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Full-Text Articles in Engineering
Research Status And Development Trend Of Near-Bit Mwd In Underground Coal Mine, Hao Shijun, Chu Zhiwei, Li Quanxin, Fang Jun, Chen Long, Liu Jianlin
Research Status And Development Trend Of Near-Bit Mwd In Underground Coal Mine, Hao Shijun, Chu Zhiwei, Li Quanxin, Fang Jun, Chen Long, Liu Jianlin
Coal Geology & Exploration
Near-bit meusurement while drilling (MWD) integrates several key technologies such as near-bit multi-parameter measurement, power supply and communication across positive displacement motor drills, turbine continuous power generation and high-speed mud pulse wireless transmission, capable of obtaining various types of parameters near the bit. It is one of the key components of intelligent drilling technology in underground coal mine. Herein, the limitation of the existing technology applied in coal mine was analyzed with full reference to the development experience and development path of near-bit MWD in the field of surface oil and gas drilling. Meanwhile, the research idea of near-bit MWD …
Status And Prospects Of Fully Mechanized Mining Technology In Vietnam Coal Mines From 2005 To 2020, Hai Duong Duc, Quang Dao Hong, Viet Phan Van, Thang Ngo Van
Status And Prospects Of Fully Mechanized Mining Technology In Vietnam Coal Mines From 2005 To 2020, Hai Duong Duc, Quang Dao Hong, Viet Phan Van, Thang Ngo Van
Journal of Sustainable Mining
This paper analyzes the achievement and the failures of applying the mechanized mining method in underground coal mines by the Vietnam National Coal – Mineral Industries Holding Corporation Ltd. (VINACOMIN) for 15 years (from 2005 to 2020). It also proposes the recommendations for developing mechanized mining in order to improve coal production, productivity and safety management for the sustainable development of Vietnam’s underground coal mining in the period 2021-2025
Design And Application Of Anti-Drop Drill Pipe With Fracture Self-Locking Function, Dong Changle
Design And Application Of Anti-Drop Drill Pipe With Fracture Self-Locking Function, Dong Changle
Coal Geology & Exploration
Drill pipe will inevitably break and drop during its long-term service, which not only seriously affects the drilling efficiency and the rate of hole formation, but also brings great economic losses to coal mines. In terms of drill pipe drop caused by the random fracture during drilling, the shortcomings of fishing tap were pointed out. By analyzing the fracture characteristics of drill pipe, it is concluded that the key to solve the problem of drill pipe drop is to develop the axial connection technology after the fracture of pin joint. Herein, an active anti-drop technology with fracture self-locking function was …
Image Sharpening Method Of Automatic Loading And Unloading Drill Pipe Target In Underground Coal Mine, Yao Ningping, Liang Chunmiao, Yao Yafeng, Song Haitao
Image Sharpening Method Of Automatic Loading And Unloading Drill Pipe Target In Underground Coal Mine, Yao Ningping, Liang Chunmiao, Yao Yafeng, Song Haitao
Coal Geology & Exploration
Due to the space limitation of underground roadway in coal mine, the drilling robot is designed with two independent systems, i.e., the drilling system and the drilling pipe loading and unloading system, which are in flexible layout. Using the monocular visual identification based on cooperative target, the drilling system is associated with the drilling pipe loading and unloading system for the cooperative operation of the two systems to deliver the drill pipe. However, there are problems such as borehole cinder, cooperative target polluted by sewage, high dust concentration, low visibility, low luminance of artificial light source, uneven illumination resulting in …
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 …
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 …
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, …
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 …
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 …
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 …
Directional Drilling Technology And Equipment For Gas Drainage In Large Panel Of Underground Coal Mines, Xu Chao, Jiang Lei, Chen Pan, Zhang Di
Directional Drilling Technology And Equipment For Gas Drainage In Large Panel Of Underground Coal Mines, Xu Chao, Jiang Lei, Chen Pan, Zhang Di
Coal Geology & Exploration
