China Safety Science Journal ›› 2020, Vol. 30 ›› Issue (4): 53-59.doi: 10.16265/j.cnki.issn1003-3033.2020.04.009

• Safety engineering technology • Previous Articles     Next Articles

Effective extraction radius of gas drilling in coal seam

ZOU Shichao, XIN Song   

  1. College of Mining and Safety Engineering, Shandong University of Science and Technology, Qingdao Shandong 266590, China
  • Received:2020-01-06 Revised:2020-03-21 Online:2020-04-28 Published:2021-01-27

Abstract: In order to predict effective extraction radius of drilling hole in gas control of coal mine, taking No. 6 coal seam of Sijichun mine in Guizhou Province as an example, a gas seepage model of surrounding units of boreholes was established. Then, gas pressure distribution cloud chart along radial direction at different drilling time was obtained through Comsol numerical simulation. Finally, effective extraction radius was determined based on theoretical derivation and numerical simulation data while considering critical gas pressure (0.5 MPa), and verification was made with on-site test. The results show that relative error rate of theoretical and simulated effective extraction radius is less than 10%, verifying accuracy of both calculation results. Effective radius is linearly dependent on extraction time. Considering its complexity to measure effective radius on site, it can be obtained through theoretical and numerical simulation methods used in this paper, which provides a theoretical basis for underground gas control.

Key words: drilling gas, extraction radius, critical gas pressure, seepage model, distance between boreholes

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