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Full-Text Articles in Mining Engineering
Factors Influencing The Build-Up Rate Of Small-Diameter Rotary Steerable Systems In Underground Coal Mines, Yang Dongdong, Li Quanxin, Zhang Youzhen, Chen Long, Chu Zhiwei, Jiang Bici, Wang Bo, Yan Wenchao
Factors Influencing The Build-Up Rate Of Small-Diameter Rotary Steerable Systems In Underground Coal Mines, Yang Dongdong, Li Quanxin, Zhang Youzhen, Chen Long, Chu Zhiwei, Jiang Bici, Wang Bo, Yan Wenchao
Coal Geology & Exploration
Objective Intelligent drilling represents an important part of intelligent coal mine construction. However, measurement-while-drilling (MWD) directional drilling, the core of underground intelligent drilling operations, currently suffers from several limitations, including the high dogleg severity of wellbore trajectories, low drilling efficiency, and poor hard-rock penetration. Rotary steerable system (RSS) technology has emerged as a key approach to addressing these limitations owing to its high-precision control on drilling trajectories. Methods This study systematically analyzed the factors influencing the build-up rate of small-diameter, push-the-bit RSSs using a modified 3-point circle method and the longitudinal beam bending method. Through theoretical modeling, the coupled impacts …
Sealing Performance Evaluation Criteria And Profile Optimization Of The Volumetric Cavities Of Positive Displacement Motors For Directional Drilling, Kuang Yuchun, Hu Xin, Zhou Jingpei, Luo Jinwu, Liu Yihui, Han Yiwei
Sealing Performance Evaluation Criteria And Profile Optimization Of The Volumetric Cavities Of Positive Displacement Motors For Directional Drilling, Kuang Yuchun, Hu Xin, Zhou Jingpei, Luo Jinwu, Liu Yihui, Han Yiwei
Coal Geology & Exploration
Objective Constrained by complex stratigraphic conditions in underground coal mines, directional drilling faces challenges such as low efficiency when encountering medium-hard and hard formations. Positive displacement motors (PDMs) with a diameter of 89 mm are commonly used for directional drilling. Their efficiency is primarily influenced by the sealing performance of their volumetric cavities, which further significantly affects the drilling efficiency. Methods Based on the structural characteristics of the three-dimensional (3D) volumetric cavities of PDMs and the simulation method of two-way fluid-structure interactions, this study proposed the criteria for quantitatively evaluating the efficiency and volumetric cavity performance of PDMs, followed by …
Underground Tunnel Drilling Technology And Equipment For Coal Mines In China: A 50-Year Retrospective And Prospects, Tian Hongliang, Li Wangnian, Li Quanxin, Yao Ke, Liu Jianlin, Chang Jianghua
Underground Tunnel Drilling Technology And Equipment For Coal Mines In China: A 50-Year Retrospective And Prospects, Tian Hongliang, Li Wangnian, Li Quanxin, Yao Ke, Liu Jianlin, Chang Jianghua
Coal Geology & Exploration
Bcakground Underground tunnel drilling in coal mines represents an indispensable key means for the safe and efficient coal mining, precise disaster prevention and control, and geological transparency of coal mines. This study presents a systematic review of the development history of underground tunnel drilling technology and equipment for coal mines in China over the past 50 years, during which the technology and equipment have evolved from technology introduction to independent innovation and from following to keeping pace with and even to overtaking international counterparts.Advances Initially, this study expatiates on both the important position of coal resources in the national …
Application Of Long-Distance Tunneling And Detection For Advance Detection In Excavation Using Shield Tunneling Machines, Chen Chao, Li Ping, Li Wei, Wei Rong
Application Of Long-Distance Tunneling And Detection For Advance Detection In Excavation Using Shield Tunneling Machines, Chen Chao, Li Ping, Li Wei, Wei Rong
Coal Geology & Exploration
