1. Investigation on highly effective depressurization property of dual-power drilling and its application.
- Author
-
LIN Bai-quan, ZOU Quan-le, SHEN Chun-ming, XU You-ping, DAI Hua-ming, and YANG Wei
- Subjects
- *
COAL mining , *DRILLING & boring , *PRESSURE measurement , *RHEOLOGY , *FREE surfaces - Abstract
Based on the effect of depressurization, rapid depressurization property of dual-power drilling was investigated. The realizing condition of dual-power drilling and the principal of helical coal breaking were analyzed theoretically. Adopting the FLAC3D software, the model was established to study the rules of stress revolution around the relaxed slot. Besides, the industrial experiment was conducted. It indicates that the advanced free surface can eliminate the confining pressure and lower the resistance, increasing the drilling rate significantly. The relaxed slot boost the coal mass rheology occur, making the concentration stress move deeper, gas potential energy released, the coal strength enhanced and thus the fatality of outburst removed. Industrial experiment shows that after adopting this measure, the perturbation range enlarges forty times and the depressurization radius four times. The efficiency of gas drainage improves substantially, the fatality of outburst in control region is removed and tunneling progress raises two times. [ABSTRACT FROM AUTHOR]
- Published
- 2013