In recent years, with the progress of directional drilling technology and equipment in underground coal mines, a new model of advanced and comprehensive control of gas in the large panel of Baode Coal Mine is formed by covering the whole work with ultra-long directional drilling along the coal seam, hence the panel of the unexcavated roadway can be fully pre-pumped in advance to avoid gas overrun. As gas extraction in large panel requires a single construction along the coal seam borehole to run through the whole working face length, this paper starts from the construction technology of ultra-long directional drilling …
Practice Of Enhanced Gas Extraction By Staged Fracturing With Comb-Shaped Long Hole In Coal Mine Roof, Jia Bingyi, Chen Dongdong, Wu Jie, Sun Siqing, Wang Jianli, Zhao Jizhan, Zhang Jie
Practice Of Enhanced Gas Extraction By Staged Fracturing With Comb-Shaped Long Hole In Coal Mine Roof, Jia Bingyi, Chen Dongdong, Wu Jie, Sun Siqing, Wang Jianli, Zhao Jizhan, Zhang Jie
Coal Geology & Exploration
In order to solve the problems of drilling construction difficulty, low gas drainage concentration, poor drainage effect and inability to realize the predrainage of large area, based on the existing directional drilling technology and hydraulic fracturing technology in coal mines, combined with the previous research results, the staged hydraulic fracturing technology of comb-shaped long borehole in roof was proposed, and the field test was carried out in Sangshuping No.2 well in Hancheng mining area.The test results show that the main hole length of comb-shaped hole in roof was 588 m, including 8 branch holes, the total drilling footage was 1 …
Research Progress Of Drilling And Borehole Completion Technologies In Broken Soft Coal Seam In Underground Coal Mine, Wang Li, Yao Ningping, Yao Yafeng, Wang Yi, Zhang Jie, Fang Jun, Wei Hongchao
Research Progress Of Drilling And Borehole Completion Technologies In Broken Soft Coal Seam In Underground Coal Mine, Wang Li, Yao Ningping, Yao Yafeng, Wang Yi, Zhang Jie, Fang Jun, Wei Hongchao
Coal Geology & Exploration
In China, broken soft coal seams are in many strata and widely distributed. It is generally characterized by complex tectonic stress, high gas pressure, low mechanical strength and poor permeability, therefor, the hole is easy to collapse, outburst, which will probably cause many problems such as drilling difficulties, frequent accidents in the hole, inadequate hole depth, borehole blockage, drainage blind area and so on. With the continuous increase of coal mining depth, it is more difficult for drilling and completion in broken soft coal seam. Therefore, the high efficiency, deep hole and precise drilling technology, as well as the completion …
Development Situation And Prospect Of Luffing Mechanism Of Drilling Rig In Underground Coal Mine, Yao Yafeng, Yao Ningping, Peng Tao
Development Situation And Prospect Of Luffing Mechanism Of Drilling Rig In Underground Coal Mine, Yao Yafeng, Yao Ningping, Peng Tao
Coal Geology & Exploration
The luffing mechanism of drilling rig is used to adjust the opening parameters of the borehole, that is, azimuth angle, inclination angle, and height. According to the structural differences of different types of drilling rig and the construction characteristics of borehole in underground coal mine, this paper summarizes the adjustment requirements to opening parameters and proposes the research goal, which can rapidly and accurately adjust the parameters of the borehole and safeguard the stability of drilling construction. It is concluded that the luffing mechanism of drilling rig in underground coal mine has overall characteristics of small size, large adjustment range …
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 …
Present Situation And Prospect Of Drilling Equipment Technology In Coal Mine, Yao Ke, Tian Hongliang, Yao Ningping, Yin Xinsheng, Fang Peng, Yao Yafeng, Wu Di, Wang Longpeng
Present Situation And Prospect Of Drilling Equipment Technology In Coal Mine, Yao Ke, Tian Hongliang, Yao Ningping, Yin Xinsheng, Fang Peng, Yao Yafeng, Wu Di, Wang Longpeng
Coal Geology & Exploration
After over 40 years of development, the technology of underground drilling equipment, vital to guarantee safety and efficient production for coal mines, has been improved greatly. Combining with the characteristics of products, types of technology and application domains, the development of domestic and foreign of underground drilling equipment for coal mines are introduced, the application effects and existing problems of drilling machines are analyzed, especially the development experience and current situation of domestic drilling machines are summarized, detailing on technology status of the five most representative models, such as the split type drill, caterpillar drill, electro-hydraulic control drill, rubber wheel …