Objective and Method During the rapid excavation process using shield tunneling machines in coal mines, the advance detection of concealed geological anomalies encounters challenges of limited space and insufficient accuracy. To overcome these issues, this study investigated highly-located drainage roadway 3211 in the Tiandi Wangpo Coal Mine in Jincheng City, Shanxi Province using the long-distance tunneling and detection technology, the core of which is long directional boreholes combined with comprehensive borehole geophysical prospecting. This roadway is located in the roof of the No.3 coal seam, and it is necessary to conduct shield construction in the stable sandstone layer located from …
Construction And Application Of A Model For Drainage Via Directional Boreholes Against Water Hazards In Deep Vertical Shafts, Zhao Chunhu, Zhu Mingcheng, Ji Yadong, Wang Shidong, Zhang Wenzhong, Zhu Kaipeng, Liu Yingfeng, Shang Hongbo, Li Chaofeng, Fan Min, Li Kai
Construction And Application Of A Model For Drainage Via Directional Boreholes Against Water Hazards In Deep Vertical Shafts, Zhao Chunhu, Zhu Mingcheng, Ji Yadong, Wang Shidong, Zhang Wenzhong, Zhu Kaipeng, Liu Yingfeng, Shang Hongbo, Li Chaofeng, Fan Min, Li Kai
Coal Geology & Exploration
Background Vertical shafts are typically employed in the deep mining areas of Jurassic coalfields in western China. However, the direct exposure of extremely thick Cretaceous aquifers frequently leads to significant water inflow in shafts. Meanwhile, the continuous sand-carrying water inflow and scouring in vertical shafts pose serious safety hazards to the overall quality of shaft walls. Methods In underground water exploration and discharge boreholes, water outlets are below the floors of aquifers to be drained. This allows unpowered water discharge. In other words, water can flow out naturally. By fully leveraging this advantage, combined with the favorable condition of spatial …
A Model Predictive Control Method For Directional Borehole Trajectories In Underground Coal Mines, Li Hao, Yao Ningping, Lu Chengda, Zhang Jinbao, Wei Hongchao, Wu Jiajun, Li Jinyu
A Model Predictive Control Method For Directional Borehole Trajectories In Underground Coal Mines, Li Hao, Yao Ningping, Lu Chengda, Zhang Jinbao, Wei Hongchao, Wu Jiajun, Li Jinyu
Coal Geology & Exploration
Objective It is challenging to control the borehole trajectories during directional drilling in complex strata in underground coal mines, resulting in significant deviations from the designed trajectories. Given this, this study proposed a method for tracking and controlling directional borehole trajectories based on model predictive control (MPC). Methods Focusing on the directional drilling process conducted using a screw drill, this study investigated the movement patterns of the directional screw drill by analyzing the characteristics of directional drilling in complex strata in underground coal mines. Based on the kinematic theory, this study developed a borehole trajectory extension model for sliding directional …
Key Technology And Practice Of Deep Borehole Pneumatic Directional Drilling In Broken-Soft Coal Seam In Yangquan Mining Area, Liu Fei, Li Quanxin, Fang Jun, Liu Jianlin, Yang Weifeng, Chu Zhiwei, Zhao Jianguo, Wang Siyi
Key Technology And Practice Of Deep Borehole Pneumatic Directional Drilling In Broken-Soft Coal Seam In Yangquan Mining Area, Liu Fei, Li Quanxin, Fang Jun, Liu Jianlin, Yang Weifeng, Chu Zhiwei, Zhao Jianguo, Wang Siyi
Coal Geology & Exploration
Objective In response to the need for precise, proactive, and regional management of gas in the broken-soft coal seam of the Yangquan Mining Area, a technical scheme utilizing pneumatic directional drilling for pre-drainage boreholes was proposed. Methods Based on the analysis of the technical challenges in pneumatic directional drilling, a series of technologies suitable for the broken-soft coal seam in the Yangquan Mining Area were developed. These include stable operation technology for pneumatic downhole motors, precise control technology for drilling boreholes, efficient deep-hole slag discharge technology, and pneumatic milling and salvage technology. The pneumatic directional drilling equipment was optimized, and …
Design Of Attitude Monitoring System For Directional Drilling Continuous Coring Tools, Lin Tingting, Liu Zekai, Ma Yinlong, Zhu Jinbao
Design Of Attitude Monitoring System For Directional Drilling Continuous Coring Tools, Lin Tingting, Liu Zekai, Ma Yinlong, Zhu Jinbao
Coal Geology & Exploration
