Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 6 of 6
Full-Text Articles in Engineering
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, …
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 …
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 …