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Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

2019

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China Coal Technology and Engineering Group (CCTEG)

Hard rock

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Development Of Impact Screw Motor, Wang Siyi, Li Quanxin, Liu Jianlin, Zhao Jiangpeng, Yang Dongdong Oct 2019

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 …


Hole-Bottom Hydraulic Pressurization Technology For Directional Drilling In Hard Rock In Underground Coal Mines, Xu Baolong, Yao Ningping, Wang Li, Cao Jing, Dou Xuqian Feb 2019

Hole-Bottom Hydraulic Pressurization Technology For Directional Drilling In Hard Rock In Underground Coal Mines, Xu Baolong, Yao Ningping, Wang Li, Cao Jing, Dou Xuqian

Coal Geology & Exploration

In order to solve the problem of large feeding pressure, low drilling efficiency and limited hole depth caused by the backing effect of drill string during directional drilling of deep hole in underground coal mines, a technical idea of using hydraulic tool to increase WOB was proposed. The structural design of the hydraulic pressurizer at the bottom of the hole was carried out by drawing on the structure of the hydraulic pressurizer in the field of oil drilling and combining the nearly horizontal drilling conditions in underground coal mines. The hydraulic parameters were designed by the theoretical calculation and the …