Directional drilling continuous coring, as an emerging geological exploration technique, holds vast potential in the field of mineral resource exploration. To facilitate the development of directional continuous coring tools with proprietary intellectual property rights, an attitude monitoring system based on attitude sensing and wireless communication technology was designed in this paper. Concerning the hardware system design, the MPU9250 attitude sensor and STM32F103C8T6 main control chip were adopted to monitor the attitude change of drilling tools, where the communication through geological layers was achieved using a LoRa wireless module. Additionally, to accommodate the structural of the drilling tool and the requirements …
Numerical Simulation Of Grout Diffusion Under Coal Seam Floor And Analysis Of Influencing Factors, Guo Yan, Gui Herong, Wei Jiuchuan, Hong Huang, Guo Xiangdong, Cui Yali, Ye Shuang, Li Jun
Numerical Simulation Of Grout Diffusion Under Coal Seam Floor And Analysis Of Influencing Factors, Guo Yan, Gui Herong, Wei Jiuchuan, Hong Huang, Guo Xiangdong, Cui Yali, Ye Shuang, Li Jun
Coal Geology & Exploration
Ground high-pressure advanced regional grouting has become the preferred engineering method for the prevention and control of water disasters in coal mines. The diffusion mechanism of grout has received widespread attention, and the design of branch hole spacing mostly relies on the on-site experience, which has a certain degree of blindness and restricts the effectiveness and efficiency of the project. Based on the actual working conditions of grouting site in Hengyuan Coal Mine, Huaibei Coalfield, the numerical simulation was performed with the COMSOL Multiphysics software for the high-pressure grout diffusion in the floor area of the ground directional drilling coal …
Analysis And Jet Drilling Test Of Coiled Tubing Drilling String For Underground Coal Mine, Yao Ningping, Wang Li, Zhang Jinbao, Dou Xuqian, Wei Hongchao
Analysis And Jet Drilling Test Of Coiled Tubing Drilling String For Underground Coal Mine, Yao Ningping, Wang Li, Zhang Jinbao, Dou Xuqian, Wei Hongchao
Coal Geology & Exploration
Due to continuous tripping, uninterrupted circulation and other technical advantages, coiled tubing drilling has become one of the fastest developing oil-drilling-technologies in recent years. Developing the coiled tubing drilling technology for underground coal mine is an essential technical means to realize “less humanized” or even “unhumanized” coal drilling. Aiming at solving the key problems existing in the application of this technology in underground coal mine, such as pipe string optimization and drilling method, the coiled tubing jet directional drilling method was proposed. According to the mud pump capacity and borehole depth design for underground coal mine drilling, the fluid friction …
Techniques For Prevention And Control Of Ordovician Limestone Water Disasters Based On Modified Water Inrush Coefficient Method, Li Kai, Li Xiaolong
Techniques For Prevention And Control Of Ordovician Limestone Water Disasters Based On Modified Water Inrush Coefficient Method, Li Kai, Li Xiaolong
Coal Geology & Exploration
There are technical problems in preventing and controlling Ordovician limestone water disasters during mining above ultra-thin aquifuges, such as those of the lower coal group in Weibei Coalfield. At Sangshuping Coal Mine, horizontal directional drilling technology was used to develop water prevention and control ideas of Ordovician limestone top utilization and grouting transformation. Firstly, considering the loss of water resistance in the floor failure zone, the water inrush coefficient method was used to determine the critical thickness of Ordovician limestone top utilization and grouting transformation. The directional drilling exploration was carried out by drilling from the two opposite ends of …
Study And Application On Multi Branch Point Sampling Drilling Technology Of Coal Seam Floor Borehole, Chu Zhiwei, Long Weicheng, Jia Bingyi, Liu Fei
Study And Application On Multi Branch Point Sampling Drilling Technology Of Coal Seam Floor Borehole, Chu Zhiwei, Long Weicheng, Jia Bingyi, Liu Fei
Coal Geology & Exploration
