out pilot test. The research and practices show that in deeply buried area, fractures are difficult to form, and re-fracturing technology can make the fracture turn and increase the crack length, which …
Estimation Method And Application Of Free Gas Content In Coal, Jiang Wenping, Zhang Qun, Zhang Peihe, Dong Mintao, Tian Xinjuan, Ru Ting
Estimation Method And Application Of Free Gas Content In Coal, Jiang Wenping, Zhang Qun, Zhang Peihe, Dong Mintao, Tian Xinjuan, Ru Ting
Coal Geology & Exploration
In order to study the distribution characteristics of free gas content in coal reservoirs, based on the understanding that free gas mainly exists in coal pores, the estimation method of free gas content is optimized. Based on the test data of coalbed methane arameters of 42 groups of coals with different ranks from lignite to anthracite in typical coal-bearing areas of China, the free gas content of different coal samples were calculated by using the optimized method of free gas content estimation, and compared with the results of desorption gas content. The results show that the ratio of free gas …
Analysis On The Type Of Reservoir Pressure Drop And Drainage Control Of Coalbed Methane Well In The Southern Block Of Shizhuang, Yi Yongxiang, Tang Shuheng, Zhang Songhang, Yan Xinlu, Wang Kaifeng, Dang Feng
Analysis On The Type Of Reservoir Pressure Drop And Drainage Control Of Coalbed Methane Well In The Southern Block Of Shizhuang, Yi Yongxiang, Tang Shuheng, Zhang Songhang, Yan Xinlu, Wang Kaifeng, Dang Feng
Coal Geology & Exploration
In order to fully understand the reservoir pressure variation characteristics of coalbed methane wells in the southern block of Shizhuang and based on the analysis of reservoir geological parameters and the analysis of actual production data, the reservoir pressures of different types of production wells are analyzed. The specific analysis of the drainage control and reservoir sensitivity effects is also carried out based on the abnormal wells. The results showed that the reservoir lamination of coalbed methane wells in the southern block of Shizhuang can be divided into three types, namely type of rapid pressure drop, type of medium-term stability …
Development And Test Of Self-Adjusting Deflected Wellhead Sealing Device For Coalbed Methane Wells, Pang Tao
Development And Test Of Self-Adjusting Deflected Wellhead Sealing Device For Coalbed Methane Wells, Pang Tao
Coal Geology & Exploration
In order to solve the problem of fluid and gas leakage in coal seam gas well, a self-adjusting deflected wellhead sealing device suitable for coal seam gas wells is developed. The device consists of three parts:Smooth rod sealing box, self-adjusting deflected part and lower sub. The self-adjusting deflected part is a smart combination of universal joint and high pressure flexible rubber tube, which makes the sealing box and the polished rod always keep good concentricity. Practical application shows that this kind of polished rod sealing device has reliable sealing performance, simple structure and the prospect of popularization and application.
Experimental Study On Contact Angle And Pore Characteristics Of Unsaturated Loess, Jing Yanlin, Wang Hao, Tao Chunliang, Yang Lina, Liu Jianwei, Wen Xin
Experimental Study On Contact Angle And Pore Characteristics Of Unsaturated Loess, Jing Yanlin, Wang Hao, Tao Chunliang, Yang Lina, Liu Jianwei, Wen Xin
Coal Geology & Exploration
Contact angle and pore size are important factors affecting soil wettability, permeability and capillarity. In order to further understand the capillary characteristics and permeability of unsaturated loess, the contact angle test and mercury intrusion test of unsaturated loess were carried out. The relationship between pore size and contact angle was analyzed in details. Moreover, the variation of pore and contact angle with depth was discussed. It is found that the contact angle of loess in the dry state is higher than the contact angle of loess in the natural state; as the depth of the formation increases, the contact angle …
Influence Of Loading Rate On The Fracture Characteristics Of Large-Size Specimen, Chen Juntao, Li Ming, Cheng Binbin, Yang Fan, Men Huili, Shao Zhujuan
Influence Of Loading Rate On The Fracture Characteristics Of Large-Size Specimen, Chen Juntao, Li Ming, Cheng Binbin, Yang Fan, Men Huili, Shao Zhujuan
Coal Geology & Exploration
According to the high mining speed of modern mines in China, the fracture characteristics of rock mass under different uniaxial loading rate was systematically analyzed. Based on the geological condition of deep rock mass in Jining area, the optimum mortar composed of 425 Portland cement, sand with particle size less than 2 mm, gypsum, water and high efficient water reducer was used, which had the mechanical properties similar to real rock mass was ascertained. Applying the triaxial rock test system of coupled stress-seepage and PCI-2 real-time monitoring system of AE, the fracture process of specimens of large size under biaxial …
