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Full-Text Articles in Engineering
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 …
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 …
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