According to the technical requirements of long-distance gas parameter measurement, gas extraction borehole design guidance, and extraction evaluation for broken soft coal seam, the multi branch point sampling drilling method of coal seam floor borehole was proposedand its sampling drilling process was formulated on the basis of analyzing existing problems of sampling and drilling technology. Furthermore, the key drilling technologies such as accurate drilling trajectory control and “mechanical + hydraulic” efficient slag removal were developed. The equipment of drilling and sealed sampling were introduced. The application test was carried out in a coal mine in Suzhou, Anhui Province, in which …
Powder Discharge Characteristics Of Pneumatic Double Pipe Directional Drilling In Broken Soft Coal Seams And Its Application, Nie Chao, Wang Yi, Yao Yafeng, Hong Jianjun
Powder Discharge Characteristics Of Pneumatic Double Pipe Directional Drilling In Broken Soft Coal Seams And Its Application, Nie Chao, Wang Yi, Yao Yafeng, Hong Jianjun
Coal Geology & Exploration
To study the influence of casing, casing bit size and casing rotational speed on pulverized coal discharge in double pipe directional drilling technology, three kinds of casing and casing bits in different sizes are designed respectively against the background of pneumatic double pipe directional drilling in the broken soft coal seam, the changes of the discharge rate and outlet velocity of pulverized coal under different combinations are analyzed, and the influence law of different casing rotational speeds on the suspension rate and conveying trajectory of pulverized coal are obtained. The numerical simulation results show that the ø120/96 mm casing with …
Resistivity Detection And Its Application In Underground Coal Mine Directional Boreholes, Li Bofan, Liu Lei, Fan Tao, Jiang Qiping, Wang Jie
Resistivity Detection And Its Application In Underground Coal Mine Directional Boreholes, Li Bofan, Liu Lei, Fan Tao, Jiang Qiping, Wang Jie
Coal Geology & Exploration
The working face threatened by high gas or Ordovician limestone water pressure generally adopts directional drilling technology to carry out fracturing or grouting works at the bottom of the working face before mining to ensure the safety of mining. In-hole probing in directional boreholes in the bottom plate can reveal the hidden structures in the working face in a more detailed way, and can also realize “one hole for multiple uses”. In order to solve the detection problem in the directional drilling, a method of DC resistivity detection in the horizontal directional drilling is proposed. To solve the problem of …
Design And Application Of Pdc Bit For Large Diameter Directional Drilling Of Coal Seam Roof With Double Stage And Double Speed, Gao Xiaoliang, Ju Pei, Zhao Jianguo
Design And Application Of Pdc Bit For Large Diameter Directional Drilling Of Coal Seam Roof With Double Stage And Double Speed, Gao Xiaoliang, Ju Pei, Zhao Jianguo
Coal Geology & Exploration
The development of large diameter directional drilling technology has provided technical support for the extraction of gas in the upper corner of the goaf by "replacing roadway with borehole". At present, conventional large-diameter drilling mainly adopts the step-by-step hole-forming method, which solves the problem of insufficient power of large-diameter drilling equipment in underground coal mines. However, step-by-step reaming requires multiple times of lifting and lowering, long auxiliary time and intensive labor of the workers. In order to improve the drilling efficiency of large-diameter holes in the coal roof, a double stage drilling process with two speeds was developed. The process …
Application Of Air Foam Composite Directional Drilling Technology In Broken Soft Coal Seams, Liu Jianlin, Fang Jun, Chu Zhiwei, Yang Weifeng
Application Of Air Foam Composite Directional Drilling Technology In Broken Soft Coal Seams, Liu Jianlin, Fang Jun, Chu Zhiwei, Yang Weifeng
Coal Geology & Exploration
In order to meet the requirements of air screw motor cooling and lubrication, coal dust removal treatment at the orifice and water outlet disposal in the air directional drilling, an air foam composite directional drilling technology for broken soft coal seams has been developed based on the analysis of drilling slag migration characteristics of air directional drilling. The key technologies such as stable and efficient foaming, "mechanical + foam" composite slag discharge and "air + foam" composite drilling were integrated. The technology was also equipped with directional drillrig, foam generation perfusion system, air screw motor, special-shaped drill pipe and measurement …