A New Instability Criterion Of Double Strength Reduction Method For Slope, Fang Hongwei, Wu Jianxun, Hou Zhenkun
A New Instability Criterion Of Double Strength Reduction Method For Slope, Fang Hongwei, Wu Jianxun, Hou Zhenkun
Coal Geology & Exploration
Based on the slip line field theory(SLFT), a new instability criterion of strength reduction method with double re-duction factors for homogeneous slopes was proposed. It is judged that the slope is in the limit equilibrium state when the slope contour under limit equilibrium state(abbreviated as the critical slope contour) calculated by the SLFT intersects with the slope line at the toe. The critical curve was constructed in the plane of the inverse of the double reduction factors, and the comprehensive safety factor was derived. The slope calculation results show that three relative position relationships between the initial point and the …
The Effect Of Viscoelasticity And Velocity Anisotropy On The Reflections Of A Thin Bed, Chen Benchi, Wang Chao, Chen Changxing, Shi Lei
The Effect Of Viscoelasticity And Velocity Anisotropy On The Reflections Of A Thin Bed, Chen Benchi, Wang Chao, Chen Changxing, Shi Lei
Coal Geology & Exploration
The coal seam is a typical thin bed characterized by much lower elastic impedance than that of the surrounding rock. Coal seam has viscoelasticity and velocity anisotropy and its reflection amplitude changes with frequency. In order to analyze the effect of viscoelasticity and velocity anisotropy on seismic responses of a thin bed, this paper aims at a thin-bed model with strong impedance contrast and simulates seismic responses under three different assumptions, elastic and velocity isotropy, viscoelastic and velocity isotropy, and viscoelastic and velocity anisotropy, through numerical simulation method based on wave equations. Comparison of these seismic reflections shows that the …
Acquisition Platform Of Frequency Domain Ip Signal, Fu Guohong, Zhang Qianfeng, Cheng Hui, Xie Tiancai
Acquisition Platform Of Frequency Domain Ip Signal, Fu Guohong, Zhang Qianfeng, Cheng Hui, Xie Tiancai
Coal Geology & Exploration
In order to improve the versatility of the induced polarization(IP) signal receiver of traditional frequency domain, a signal acquisition platform was designed, which can acquire and process IP signals of frequency domain such as variable-frequency signals, dual-frequency IP signals, and pseudo-random multi-frequency IP signals and so on. Hardware circuits were established based on STM32 to execute low-pass filtering, program-controlled amplification, analog-to-digital conversion, and data communication. The host computer was developed in LabVIEW to achieve parameter settings, digital filtering, spectrum analysis, amplitude measurement and calculation to obtain target parameters such as PFE, and has waveform display and playback, data storage and …
The Influence Of Grounding Grid On Electromagnetic Detection Of Goaf, Xu Xing, Weng Ling, Li Shiqiang, Liu Guoqiang
The Influence Of Grounding Grid On Electromagnetic Detection Of Goaf, Xu Xing, Weng Ling, Li Shiqiang, Liu Guoqiang
Coal Geology & Exploration
The existence of underground goaf can easily cause tilting and settlement of power towers, which is a major hidden factor in the safe and stable operation of power grid. To detect the mine goaf under the power transmission corridor is of great significance. When there is a grounding grid in the detection area, the grounding grid will have certain influence on the measured value. In this paper, the detection of mine goaf in the presence of a grounding grid is presented. Based on the theoretical analysis, the mathematical model is built, and the simulation model is conducted. The influence of …
Design And Application Of Multi-Section Bundled Bag Wire-Line Coring Drilling Tools, Han Yi, Zhang Shaohe, Bai Rui, Sun Pinghe, Shu Biao, Cao Han, Zhang Xinxin
Design And Application Of Multi-Section Bundled Bag Wire-Line Coring Drilling Tools, Han Yi, Zhang Shaohe, Bai Rui, Sun Pinghe, Shu Biao, Cao Han, Zhang Xinxin
Coal Geology & Exploration
Because the existing conventional wire-line coring drilling tool lacks the water-proof and core-protecting device, the broken core is easily eroded when the core is drilled in a complicated layer such as loose, weak, broken layers and the core is easy to fall off during the lifting process, so that the coring rate and core quality are not up to the design requirements, and even core can not be taken to. In response to the above problems, a bag-type wire-line coring drilling tool was designed. The drill adds a multi-section bundled bag assembly structure to the conventional wire-line coring drilling tool …