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Full-Text Articles in Engineering
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 …