Exploration Method Of Underground Geological Anomaly And Its Application Based On Directional Drilling, Fang Jun
Coal Geology & Exploration
Exploration method of underground geological anomaly and its application based on directional drilling
Directional Drilling Technology And Equipment Of Pneumatic Screw Motor In Soft Seam, Zhang Jie, Wang Yi, Huang Hanjing
Directional Drilling Technology And Equipment Of Pneumatic Screw Motor In Soft Seam, Zhang Jie, Wang Yi, Huang Hanjing
Coal Geology & Exploration
Aiming at the drilling problems of shallow depth, uncontrollable trajectory and blind area of extraction in soft coal seam, the directional drilling technology of pneumatic screw motor was invented, and the directional drilling equipment consisting of pneumatic screw motor, narrow structure directional drilling rig and MWD system were formed. The air directional drilling technology and hole-completion technology were studied and developed. The technology of drilling and hole-completion solves the problem of long-distance safe drilling and hole protection of directional drilling along soft coal seam. The technology has been successfully tested in a coal mine, Huainan, with 30 test boreholes with …
Progress Of Drilling Technologies And Equipments For Complicated Geological Conditions In Underground Coal Mines In China, Yao Ningping, Wang Yi, Yao Yafeng, Song Haitao, Wang Li, Peng Tao, Sun Xinsheng
Progress Of Drilling Technologies And Equipments For Complicated Geological Conditions In Underground Coal Mines In China, Yao Ningping, Wang Yi, Yao Yafeng, Song Haitao, Wang Li, Peng Tao, Sun Xinsheng
Coal Geology & Exploration
According to the drilling technology requirements and problems under complicated geological conditions, such as broken soft coal seam, hard rock, rockburst strata, fractured zone, water-sensitive strata, etc, the research and application of drilling technology and screen pipe protection in broken soft coal seam, comb-like directional drilling technology in broken soft coal seam, high-level directional drilling technology in complicated roof strata, full-section across-layer drilling technology of hard rock, and drilling technology for pressure relief in rockburst strata were summed. This paper puts forward the research approaches of the technology and equipment of double-pipes directional drilling and rotary directional drilling in broken …
Development Of Small Diameter Hydraulic Agitator With Cable For Directional Drilling In Underground Coal Mine, Wang Li, Xu Baolong, Wang Yi, Huang Hanjing, Jia Mingqun, Ma Bin
Development Of Small Diameter Hydraulic Agitator With Cable For Directional Drilling In Underground Coal Mine, Wang Li, Xu Baolong, Wang Yi, Huang Hanjing, Jia Mingqun, Ma Bin
Coal Geology & Exploration
Aiming at the problems of large drilling pressure, low drilling efficiency and limited hole depth caused by the backing effect of drill string during deep hole directional drilling in underground coal mine, the technical idea of using hydraulic agitator was proposed. The ø89 mm small diameter hydriculic agitator was designed based on valve principle, the exciting force, excitation frequency were identified, and the cabled sub was developed. The performance parameters of hydraulic agitator with disc spring and cylindrical spring were tested. The results show that when the flow rate of 300 L/min the disc spring hydraulic agitator has the maximum …
Development Of Impact Screw Motor, Wang Siyi, Li Quanxin, Liu Jianlin, Zhao Jiangpeng, Yang Dongdong
Development Of Impact Screw Motor, Wang Siyi, Li Quanxin, Liu Jianlin, Zhao Jiangpeng, Yang Dongdong
Coal Geology & Exploration
Aiming at the problems of low efficiency and high consumption of bits and drilling tools in drilling hard rock with conventional single bend screw motor, an impact screw motor is developed by adding an impact mechanism between the universal shaft of a common screw motor and the drill bit. The impact screw motor has dual functions of impact and orientation. The structure and the working principle of impact mechanism, the design of key components and the characteristics of the impact screw motor are introduced. Laboratory tests were carried out on the φ89 mm impact mechanism, and the peak impact …